Grasses doi: 10.3390/grasses5020021

Authors: Alejandra L. Yezzi Ana J. Nebbia Sergio M. Zalba

Fires are an ecological force that often mediates the balance between native and exotic plants in communities. We monitored post-fire vegetation dynamics in a Pinus pinaster plantation and adjacent grasslands 9, 15, and 18 months after the fire, evaluating structural and compositional changes through multivariate analyses. The invasive alien Acacia longifolia cover increased significantly in the plantation (p = 0.0006), while pine needle cover declined significantly (p = 0.0027), and P. pinaster cover did not change significantly over time (p = 0.063), although it showed an increasing trend towards the late stage. Both A. longifolia and pine needles were negatively associated with native species cover. Native cover remained consistently higher in continuous grasslands, with a significant Time × Site interaction. Post-fire succession in the plantation was associated with sequential abiotic and biotic filters, and the increase in A. longifolia may have contributed to reduced native recovery through competitive effects. These results suggest that fire alone may be insufficient to restore native grassland conditions within afforested systems and that early post-fire control of A. longifolia may be necessary to redirect succession.

Grasses doi: 10.3390/grasses5020020

Authors: Ira Lloyd Parsons Brandi B. Karisch Amanda E. Stone Stephen L. Webb Garrett M. Street

Wearable sensors and remote sensing technologies are rapidly increasing opportunities to measure grazing animal behavior, energetics, and performance in extensive rangeland systems. However, despite significant advances in device capabilities, the livestock sector lacks an ecological framework that connects sensor data to the metabolic processes driving animal growth and efficiency. In this paper, we apply the movement ecology paradigm to grazing beef cattle as a demonstration of how metabolic theory, animal behavior, and landscape heterogeneity interact to influence energy budgets. We first describe the mechanistic relationships among basal metabolism, thermoregulation, activity, and forage intake, highlighting how movement patterns reflect underlying metabolic states. Next, we review key variables measurable through modern sensors, including GPS, accelerometers, rumen temperature boluses, and remote sensing of forage quantity and quality and explain how these data can be integrated into an information system to estimate energy expenditure, resource selection, and physiological stress. Finally, we show how combining movement, behavioral, and landscape data can yield meaningful indicators of performance and health, paving the way for precision livestock management grounded in ecological principles. Integrating metabolic and movement ecology with emerging technologies offers a strong framework for enhancing efficiency, welfare, and sustainability in grazing beef systems.

Grasses doi: 10.3390/grasses5020019

Authors: Juan Mattera Jorge Gonzalo Nicolas Irisarri Gabriela Beatriz Cordon Alejandra Lorena Cuatrin Agustín Alberto Grimoldi

Ecotypic variation in tall fescue (Lolium arundinaceum (Schreb.) Darbysh.), with differences in phenology, may affect the performance of mixtures with alfalfa (Medicago sativa L.). However, the effects of ecotypic variation within mixtures remain largely unexplored. The aim of this study was to evaluate the aerial dry matter (ADM) production and radiation model components of alfalfa–tall fescue mixtures, with particular emphasis on their implications for radiation interception and radiation use efficiency (RUE) at the canopy level. We evaluated from March 2017 to May 2018 in the Pampas (Argentina) monocultures of alfalfa and tall fescue Mediterranean and Continental ecotypes, and their mixtures with a sowing ratio 1:1 under frequent defoliation without fertilization. ADM was higher in alfalfa monoculture and mixture with the Mediterranean ecotype than the mixture with the Continental ecotype (+20%; 3225 kg ha−1). Alfalfa monoculture exhibited the highest radiation interception, whereas the mixture with the Mediterranean ecotype compensated for reduced interception through increased RUE (≈10%). The Continental mixture exhibited lower interception indicating stronger interspecific competition. Tall fescue monocultures were the least productive due to low interception and RUE. These findings highlight the potential of Mediterranean tall fescue ecotype and the importance of species/ecotype selection for grassland productivity.

Grasses doi: 10.3390/grasses5020018

Authors: Abigael Natividad Huaraca-Oré Isabel Cristina Molina-Botero Víctor Alvarado-Bolovich Nicolas DiLorenzo Carlos Gómez-Bravo

The objective of this study was to assess the contribution of oat (Avena sativa L.) and common vetch (Vicia sativa) hay supplementation as a forage-based strategy to improve the environmental and productive performance of grazing systems in the high Andean zone through its effects on enteric methane (CH4) emissions and live weight gain. Twenty heifers grazed native grasses, and only half of the group received the supplement. The experiment was conducted as a crossover design. Methane emissions were quantified through sulfur hexafluoride methodology. Native pastures were characterized by low protein content, while lignin was lower in the oat hay plus common vetch hay than in the native grass mixture. On average, heifers consumed 7 kg dry matter per day (p ≥ 0.05) and ingested 24% more crude protein when supplemented (p = 0.0001). Digestible and metabolizable energy intakes were also significantly higher in supplemented animals (p ≤ 0.05). Live weight change was positive for supplemented animals (245 g/d). Net CH4 production ranged from 179.6 to 196.3 g/d (p = 0.183). However, when CH4 emissions were expressed relative to crude protein or acid detergent lignin intake, supplemented diets were found to emit less than native grass-based diets (p ≤ 0.05). These results suggest that supplementation with oat hay plus vetch is a feeding alternative for heifers during the dry season in the Peruvian Andean region to increase animal productivity without affecting CH4 emissions.

Grasses doi: 10.3390/grasses5020017

Authors: Dayanne Camelo Leila Maria de Sousa Tavares Emanuel Dias Freitas Paulo Furtado Mendes Filho

Neem (Azadirachta indica A. Juss) extracts are widely used in agriculture as organic pesticides, but their effects on soil microbiota are uncertain. This study evaluated the impact of aqueous extracts of neem leaves and seeds on soil microbial activity, maize (Zea mays L.) development, and arbuscular mycorrhizal fungus (AMF) dynamics. The experiment used a 2 × 3 + 1 factorial design, with two extract sources (leaf and seed), three concentrations (5%, 10%, and 20%), and a control. The soil treated with 20% seed extract showed the highest microbial respiration (16,512 mg C-CO2·kg−1·day−1) and total organic carbon (15.10 g·kg−1) but the lowest microbial biomass (1330 mg·kg−1) and microbial quotient (0.10%), indicating a stressed microbial environment. Paradoxically, maize plants under this same treatment exhibited a superior height, stem diameter, and biomass. Furthermore, the AMF spore density significantly increased in the seed extract treatments, suggesting a stress-induced reproductive response. These findings reveal that, although neem seed extract can negatively affect soil microbiota, it promotes maize growth, likely due to its organic and bioactive compounds. Thus, neem extract demonstrates potential as an organic input, but its application must be carefully managed due to potential ecological trade-offs.

Grasses doi: 10.3390/grasses5020016

Authors: Jaime Neftalí Márquez-Godoy Edith Ramírez-Segura Abieser Vázquez-González Alan Álvarez-Holguín Carlos Raúl Morales-Nieto Raúl Corrales-Lerma José Humberto Vega-Mares

Forage grasses are an important component of livestock systems due to their contribution to animal feed, soil conservation, and carbon sequestration. In the face of climate change, analyzing stomatal characteristics allows us to understand the mechanisms of adaptation and tolerance to environmental stress. Therefore, the objective of this study was to determine the stomatal characteristics and trichome density of ten forage grasses present in a pine-oak dominated ecosystem. Sampling was carried out in October and November 2022 on a 1938 ha area. Mature, healthy leaves were selected, and epidermal impressions were obtained from the adaxial and abaxial surfaces using the cyanoacrylate method. Observations were made with an optical microscope at 400× magnification, quantifying stomatal density, trichome density, number of epidermal cells, and stomatal index per mm2. The results indicated that nine species were amphistomatic, while Schizachyrium scoparium exhibited an epistomatic pattern. Muhlenbergia arizonica showed the highest stomatal density, and Setaria parviflora the lowest. It is concluded that there is high stomatal variability among species, highlighting its importance for the management and improvement of pastures.

Grasses doi: 10.3390/grasses5010015

Authors: Bruna Zanini Uzan Luciana Gerdes Waldssimiler Teixeira de Mattos Taise Robinson Kunrath Stela Soares Zamboin Cristina Maria Pacheco Barbosa Gabriela Aferri Flavia Maria de Andrade Gimenes

This study evaluated combinations of defoliation frequencies and intensities to identify grazing strategies that optimize forage accumulation and morphological composition in mixed pastures of Marandu palisadegrass (Urochloa brizantha cv. Marandu) with the legume Macrotyloma axillare. Treatments consisted of pre-grazing heights of 30 and 40 cm (defining defoliation frequency) combined with post-grazing heights of 15 and 20 cm (defoliation intensity), in a 2 × 2 factorial randomized block design with four repetitions. Forage accumulation rate, morphological component mass, and leaf area index (LAI) were evaluated under rotational stocking. The highest forage accumulation rates of grass and its stems occurred at a pre-grazing height of 30 cm. A taller pre-grazing height (40 cm) resulted in greater pre-grazing forage mass, leaf and stem mass of Marandu palisadegrass and LAI, but it also increased the amount of dead material and post-grazing stem mass. The greatest Macrotyloma forage accumulation occurred under grazing strategies of 30–20 cm and 40–15 cm. Lenient defoliation (20 cm post-grazing height) favored post-grazing leaf mass, whereas severe defoliation (15 cm) favored stem mass. Marandu palisadegrass showed higher LAI at 40 cm pre-grazing height (4.7) than at 30 cm (3.6), with slightly greater values under 20 cm (4.3) than 15 cm (4.1) post-grazing height, while Macrotyloma axillare exhibited low LAI. Across all grazing strategies, the legume mass decreased over time. Therefore, future studies should explore alternative grazing strategies and periodic reseeding of Macrotyloma axillare to maintain its presence in mixed tropical pastures.

Grasses doi: 10.3390/grasses5010014

Authors: María Carolina Michelini Santiago Javier Maiale Beatriz Wyss Andrés Alberto Rodríguez

Stress caused by suboptimal temperatures (ST) represents a stress that limits growth in all grasses without inhibiting their activity and induces alterations in photosynthetic performance. We evaluated the responses of photosynthetic parameters and leaf elongation between two groups of grass genotypes with different levels of tolerance to ST, belonging to phylogenetically distant species. Responses to ST depended on the type of parameter and on the genotypic group. Leaf elongation traits showed discriminatory power, especially the area under the leaf elongation curve, which integrated the early and transient effects of stress over time. The photosynthetic parameter PIABS showed lower discriminatory power compared with the area under the leaf elongation curve. However, a deeper analysis of other photosynthetic parameters revealed an increase in energetic connectivity between Photosystem II centers in tolerant, but not in sensitive, genotypes. A subsequent analysis of leaf and cellular parameters of early leaf elongation dynamics indicated that ST reduced meristematic activity in all genotypes, but the tolerant genotype group maintained a greater accumulation of mature cells compared with the sensitive genotype group. Overall, the results suggested a response to ST in tolerant genotypes, but not in sensitive genotypes, related to the early dynamics of leaf and cellular growth parameters to partially compensate for the restrictive effect of ST on leaf elongation not recorded. In parallel, they also indicated a response of the tolerant genotypes to ST in terms of photosynthetic parameters, probably as a pathway to maintain cellular homeostasis, to prevent photooxidative damage in PSII under stress. However, the relationship between both responses does not appear to be strictly linear, but rather would be mediated by coordinated adjustments in the temporal dynamics of growth, suggesting a functional integration between photosynthetic performance and the cellular mechanisms that regulate leaf expansion under ST stress.

Grasses doi: 10.3390/grasses5010013

Authors: Cleber Pereira Alves Baltazar Cirino Junior Ana Karlla Penna Rocha Joyce Naiara Da Silva Domingos Sávio Marques de Menezes Vieira Danielle da Silva Eugênio Cintya Mikaelly Pereira Gaia Souza Maurício Luiz De Mello Vieira Leite Monalisa Alves Diniz Da Silva Thieres George Freire da Silva

When subjected to a combination of abiotic stresses in the field, such as saline and thermal stress, plants can suffer devastating effects on their development. Regarding millet, little is known about the effects of temperature and salinity on its germination and initial development. Therefore, the objective of this study was to evaluate the germination responses and initial development of millet seedlings subjected to thermal and saline stresses. The experiment was conducted in a completely randomized design with 16 treatments in a 4 × 4 factorial scheme, four salinity levels (0.0—control, 100, 200, and 300 mM) and four temperatures (10, 20, 30, and 40 °C). The germination percentage, average germination time, germination speed index, shoot length, and primary root length of seedlings were evaluated. The different salinity concentrations and temperatures significantly influenced all the variables studied, gradually reducing with increasing salinity and decreasing temperature, with optimal ranges at higher temperatures and lower salinity levels. It is concluded that the ideal conditions for germination and initial development of millet are as follows: a temperature between 20 and 30 °C and the absence of salinity. They tolerate concentrations of up to 200 mM and temperatures of 40 °C. On the other hand, high salinity and low temperature can delay and/or inhibit germination.

Grasses doi: 10.3390/grasses5010012

Authors: Gonçalo Tavares Póvoas Luís Silva Susana Dias Paola D’Antonio Fernando Cebola Lidon João Serrano Luís Alcino Conceição

Sorghum is a resilient crop important for sustainable intensification in semi-arid regions, yet the impact of variable seeding rates on its early development remains under-researched. This research investigated the early establishment of hybrid sorghum under three seeding strategies, ”Uniformise” (medium density across all zones), “Optimise” (increased density in low-soil apparent Electrical Conductivity (ECa)), and “Maximise” (increased density in high-soil ECa), at the Herdade da Comenda (Innovation Center—Elvas, Portugal). Crop performance was monitored over 33 days, the established window for safe direct grazing, using Unmanned Aerial Vehicle (UAV) multispectral imagery to derive the Normalised Difference Vegetation Index (NDVI) and Canopy Cover (Cveg), alongside physical sampling of plant height and biomass. Statistical analysis revealed that both the seeding strategy and soil variability significantly affected early growth. The “Uniformise” strategy recorded the highest plant height, NDVI, and Cveg values, whereas the “Optimise” strategy performed the poorest. Additionally, an accumulation of 407.5 Growing Degree-Days (GDDs; °C) accelerated the phenological cycle by five days relative to the climatological normal. Despite differences in vegetative vigour, no statistically significant variations were observed in final biomass across the strategies. These results indicate that while the “Uniformise” approach provided a more balanced environment for early establishment under these specific Mediterranean conditions, the lack of biomass differentiation highlights the potential for resource optimisation. The study demonstrates that UAV-based remote sensing is a useful diagnostic tool to identify these spatial limitations, providing the data to refine variable-rate seeding (VRS) algorithms and improve the economic efficiency of precision sowing.

Grasses doi: 10.3390/grasses5010011

Authors: Florencia Arroyo Mauro Martínez Agustín Arata Marie Dufresne Sebastián Stenglein María Inés Dinolfo

Brachypodium distachyon has become a widely studied model plant due to its small genome, ease of cultivation under controlled conditions, and value for synteny and molecular studies. Regarding disease, Fusarium is one of the main fungal genera infecting cereal crops, F. cerealis, F. graminearum, F. poae, and F. pseudograminearum being isolated frequently from several agricultural regions. Therefore, the present study aimed to evaluate three pathosystems, combining three hosts (B. distachyon, barley, and wheat) with four Fusarium species to confirm the use of B. distachyon in Fusarium–crop system models. Three controlled experiments were performed to assess the impact on seeds, roots, and spikes. Variables such as germination inhibition, McKinney’s index, percentage of necrosis, area under the disease progress curve, disease incidence, disease severity, and grain weight were measured. Regarding Fusarium species, the results confirm that F. pseudograminearum could be more aggressive on roots, while F. graminearum affects spikes more severely. In contrast, F. cerealis and F. poae are generally moderate to weak pathogens with irregular behaviour depending on the plant species or genotype. No clear varietal resistance pattern emerged except for wheat genotypes with a known resistance/susceptibility QTL. The present study highlights the importance of using multiple experiments for accurate phenotype characterisation, as relying on a single technique is insufficient. In conclusion, the results presented in the manuscript provide valuable insights into Fusarium spp.–B. distachyon interactions and resistance selection based on seed, root, and spike assessments. Moreover, this work confirmed the use of Brachypodium as a model plant for Fusarium–plant interaction studies.

Grasses doi: 10.3390/grasses5010010

Authors: Larry Niño Orlando Rangel Diego Giraldo-Cañas Daniel Sánchez-Mata Vladimir Minorta-Cely

This study presents a high-resolution mapping of grassland phytosociological alliances in the Colombian Orinoquia by integrating multi-source remote sensing data (Landsat-8 optical and Sentinel-1 SAR) with environmental variables within a Random Forest classification framework. Based on 292 rigorously classified vegetation plots, we modeled the distribution of 18 alliances across dominant geomorphological units: the alluvial plain (north) and the high plain (south-central). Results demonstrate that natural vegetation covers 73.74% of the region, with grasslands (41.55%) representing a more extensive formation than forests (32.19%). The alliances Paspalo pectinati–Axonopodion aurei (6.02%) and Axonopodo aurei–Trachypogonion spicati (4.37%) were identified as the most widespread. Ecological analysis revealed a pronounced dominance of C4 Poaceae species, particularly in alliances such as Sipaneo pratensis–Axonopodion purpusi (60% C4 diagnostic species), reflecting adaptations to seasonal moisture stress and high irradiance. Our methodology demonstrates that coupling phytosociological field data with multi-sensor remote sensing achieves high classification accuracy (79–87%), providing a robust tool for moving beyond descriptive vegetation mapping toward a comprehensive understanding of grassland distribution patterns at regional scales.

Grasses doi: 10.3390/grasses5010009

Authors: Yuting Jin Changbin Li Tongtong Deng Jie Hu Xilai Li Yuanwu Yang

The degradation of alpine meadows on the Qinghai–Tibet Plateau has seriously affected the structure and productivity of grassland communities. In this experiment, a sample area was set up in Keqihetan of Zexiong Village, Youganning Town, Henan County, Mongolian Autonomous Prefecture. The degraded alpine meadow was divided into three plaque types, bare patches (BP), short-term recovered patches (SRP), and long-term recovered patches (LRP), and Native alpine meadows (NM) as controls, in order to reveal the effects of grassland degradation on community structure and aboveground/belowground biomass allocation in alpine meadow. Here, we measured total biomass (TCB), aboveground biomass (AGB), belowground biomass (BGB), and root/shoot ratio (R/S) of alpine meadows on the Qinghai–Tibetan Plateau and investigated plant community cover and height. The results showed that with the restoration of the patchy alpine meadow, the height decreased first and then increased, the amount of AGB increased first and then decreased, while the coverage and BGB increased in turn, and BGB decreased with the deepening of soil depth. We also found that R/S decreased first and then increased with the patch recovery of the alpine meadow. The overall distribution of AGB and BGB belongs to allometric growth distribution, but the native meadow belongs to isometric growth distribution, while other recovery stages belong to allometric growth distribution. By studying the biomass and its distribution of degraded grassland, we can understand the impact of grassland degradation on the community structure and productivity of the alpine meadow.

Grasses doi: 10.3390/grasses5010008

Authors: Renata Franciéli Moraes Daniela Maria Martin Arthur Pontes Prates Carolina Bremm Paulo Cesar de Faccio Carvalho Lucas Aquino Alves Leandro Bittencourt de Oliveira Anibal de Moraes

Sward height is a practical indicator for defining management targets that reflect pasture structure. The complexity of integrated systems, including the coexistence of trees, crops, and livestock, can modify animal grazing distribution and microhabitat conditions, leading to different degrees of sward heterogeneity and botanical composition. This study investigated sward-height distribution and species composition in four systems: livestock (L), livestock–forestry (LF), crop–livestock (CL), and crop–livestock–forestry (CLF). Data were collected over two years in pastures of black oat (Avena strigosa Schreb.), Aries grass (Megathyrsus maximus cv. Aries), Italian ryegrass (Lolium multiflorum Lam.), and other tropical grasses during summer, transition, and winter. Sward heights were classified into three categories (low, optimal, high) according to seasonal thresholds (winter: <18.0; 18–29.9; >30 cm; summer: <15.0; 15–24.9; >25 cm) and fitted to four probability distributions (normal, log-normal, Gamma, Weibull). Management based on target-height maintained 46% of observations within the optimal class, a satisfactory proportion for continuous stocking systems where structural heterogeneity is inherent. The CL system presented greater species diversity due to a higher frequency of Italian ryegrass and other grasses. Across systems and seasons, the Gamma distribution provided the best fit for sward-height frequencies. These findings offer a practical statistical tool for evaluating grazing management efficiency.

Grasses doi: 10.3390/grasses5010007

Authors: Diego D. Bianchi Trevor R. Hodkinson

There is an urgent demand for sustainable agricultural practices that minimize environmental impacts and reduce the reliance on synthetic pesticides and fertilizers. Endophytes represent a largely untapped resource of beneficial microorganisms with multiple potential applications as natural biocontrol agents and promoters of plant growth and development. This paper aimed at identifying new fungal strains and performing a series of preliminary in vitro screenings to evaluate their potential use for plant-growth promotion and antifungal activity. A total of 102 fungal endophytes were isolated from different plant tissues of seven wild relatives of barley (Brachypodium sylvaticum, Bromus hordeaceus, Bromus sterilis, Elymus farctus, Elymus repens, Leymus arenarius and Lolium perenne) that were sourced from 22 contrasting wild habitats. Fungal endophytes were isolated using standard culture-based methods and identified via DNA barcoding of the nrITS marker. Based on a literature search, a sub-group of endophytes were selected and evaluated for indole-3-acetic acid (IAA) synthesis, ammonia production and phosphorous (P) solubilization. From these, 15 endophytes were also tested for antifungal activity against Ramularia collo-cygni, Pyrenophora teres, and Gaeumannomyces tritici. All the endophytes were positive for ammonia production at variable rates, but no P solubilization nor IAA synthesis without L-tryptophan were observed. On the contrary, five promising isolates (2 Daldinia concentrica, Metapochonia suchlasporia, Chaetomium sp., and Ophiocordyceps sinensis) had mean pathogen growth inhibition rates above 80%, compared to the untreated negative controls. To the best of our knowledge, this study is the first published report that investigates natural antagonism against Ramularia collo-cygni and expands the list of endophytic strains with natural antagonism on the tested cereal pathogens. Results are discussed in the context of endophytes application to barley cultivation within the European regulatory framework.

Grasses doi: 10.3390/grasses5010006

Authors: Hugo López Rosas Patricia Moreno-Casasola

African grasses deliberately introduced for cattle forage have become among the most destructive invaders of tropical wetlands globally, yet invasion mechanisms and management strategies remain poorly understood. We conducted field experiments examining competition dynamics between the invasive African grass Echinochloa pyramidalis and native wetland species in La Mancha, Mexico—a Ramsar site of international importance. Experiment 1 tested invasion potential within native Sagittaria lancifolia zones using four treatments: control, herbicide removal, E. pyramidalis transplant, and combined removal + transplant. Repeated-measures ANOVA showed significant treatment and time effects on invasion success, with vegetation removal facilitating invasion (relative importance value increasing from 0 to 149.4 ± 26.6 after 18 months) while transplants alone failed to establish (RIV < 7.0). Sagittaria maintained 35–48% biomass across treatments, demonstrating coexistence capacity. Experiment 2 examined natural invasion of the vegetation ecotone over 49 months. Mixed-effects models revealed that E. pyramidalis increased dominance in its zone (β = 9.98, z = 4.77, p < 0.001) but showed minimal expansion into the adjacent Sagittaria habitat, indicating propagule limitation rather than competitive exclusion as the invasion constraint. Sagittaria removal within E. pyramidalis zones significantly reduced invasion temporal increase (β = −6.44, z = −2.18, p = 0.030), suggesting biotic resistance. Results demonstrate that E. pyramidalis possesses invasion potential but requires disturbance to overcome establishment barriers. These findings support prevention-based management prioritizing disturbance limitation in intact wetlands and demonstrate that hydrological management maintaining permanent flooding (>30 cm depth) can effectively control established invasions by exploiting C4 photosynthetic limitations. Conservation implications for Mexican coastal wetlands—which lack legal protection equivalent to mangroves despite comparable ecosystem services—are discussed. These findings inform evidence-based management of African grass invasions in tropical wetlands worldwide.

Grasses doi: 10.3390/grasses5010005

Authors: Clemeson Silva de Souza Marcio de Oliveira Martins Liana Jank Sanzio Carvalho Lima Barrios Carlos Mauricio Soares de Andrade Márcia Silva de Mendonça Giselle Mariano Lessa de Assis

Poorly drained pastures in tropical America are recurrently degraded by Marandu Death Syndrome (MDS), affecting beef and dairy production. This study screened genotypes of Megathyrsus maximus and Urochloa spp. for waterlogging tolerance under controlled conditions to identify discriminant, easily measurable morphoagronomic traits suitable for breeding programs. Four experiments were conducted in factorial arrangement (five genotypes × two water regimes, with four replications), where morphoagronomic and physiological variables were analyzed using multivariate techniques. The first two principal components explained 75.17–88.60% of the total variation and stayed above 70% after variable reduction, without significantly altering genotype dispersion. Physiological responses showed a strong correlation with morphoagronomic traits. The most informative traits were the number of yellow and senescent leaves, number of tillers, SPAD index, leaf dry mass, and root dry mass. Genotypes were grouped by tolerance level. Among M. maximus, ‘Mombaça’ was the most tolerant, while PM13 and PM21 were the least. In Urochloa spp., U. humidicola cv. Tully was the most tolerant and ‘Marandu’ the least tolerant. Screening under controlled conditions is an alternative to distinguish genotypes with contrasting tolerance; however, because controlled environments do not fully reproduce the multifactorial nature of MDS, this approach is recommended only for early stages of breeding programs. Nevertheless, field evaluations on poorly drained soils under grazing remain essential to confirm tolerance to MDS.

Grasses doi: 10.3390/grasses5010004

Authors: Alessandra Rodrigues Kozovits Maurílio Assis Figueiredo Maria Cristina Teixeira Braga Messias

The Campos Rupestres, ancient and nutrient-poor mountaintop ecosystems in Brazil, harbor exceptional biodiversity and endemism but face severe threats from mining and urban expansion. Native grasses (Poaceae), represented by nearly 300 documented species—many of them poorly studied—are fundamental elements of these ecosystems. They provide critical ecological services, including soil stabilization, enhancing carbon storage and nutrient cycling, regulating water availability, and resilience to disturbances. This review synthesizes current knowledge on the diversity, functions, and propagation of Campos Rupestres grasses, with emphasis on their potential in ecological restoration. Despite their ecological importance, large-scale use of native grasses remains incipient, constrained by limited knowledge of reproductive biology, low seed viability, and scarce commercial seed availability. Advances in propagation include seedling and plug production, vegetative propagation, and rescue/reintroduction strategies, which have shown promising results in post-mining restoration. However, reliance on seed collection from natural populations risks depleting already limited genetic resources, highlighting the need for ex situ production systems. Expanding research on taxonomy, ecology, and cost-effective propagation methods, alongside supportive policy and market development, is crucial for integrating native grasses as cornerstone species in restoration programs. Bridging these gaps will enhance biodiversity conservation and restoration in one of the world’s most threatened megadiverse systems.

Grasses doi: 10.3390/grasses5010003

Authors: Andis Karlsons Anita Osvalde Una Andersone-Ozola Astra Jēkabsone Gederts Ievinsh

Functional properties of coastal halophytes are important for development of salt-tolerant cash crop cultures. The study of salt tolerance in coastal dune-building grass Leymus arenarius holds significant importance for its application in land reclamation, soil stabilization, and enhancing crop resilience to salinity stress. We used two accessions (LA1 and LA2) of L. arenarius to compare effects of salinity caused by NaCl and NaNO3 on growth, ion accumulation and mineral nutrition in controlled conditions. L. arenarius plants exhibited high tolerance to sodium salts, with distinct effects on growth and development observed between chloride and nitrate treatments. While both salts negatively impacted root biomass, nitrate treatment (50–100 mmol L−1) increased leaf number and biomass in LA2 plants, whereas chloride treatment decreased tiller and leaf sheath biomass. Despite individual variations, salinity treatments showed comparable effects on traits like tiller and leaf count, as well as leaf blade and sheath biomass. Salinity increased water content in leaf blades, sheaths, and roots, with LA2 plants showing the most pronounced effects. Chlorophyll a fluorescence measurements indicated a positive impact of NaNO3 treatment on photosynthesis at intermediate salt concentrations, but a decrease at high salinity, particularly in LA2 plants. The accumulation capacity for Na+ in nitrate-treated plants reached 30 and 20 g kg−1 in leaves and roots, respectively. In contrast, the accumulation capacity in chloride-treated plants was significantly lower, approximately 10 g kg−1, in both leaves and roots. Both treatments increased nitrogen, phosphorus, and manganese concentrations in leaves and roots, with varying effects on calcium, magnesium, iron, zinc, and copper concentrations depending on the type of salt and tissue. These findings highlight the potential of L. arenarius for restoring saline and nitrogen-contaminated environments and position it as a valuable model for advancing research on salt tolerance mechanisms to improve cereal crop resilience.

Grasses doi: 10.3390/grasses5010002

Authors: Ma. Enriqueta Luna-Coronel Héctor Gutiérrez-Bañuelos Daniel García-Cervantes Alejandro Espinoza-Canales Luis Cuauhtémoc Muñóz-Salas Francisco Javier Gutiérrez-Piña

Grassland-based livestock systems across Mexico’s arid and semi-arid belt are increasingly exposed to drought, degrading forage reliability, and soil function. This review synthesizes evidence on native C4 grasses and forage shrubs as complementary building blocks of drought-resilient swards. We searched Web of Science, Scopus, CAB Abstracts and key grey sources (USDA/NRCS Plant Guides, USFS FEIS, Tropical Forages, SNICS) for 1990–2025 studies in English/Spanish. Dominant native grasses (Bouteloua spp., Hilaria belangeri, Digitaria californica, Trichloris crinita, Sporobolus airoides, Panicum hallii) provide high warm-season digestibility and structural cover via C4 physiology, basal/intercalary meristems, and deep/fibrous roots. Forage shrubs (Atriplex canescens, Desmanthus bicornutus, Leucaena leucocephala, Flourensia cernua, Prosopis spp.) bridge the dry-season protein/energy gap and create “resource islands” that enhance infiltration, provided anti-nutritional risks (mimosine/DHP, tannins, salts/oxalates, terpenoids) are managed by dose and diet mixing. We integrate these findings into a Resistance–Recovery–Persistence framework and translate them into operations: (i) site-matching rules for species/layouts, (ii) PLS (pure live seed)-based seed specifications and establishment protocols, (iii) grazing TIDD (timing–intensity–distribution–duration) with a practical monitoring dashboard (CP targets, stubble/cover thresholds, NDVI/SPEI triggers). Remaining bottlenecks are seed quality/availability and uneven extension; policy alignment on PLS procurement and regional seed increase can accelerate adoption. Mixed native grass–shrub systems are a viable, scalable pathway to strengthening drought resilience in Mexican rangelands.

Grasses doi: 10.3390/grasses5010001

Authors: Matheus Silva Rodrigues Hemython Luis Bandeira do Nascimento Darliane de Castro Santos Bárbara Vieira de Freitas Victória Caroline Sousa Rosa Tiago do Prado Paim Jaqueline Balbina Gomes Ferreira Stéfany Oliveira de Souza Victória Santos Souza Patrick Bezerra Fernandes

In the oilseed–cereal–forage system, information on the performance of grasses of the genus Megathyrsus maximus and on the optimal fertilization levels for forage production is still scarce. Therefore, this study aimed to evaluate forage yield (FY) of pastures established in crop succession systems and subjected to two fertilization regimes during the 2020 and 2021 growing seasons, in the municipality of Rio Verde, Brazil. The experiment evaluated four M. maximus cultivars (Paredão, Zuri, Quênia, and Tamani) under two fertilization rates: maintenance (50, 50, 20, and 3.2 kg ha−1 year−1 of N, K, S, and micronutrients, respectively) and enhanced (150, 150, 40, and 6.4 kg ha−1 year−1, respectively). The Zuri cultivar showed a higher daily forage accumulation rate and greater forage leaf mass compared with the other cultivars. In addition, the Zuri and Paredão cultivars achieved the highest FY, reaching 12.80 and 12.10 Mg ha−1, respectively. The Tamani cultivar exhibited a lower neutral detergent fiber concentration and a higher total digestible nutrient concentration, indicating its potential for systems that prioritize higher forage nutritive value. Zuri and Paredão maximize forage yield in crop succession systems, while enhanced fertilization increases yield by 15%, with adoption dependent on economic feasibility.

Grasses doi: 10.3390/grasses4040053

Authors: Mica McMillan Kimberly Moore Marco Schiavon Lyn Gettys John Cisar Karen Williams

Nitrogen (N) uptake of managed turfgrasses in sand rootzones is of particular importance as it relates to reducing N leaching, reducing or maximizing N fertilizer applications, and optimizing overall plant quality. Two greenhouse experiments were conducted to determine if the inclusion of a one-time application of soil surfactant tank-mixed with ammonium sulfate fertilizer (FERT) improved fertilizer longevity and bermudagrass (Cynodon dactylon L. Pers. × C. transvaalensis Burtt-Davy, cv. ‘TifEagle’) quality (TQ), yield, leaf N content, N uptake (NUP), chlorophyll index (CI), and volumetric water content (VWC) under deficit irrigation. An untreated, fertilizer-only (Fert) (49 kg N·ha−1), and non-ionic alkylpolyglycoside/ethylene oxide-propylene oxide (AEP) was tank-mixed with fertilizer at two rates, Fert+AEP(L) (1.17 L·ha−1) or Fert+AEP(H) (1.75 L·ha−1), to determine rate efficacy. In 2015, Fert and Fert+AEP(L) significantly increased TQ and CI, while in 2016, both AEP (L and H) significantly increased only TQ. VWC was significantly greater in untreated in 2015. At the end of the trials in 2015 and 2016, yield and NUP were significantly greater in Fert+AEP(H) and Fert+AEP(L), respectively, but leaf N content was not statistically significant between all fertilizer treatments. The role of surfactants in prolonging fertilizer effectiveness under deficit irrigation warrants further investigation.

Grasses doi: 10.3390/grasses4040052

Authors: Ousmane Diatta Torbern Tagesson Ousmane Ndiaye Mohamed Badji Simon Taugourdeau

Savanna ecosystems of the Sahel are heavily affected by climate change, leading to drier subtropical regions. These ecosystems play a fundamental role in food security of the region, so that an improved understanding of how these ecosystems are affected by these weather events is thereby critical. Several studies have assessed the herbaceous production level, dynamics during the rainy season, and biotic and abiotic factors that could impact this production. Some authors argue that rain is the main factor positively influencing the biomass production in semi-arid areas where the rainfall ranges between 200 and 750 mm. This study aims to assess the contribution of some meteorological variables to biomass production in a Sahelian semiarid savannah. From 2008 to 2018, rainfall (mm), soil moisture (%), soil temperature (°C) at 5 cm depth, number of times there was no rain (NTNR), number of rainy days, and the herbaceous biomass were monitored. The contributions of meteorological variables to biomass production were calculated using the XGBoost regression model. The most influential meteorological parameters on herbaceous biomass production are soil temperature, amount, and distribution of rainfall.

Grasses doi: 10.3390/grasses4040051

Authors: Luis Ángel Barrera-Guzmán Juan Guillermo Cruz-Castillo Juan Ángel Tinoco-Rueda Héctor Tecumshé Mojica-Zárate Jorge Cadena-Iñiguez Gabriela Ramírez-Ojeda Jhusua David Reina-García Juan Miguel Morales-Téllez

Bidens pilosa L. is a cosmopolitan and invasive weed that strongly impacts agricultural systems in tropical regions. In Veracruz, Mexico, its presence extends mainly across mid-elevation zones where coffee, maize, and sugarcane are cultivated. This study characterized the bioclimatic and edaphic determinants of B. pilosa distribution using 581 georeferenced occurrences combined with 19 bioclimatic variables, elevation, and soil data. A Maxent model revealed the highest habitat suitability (0.65–1.0) in the central mountainous region between 800 and 1500 m.a.s.l., particularly under temperate–humid climates (Cfa, Cfb) and Acrisol–Leptosol soils. Principal component and redundancy analyses showed that annual precipitation (BIO12), precipitation of the driest month (BIO14), and temperature seasonality (BIO4) explained 74.7% of the total environmental variance. Cluster analysis identified four distinct ecological groups, confirming broad ecological plasticity. These findings indicate that B. pilosa is not randomly distributed but structured along climatic and soil gradients, with precipitation and elevation as major determinants of its ecological niche. Understanding these relationships provides a quantitative framework for predicting its expansion under future climate scenarios and for designing targeted management strategies in tropical agroecosystems.

Grasses doi: 10.3390/grasses4040050

Authors: Fernando Oliveira Bueno Santiago Vianna Cuadra Monique Pires Gravina de Oliveira Fabiani Denise Bender José Ricardo Macedo Pezzopane Patricia Menezes Santos Sandra Furlan Nogueira Luciana Gerdes Flavia Maria de Andrade Gimenes

The use of plant growth simulation models, such as the Agricultural Crop Simulator (AgS), can support planning and management decisions in pasture-based animal production systems. AgS is a biophysical model that is being developed to focus on crops relevant to the Brazilian economy. Originally, the model was parameterized for Marandu palisadegrass (Urochloa brizantha cv. Marandu) under continuous stocking method and cutting regimes. The objective of this study was to parametrize and evaluate the performance of AgS in simulating Marandu palisadegrass biomass production under rotational stocking methods. Field data from an experiment assessing pre-grazing heights of Marandu palisadegrass grazed by beef cattle was used to evaluate the model. The simulations initially underestimated leaf and total biomass production, regardless of pre-grazing height. These results suggested that differences between cutting and grazing methods make additional model calibration necessary. Differences related to regrowth of leaves were addressed and the new calibration resulted in higher biomass allocation to leaves and stems, reducing the mean error in the 25 cm treatment from −1.001 to −253 kg ha−1 and the rRMSE from 41% to 34%. AgS showed potential for simulating rotational stocking after adjustments were made, and future calibrations should consider different management and environmental conditions.

Grasses doi: 10.3390/grasses4040049

Authors: Haishan Niu Tsechoe Dorji Shiping Wang

Numerous studies indicate that the Tibet Autonomous Region’s grasslands have experienced widespread greening since remote sensing data became available. While climate warming and moistening can drive this trend, there is growing interest in quantifying the effect of non-climatic factors, including human activities. A widely used method estimates these effects by comparing potential and actual vegetation productivity. This study focuses on Ngari, a region constrained by both temperature and moisture. We constructed a multiple regression model using climate variables to predict NDVI and to achieve a good fit for as many pixels as possible. Residual trends, analyzed via the Kendall Tau method, reflect vegetation dynamics after removing climatic effects—a form of statistical control. Results show that grassland NDVI in Ngari increased overall (2000–2024), with 73% of pixels showing a positive Kendall Tau (among them 34% were significant at p < 0.05). The best-performing model used July–August SPEI, April–July precipitation, and mean temperature. After removing climate effects, pixels with a positive Kendall Tau rose to 74.1% (among them 21% were significant at p < 0.05), indicating that non-climatic factors exerted a net positive influence on Ngari’s grassland trends from 2000 to 2024.

Grasses doi: 10.3390/grasses4040048

Authors: Elisiane Alba José Edson Florentino de Morais Wendel Vanderley Torres dos Santos Josefa Edinete de Sousa Silva Denizard Oresca Luciana Sandra Bastos de Souza Alan Cezar Bezerra Emanuel Araújo Silva Thieres George Freire da Silva Jose Raliuson Inacio Silva

This study aimed to assess the potential of machine learning models applied to high spatial resolution images from UAVs for estimating the aboveground biomass (AGB) of forage grass cultivated in the Brazilian semiarid region. The fresh and dry AGB were determined in Cenchrus ciliare plots with an area of 0.04 m2. Spectral data were obtained using a multispectral sensor (Red, Green, and NIR) mounted on a UAV, from which 45 vegetation indices were derived, in addition to a structural variable representing plant height (H95). Among these, H95, GDVI, GSAVI2, GSAVI, GOSAVI, GRDVI, and CTVI exhibited the strongest correlations with biomass. Following multicollinearity analysis, eight variables (R, G, NIR, H95, CVI, MCARI, RGR, and Norm G) were selected to train Random Forest (RF), Support Vector Machine (SVM), and XGBoost models. RF and XGBoost yielded the highest predictive performance, both achieving an R2 of 0.80 for AGB—Fresh. Their superiority was maintained for AGB—Dry estimation, with R2 values of 0.69 for XGBoost and 0.67 for RF. Although SVM produced higher estimation errors, it showed a satisfactory ability to capture variability, including extreme values. In modeling, the incorporation of plant height, combined with spectral data obtained from high spatial resolution imagery, makes AGB estimation models more reliable. The findings highlight the feasibility of integrating UAV-based remote sensing and machine learning algorithms for non-destructive biomass estimation in forage systems, with promising applications in pasture monitoring and agricultural land management in semi-arid environments.

Grasses doi: 10.3390/grasses4040047

Authors: Christopher T. Beard William S. Swecker Ozzie Abaye Gabriel J. Pent

Achieving satisfactory levels of weight gain for developing replacement beef heifers is challenging when utilizing toxic endophyte-infected tall fescue (Schedonorus arundinaceus) as the primary forage. This is due to the intensifying impact of ergot alkaloids produced by the fungal endophyte on heifer heat stress in the summer. The purpose of this trial was to determine if clipping hair coats would reduce heat stress impacts experienced by fall-born heifers stocked on toxic endophyte-infected tall fescue. Heifers were randomly assigned to a control cohort and a clipped cohort. The heifers in the clipped treatment group were sheared along the body of the heifer. Vaginal temperature loggers were used to record core temperatures every ten minutes during several sampling periods. Hair coats on clipped heifers resembled hair coats of the control heifers by the conclusion of the 16-week trial. Average daily gains of the clipped heifers exceeded the average daily gains of the control heifers only in the first four-week period. There were no differences in seasonal average daily gain or pregnancy rates. Clipped heifers had cooler core temperatures by 0.2–0.3 °C in the morning compared to the control heifers. Clipping hair coats of heifers only provided short-term relief for cattle stocked on toxic endophyte-infected tall fescue.

Grasses doi: 10.3390/grasses4040046

Authors: Damian A. Ravetta Alejandra Vilela Lee DeHaan Luciana González Paleo

Thinopyrum intermedium (c.n. intermediate wheatgrass), marketed under the trade name Kernza, is a promising species for perennial grain production based on seed size, ease of threshing, resistance to shattering, and grain quality. Although numerous generations of breeding for seed yield have been completed, the impact of selection on non-target traits is unknown. Here, we evaluated structural and functional changes brought about by selection for seed yield over a sequence of nine selection cycles (C0 to C9). In two experiments under semi-controlled environmental conditions, we compared gas exchange (A, E, gs, and A/Ci curves), leaf and root morphology, and the structure of seedlings from 10 generations. We found that the selection for yield throughout cycles indirectly changed the leaf structure (leaf size, leaf thickness, and leaf anatomy) and physiology (carbon acquisition and transpiration per unit area), with later cycles showing larger leaves with higher rates of CO2 assimilation and transpiration. Changes in root structure followed similar trends: selection resulted in longer, more branched, and finer roots. These changes in non-target traits are linked to resource-use strategies and to ecosystem services provided by Kernza. Understanding how the domestication of perennial grains impacts non-target traits will aid in the design of integrated breeding programs for Kernza and other perennial grain crops.

Grasses doi: 10.3390/grasses4040045

Authors: Tersur T. Akpensuen Nenken E. Pyalson Andrew S. Cooke Michael R. F. Lee M. Jordana Rivero

The yield and quality of biomass produced in a growing season determine feed allocation, livestock performance, and system capacity and resilience. Congo grass (Urochloa ruziziensis, UR) and Rhodes grass (Chloris gayana, CG) are important grass species for livestock in Sub-Saharan Africa, where their high yield potential and adaptability provide leverage to mitigate persistent feed gaps. This study investigated the morphological traits, biomass yield, and nutritive value of UR and CG in the Northern Guinea Savanna of Nigeria over three years (2019–2021) to assess their biomass yield and quality responses to successive harvests. We hypothesised that UR would outperform CG in yield and quality over the study period. Grasses were established in 2019, with multiple harvests annually from four replicate plots per species. UR consistently produced more tillers and leaves per tussock and achieved significantly higher biomass and crude protein (CP) yields at each harvest (p < 0.001), averaging 32.2% and 38.4% greater biomass and CP, respectively, compared to CG. Nutritional analysis revealed that CG contained 19.4% less CP, 23.4% less metabolisable energy, and 22.7% less ash than UR, while having higher fibre fractions (p < 0.001). Overall, UR demonstrated superior productivity and nutritional value under the tested conditions, highlighting its potential as a more reliable forage option for farmers in the Northern Guinea Savanna of Nigeria.

Grasses doi: 10.3390/grasses4040044

Authors: Carlos Eduardo Lazarini da Fonseca Marcelo Ayres Carvalho Marco Pessoa-Filho Allan Kardec Braga Ramos Cláudio Takao Karia Gustavo José Braga Natália Bortoleto Athayde Maciel Suelen Nogueira Dessaune Tameirão

Gamba grass (Andropogon gayanus Kunth) is a promising forage alternative for Brazil’s Cerrado regions, attracting increasing research interest due to its potential to complement or replace widely planted species such as Urochloa and Megathyrsus. Despite the release of three cultivars, significant improvements in dry matter (DM) yield and forage quality are needed to fully realize its agronomic potential. This study aimed to evaluate genetic variability, estimate narrow sense heritability, and predict expected genetic gains for DM yield and key forage quality traits in two gamba grass populations derived from the cultivars BRS Sarandi and Planaltina. Trials were established in spring 2017 in Planaltina, DF, and evaluated during February–March 2018 and January–March 2019. Crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose (CEL), and hemicellulose (HEMIC) were quantified alongside DM yield. BRS Sarandi exhibited higher CP (12.3% vs. 9.8%) and lower NDF (57.1% vs. 63.4%), ADF (36.2% vs. 41.5%), CEL (20.8% vs. 23.7%), and HEMIC (20.9% vs. 21.9%) compared to Planaltina, while DM yield did not differ significantly between populations (4.57 t·ha−1 vs. 4.50 t·ha−1 per harvest, p > 0.05). Heritability estimates for individual harvests ranged from 0.31 to 0.68 for DM yield and 0.28 to 0.62 for quality traits, whereas multi-harvest models across years yielded lower estimates (0.07–0.27). Expected annual genetic gains were modest, with the highest predicted increase for CP (0.45% per year) and the largest decrease for NDF (−0.78% per year), reflecting the quantitative nature of trait inheritance and strong environmental influence. This study provides novel insights by simultaneously comparing two populations for multiple harvests and quantifying both yield and detailed forage quality traits, offering practical guidance for gamba grass breeding strategies. Results indicate that breeding programs should prioritize multiple selection cycles, precise phenotyping, genotypic and potentially genomic selection to accelerate improvement in both DM yield and forage quality, overcoming the constraints of low heritability and multi-trait selection.

Grasses doi: 10.3390/grasses4040043

Authors: Wagner Sousa Alves Albert José dos Anjos Danielle Nascimento Coutinho Paulo Fortes Neto Tamara Chagas da Silveira Karina Guimarães Ribeiro

Although pastures cover nearly half of Brazil’s agricultural land and form the backbone of national livestock production, they have historically received limited attention regarding management and fertilization, resulting in widespread degradation. Sustainable intensification of these pasture-based systems is therefore essential to meet growing global demand for animal products while minimizing environmental impacts. This review highlights recent technological innovations in pasture fertilization in Brazil, with a particular focus on alternative phosphorus sources such as natural reactive phosphates, which offer slow-release nutrients at lower costs compared to conventional fertilizers. Efforts to enhance nitrogen use efficiency through nitrification and urease inhibitors show promise in reducing nutrient losses and greenhouse gas emissions, despite current cost constraints limiting adoption. The integration of grass-legume intercropping, especially with Arachis pintoi, has been shown to enhance forage quality and system persistence when appropriately managed. Moreover, plant growth-promoting microorganisms emerge as sustainable biotechnological tools for restoring degraded pastures and boosting forage productivity without adverse environmental consequences. Properly treated agro-industrial residues also present a viable nutrient source for pastures, provided environmental regulations are strictly followed to prevent pollution. Together, these innovations offer a comprehensive framework for enhancing the productivity and sustainability of Brazilian livestock systems, highlighting the pressing need for continued research and the adoption of advanced fertilization strategies.

Grasses doi: 10.3390/grasses4040042

Authors: John Dempsey Michael Fidanza Stanley Kostka

Soil surfactants are essential tools for enhancing irrigation water efficiency and improving the quality and functionality of amenity turfgrass. They play a crucial role in sports turf management by reducing soil water repellency, which helps prevent dry spots, ensures even moisture distribution, and supports water conservation efforts. Most research on soil surfactants and amenity turfgrasses focuses on their effects on soil moisture, infiltration, and addressing localized dry spots during drought conditions, with limited studies on their impact under wet or saturated conditions. This study aimed to evaluate the impact of soil surfactants on the quality and health of turfgrass under wet conditions. Field studies were conducted over a span of five years, beginning in the USA in 2019 and continuing in Ireland from 2020 to 2023. The research in Ireland was conducted at three locations, each featuring different rootzones: a “push-up” green with loam soil, USGA-specification sand, and natural link sand. The site in the USA was a native loam soil. The study compared a commercial soil surfactant (ProWet Evolve; PWE) and a non-treated control (NT) in a randomized complete block design with four replications, with sequential applications starting in June and continuing until mid-September each year. The rootzone volumetric water content (VWC%), turfgrass quality, and normalized difference vegetation index (NDVI) were measured bi-weekly. Environmental conditions, with above-average precipitation each year, significantly influenced results. Although there were no significant or consistent differences in VWC% between the soil surfactant and NT-treated plots, turfgrass quality was significantly enhanced in the soil surfactant-treated plots and supported by higher NDVI values. Even in prolonged wet conditions with high VWC%, improved turfgrass quality was consistently observed in soil surfactant-treated plots across multiple locations in both countries over the five-year study period.

Grasses doi: 10.3390/grasses4040041

Authors: Giuliano Sciusco Simone Magni Samuele Desii Nicolò Colombini Marco Fontanelli Tommaso Federighi Marco Volterrani

High-quality playing surfaces enhance player experience and safety while serving as an appealing setting for spectators. Natural turfgrass provides optimal conditions at the beginning of the playing season but faces challenges under increasing field usage. Turfgrasses with high wear tolerance and quick recovery capacity are crucial for maintaining surface quality under intensive wear. Bermudagrass is the most used species in warm climates but needs winter overseeding in the transition zone. In Mediterranean climates, tall fescue (Schedonorus arundinaceus (Schreb.) Dumort, formerly Festuca arundinacea) has emerged as a promising species due to its tolerance to heat, drought, and salinity, alongside traits like deep rooting, shade adaptation, and wear resistance. The trial was conducted at the CeRTES experimental station in Rottaia, Pisa, Italy. Twenty-seven tall fescue cultivars and three cultivars of perennial ryegrass (Lolium perenne L.) were hand-seeded on 3 November 2022, at a rate of 43 g m−2. The experimental design consisted of plots measuring 4.5 m2 arranged in a randomized complete block design with three replications. The objective of the study is to evaluate the performance of twenty-seven cultivars of tall fescue with the aim of using the species in soccer fields with a permanent stand approach, with no need to manage spring and fall transitions. The field study encompasses determinations referring to the establishment stage, the maintenance at low cutting height stage (20 mm) and the subsequent stage of soccer use under different seasonal conditions (autumn, winter, and spring). Results showed that certain fescue cultivars, notably ‘Essential’, ‘Eyecandy’, and ‘FAG3/19-20208B’, exhibited quick establishment and adaptation to low cutting height (20 mm), and performed similarly to the reference ryegrasses ‘Gianna’ and ‘Mercitwo’ in terms of wear tolerance and recovery capacity across the three seasons. Moreover, most of the tested tall fescue cultivars performed well at a 20 mm mowing height, maintaining satisfactory quality and density. Among these, ‘Eyecandy’ and ‘Foxhound’ displayed finer leaf textures, comparable to those of the reference ryegrass.

Grasses doi: 10.3390/grasses4040040

Authors: Florencia Marcón Elio L. Di Lorenzo Myriam C. Peichoto Carlos A. Acuña

Warm-season grasses are the main source of feed in tropical and subtropical beef cattle production systems. The objective was to assess cattle preference among three warm-season grasses and explore its relationship with forage yield and plant structural traits. The three species were cultivated in 2 × 2 m plots using a completely randomized design. Cattle preference was evaluated in spring (December 2016 and 2017), summer (March 2017), and autumn (May 2017) using six Braford steers that grazed the plots for 4 h on two consecutive days. Pre-grazing forage yield, plant height, leaf-blade length, leaf-blade width, and the proportions of five leaf tissues at three leaf regions were measured at each date. Cattle preference was variable among the three species and evaluation dates. Paspalum atratum exhibited the highest pre-grazing forage yield, and constituted the tallest plants with the longest leaves during the summer. Urochloa brizantha showed the greatest proportion of vascular bundle sheath (17–30% at the midrib region, 25–31% at the interveinal region and 14–23% at the margin region) and P. atratum exhibited the greatest number of primary vascular bundle. Cattle preference was negatively correlated with the number of primary vascular bundle, pre-grazing forage yield, plant height and leaf-blade length.

Grasses doi: 10.3390/grasses4040039

Authors: Meshack Rodgers Wafula Francis Namasake Muyekho Everlyne M’mbone Muleke Leonard Samita Wamocho Joseph Wanjala Munyasi Ann Indetie Hoka

Napier grass (Cenchrus purpureus Schumach) is an important forage crop and livestock feed. However, its yield and quality in Kenya are often limited by Napier grass headsmut and stunt disease. Napier grass genetic improvements through mutation breeding and selection could avail cultivars with increased forage. This study investigated the response of embryogenic calli to different levels of colchicine in inducing polyploidy in the two germplasms of Napier grass; South africa and Bana grass. The experiments were carried out as a factorial experiment in a completely randomized design (CRD). The colchicine concentrations used were 0, 0.05, 0.1, and 0.2%, and the exposure durations were 24, 48, and 72 h. During the shoot regeneration stage, culturing explants on an MS medium (Murashige and Skoog) supplemented with 0.2 mg L−1 Benzyl Adenine (BAP), 0.1 mg L−1 dichlorophenoxyacetic acid (2, 4-D), and 0.1 mg L−1 indole-3-butyric acid (IBA) was more suitable for shoot regeneration. Chromosome doubling was confirmed by genomic DNA and the stomata size and number. Culturing explants on an MS medium supplemented with 1 mg L−1 IBA, 1 mg L−1 2, 4-D, and 0.5 mg L−1 BAP was more suitable in inducing embryogenic calli in both genotypes. Polyploidy results revealed that a 0.1% concentration of colchicine with two days of treatment established the maximum number of octoploid plantlets induced in vitro, while a 0.2% concentration was very toxic. The stomata size and number of derived octoploid plantlets were bigger with a lower density, a shorter plant height, and a smaller stem diameter, and despite being the first to produce tillers, they were significantly higher than their progenitors. Induced mutants also had a significantly higher number of chromosomes and showed different band patterns and distances during gel electrophoresis. However, we recommend the use of flow cytometry to confirm the ploidy level. The superior mutant plantlets can be selected and recommended for characterization across representative agro-ecologies for large-scale production and used in Cenchrus purpureus breeding programs in Kenya and its environments.

Grasses doi: 10.3390/grasses4030038

Authors: Isadora Osório Maciel Aguiar Freitas Antonio Leandro Chaves Gurgel Marcos Jácome de Araújo Tairon Pannunzio Dias-Silva Edy Vitória Fonseca Martins Rafael de Souza Miranda Luís Carlos Vinhas Ítavo Gelson dos Santos Difante João Virgínio Emerenciano Neto

Agro-industrial residues can improve the fermentation quality of tropical forage grass silages when used as additives, but a systematic synthesis of their effectiveness is limited. This integrative review aimed to identify the main residues used as additives in silages and assess their effects on the fermentation process. Following the PVO (population, variable of interest, and outcome) protocol, searches were conducted in the Wiley Online Library, Web of Science, and SCOPUS databases, with no restrictions on language, time, or region. The guiding question was: “What are the main agro-industrial residues used as additives in the ensiling of tropical forage grasses?” Of the 1414 documents initially retrieved, 138 were selected after screening titles, abstracts, and keywords. After removing duplicates and full-text evaluation, 58 studies met the inclusion criteria. Brazil led in the number of studies (89.66%). Elephant grass (Pennisetum purpureum Schum.) was the most studied forage (34.21%). Citrus pulp (13.79%) and coffee husk (12.07%) were the most evaluated residues. The addition of residues promoted a reduction in pH (66.07%), ammonia nitrogen (71.74%), buffer capacity (57.14%), and the concentrations of acetic (52.17%), propionic (52.63%), and butyric (55.00%) acids. Lactic acid content increased in 32.76% of studies; gas and effluent losses decreased in 69.57% and 86.36% of cases, respectively. Citrus pulp and coffee husk are the most used residues, enhancing fermentation quality. It is concluded that the use of agro-industrial residues in the ensiling of tropical forage grasses has the potential to improve fermentation quality.

Grasses doi: 10.3390/grasses4030037

Authors: Cristiana Maduro Dias Vanessa Melo Helder Nunes Alfredo Borba

This study evaluated the effect of Acacia melanoxylon inclusion in Medicago sativa silage on chemical composition, fermentation quality, in vitro digestibility, gas production, and energy value. Due to its high moisture content, M. sativa presents challenges for ensiling. A. melanoxylon, a woody legume with high dry matter (DM) content, was tested as a structural additive. Five treatments were prepared—control (100% M. sativa) and mixtures with 6, 12, 24, and 48% A. melanoxylon (fresh basis)—and ensiled for 45 days under vacuum. Silages were analyzed for DM, crude protein, fiber fractions, pH, ammonia nitrogen, in vitro digestibility, gas production kinetics, and estimated energy values (ME and NEL). Increasing Acacia raised DM (17.75 ± 0.04 → 28.45 ± 0.11%) and reduced pH (5.86 ± 0.01 → 4.53 ± 0.01) and NH3-N/Total N (11.38 ± 0.10% → 8.05 ± 0.10%), indicating improved fermentation quality. Conversely, crude protein, digestibility (IVDMD 62.61 ± 0.05% → 48.02 ± 0.16%), and cumulative gas at 96 h decreased, as did energy values (ME 5.91 → 4.45 MJ/kg DM; NEL 3.13 → 2.02 MJ/kg DM) at higher inclusion levels; gas-kinetic parameters reflected the same trend (lower b and c). Overall, A. melanoxylon acts as a structural co-ensiling option that increases DM and supports fermentation quality while clearly delineating nutritional and fermentability trade-offs; low-to-moderate inclusion (6–12%) appears advisable to balance process benefits against acceptable nutritional penalties.

Grasses doi: 10.3390/grasses4030036

Authors: Diego F. Aviles Alondra Cruz Caitlyn E. Cooper Whitney L. Crossland S. V. Krishna Jagadish Aaron B. Norris

As traditional forage crops demand substantial water, exploring alternatives with lower water demands can mitigate the strain on water supplies. This pot study evaluated five annual warm-season forages (forage sorghum (FS) [Sorghum bicolor (L.) Moench], prussic acid-free forage sorghum (PF) [Sorghum bicolor subsp. Drummondii], sorghum x sudangrass hybrid (SS) [Sorghum bicolor x drummondii], sudangrass (SU) [Sorghum sudanense (Piper) Stapf], and pearl millet (PM) [Pennisetum glaucum (L.) R. Br.]) under two different irrigation treatments (40% and 80% ETo). Morphological (leaf area, leaf count, plant height), biomass yield, nutritional content (nitrogen (N), acid detergent fiber, and in vitro true digestibility (IVTD)), and water use efficiency (WUE) parameters were assessed at 35 and 49 days after planting (DAP). Irrigation effects varied with time, more strongly influencing nutritive value at 35 DAP and morphological traits at 49 DAP. WUE was significantly affected by irrigation at both timepoints. No single forage consistently outperformed across all metrics. PF and SU had the most biomass (p < 0.01), while PM had the greatest N content (p < 0.01). However, PF and SU had the highest WUE for biomass and digestible dry matter (p < 0.01). These findings suggest PF and SU may improve forage system sustainability under limited water availability.

Grasses doi: 10.3390/grasses4030035

Authors: Ana E. de Villalobos Alejandro Ribet Sofía Vivas Leonela Schwerdt

This study examines the growth dynamics of Nassella tenuis (Phil.) Barkworth, a palatable perennial tussock grass, abundant in the natural grasslands of Central Argentina. It focuses on the effects of water regimes and grazing history. Plants were collected from sub-humid and semiarid grasslands with contrasting grazing histories (grazed and ungrazed) and cultivated under controlled conditions. Key growth traits, such as leaf elongation, senescence, and net growth rates, as well as tiller production, were assessed across the growth cycle. The results reveal that sub-humid grasslands favor faster growth rates and higher tiller production, while semiarid grasslands exhibit lower growth rates, potentially reflecting adaptive strategies for water-limited environments. Seasonal analysis revealed distinct life cycle patterns: plants from sub-humid grasslands exhibited higher elongation rates during autumn and spring, whereas growth in semiarid plants remained consistently low across seasons. Grazing history significantly influenced growth patterns, with grazed plants showing reduced tiller numbers and growth rates but lower senescence rates, particularly in semiarid grasslands. These findings underscore the importance of aligning grazing management practices with the growth dynamics of N. tenuis and the water regime of the site to optimize forage production while maintaining grassland resilience.

Grasses doi: 10.3390/grasses4030034

Authors: Amarildo Pedro da Silva Alexandre Menezes Dias Anderson Ramires Candido Eva Nara Oliveira Gomes Juliana Oliveira Batistoti Luís Carlos Vinhas Ítavo Geraldo Tadeu dos Santos Gelson dos Santos Difante Elson Martins Coelho

Pearl millet (Pennisetum glaucum L.) is a promising crop for silage production in the Cerrado biome, but its use is still limited, and the ideal age for ensiling has not been well defined. This study aimed to evaluate the ADRf 6010 pearl millet hybrid at four harvest ages for ensiling: 75, 85, 95, and 105 days after planting (DAP). Forage production (green and dry forage mass), chemical composition, and fermentation parameters were analyzed. Harvested forage was chopped into 2.0 cm particles and treated with a concentration of 1 × 105 CFU/g (Colony Forming Units; Lactobacillus plantarum CNCM I-3736 and Pediococcus acidilactici CNCM I-4622) of fresh forage. Forage mass increased linearly with harvest age. At 105 days of growth, the crop yielded 65,980 kg/ha of fresh forage and 15,569 kg/ha of dry matter. The dry matter (DM) and neutral detergent fiber (NDF) concentrations also increased with advancing harvest age. The concentrations of crude protein (CP), non-fibrous carbohydrates (NFC), and in vitro dry matter digestibility (IVDMD) decreased with increasing harvest age before ensiling. In the silages, pH, ammoniacal nitrogen (NH3-N), effluent loss, gas losses, and silage density decreased linearly, while DM recovery increased. With advancing harvest age, there was a positive linear increase in the concentrations of DM, NDF, and acid detergent fiber (ADF). On the other hand, CP, NFC, and IVDMD showed a negative linear trend. Based on the results, the ADRf 6010 pearl millet hybrid demonstrated high forage yield and favorable fermentative characteristics when harvested at different growth stages during the summer season. Advancing harvest age resulted in increased forage mass, dry matter content, and dry matter recovery, along with reduced fermentation losses such as effluents and gases. Although later harvests led to reductions in crude protein concentration and in vitro digestibility, these effects were compensated for by the higher dry matter yield per hectare and better preservation conditions. Thus, ADRf 6010 pearl millet is a promising crop for silage production under tropical conditions.

Grasses doi: 10.3390/grasses4030033

Authors: Daniele Monteiro Ribeiro Sabrina de Nazaré Barbosa dos Santos Dayana Castilho dos Santos Ferreira Júlia Fernanda Ferreira de Miranda Job Teixeira de Oliveira Fernando França da Cunha Caio Lucas Alhadas de Paula Velloso Priscilla Andrade Silva Cândido Ferreira de Oliveira Neto

Forage sorghum (Sorghum bicolor (L.)) is a cereal native to Africa and belongs to the family Poaceae. It is a forage with a C4 photosynthetic pathway that stands out for its ability to adapt to different environments; it is able to produce even in unfavorable circumstances. The objective of this study was to analyze the attenuating effect of the brassinosteroid hormone in the form of 24-epibrassinolide on forage sorghum plants subjected to water deficit and rehydration. A completely randomized design (CRD) was used in the experiment. A 2 × 3 × 5 factorial arrangement was used, with two water conditions (water deficit and rehydration), three brassinosteroid doses (0 nM, 50 nM, and 100 nM as 24-epibrassinolide), and five replicates. The experiment was conducted in a greenhouse. Sorghum seeds were sown in pots with a capacity of 3 kg of substrate. Analyses were performed on the roots and leaves of sorghum plants at different growth stages. The macronutrients (N, P, K, Ca, and Mg) were analyzed in the soil physics laboratory. As a result, the content of N, P, K, Ca, and Mg decreased under a water deficit and was then restored by the hormone 24-epibrassinolide, which was able to restore these nutrients. The effect of the hormone under rehydration had a positive effect, increasing the levels of nutrients. Given the above, it was possible to conclude that there were no significant divergences between the treatments during the period of irrigation suspension. Among the tested concentrations, 50 nM of 24-epibrassinolide showed the most consistent improvements in nutrient concentrations under water-deficit conditions, suggesting a potential role in mitigating nutritional imbalance during stress. Rehydrated plants maintained nutrient levels similar to the controls regardless of 24-epibrassinolide application. However, it is important to note that nutritional quality indices such as crude protein and total digestible nutrients (TDN) were not evaluated in this study, which limits direct conclusions about the forage nutritional value.

Grasses doi: 10.3390/grasses4030032

Authors: Amilton Gabriel Siqueira de Miranda Policarpo Aguiar da Silva Job Teixeira de Oliveira Fernando França da Cunha

Biodegradable hydroretentive polymers, such as UPDT®, have emerged as promising alternatives to synthetic hydrogels, particularly in pasture systems where sustainable water management is crucial. These materials enhance subsurface drip irrigation by maintaining soil moisture, which supports germination and early root development until roots access deeper water reserves. However, their degradation dynamics in tropical forage systems remain poorly characterized, posing a challenge to long-term application strategies. This study aimed to evaluate the effects of different UPDT® doses (0, 7.5, 15, 22.5, and 30 kg ha−1) on the morphological and agronomic traits of Mombaça grass under controlled conditions. After a uniformity cycle, treatments were evaluated across four cultivation cycles with monitored irrigation to avoid water deficits. Morphogenetic traits such as number of live leaves (NLL), final number of emerging leaves (NEmL), leaf appearance rate (LAR), and stem elongation rate (SER), as well as shoot dry mass (SDM), were analyzed. Results showed that morphological variables responded quadratically to polymer doses during the initial and intermediate cycles. In the final cycle, reductions in these traits and in water productivity suggested the onset of polymer degradation and loss of hydroretentive capacity. Agronomic traits were influenced throughout all cycles, with the fourth cycle showing the highest SDM due to elevated temperatures. These findings highlight the need to better understand the degradation kinetics of biodegradable hydrogels such as UPDT® in tropical pastures. Field trials are recommended to define optimal reapplication intervals and integrate degradation monitoring into irrigation planning, ensuring long-term sustainability in pasture management.

Grasses doi: 10.3390/grasses4030031

Authors: Carlos Eduardo Avelino Cabral Luis Carlos Oliveira Borges Anna Cláudia Cardoso Paimel Eildson Souza de Oliveira Silva Izabela Aline Gomes da Silva Camila Fernandes Domingues Duarte Lucas Gimenes Mota Anne Caroline Dallabrida Avelino Carla Heloisa Avelino Cabral

Sulfur-containing fertilizers increase production costs, which leads to low utilization of this nutrient. Thus, evaluating how the absence of sulfur influences the early development of Urochloa brizantha is essential. Study was conducted in a greenhouse at the Federal University of Rondonópolis in a completely randomized design, with six treatments in a 3 × 2 factorial scheme, and eight replications. Three cultivars of U. brizantha (Marandu, Xaraés and Piatã) were evaluated under two fertilization strategies: with or without sulfur fertilization. Sufur presence increased the number of leaves and forage mass, in which cultivar Xaraés presented the greatest means. Piatã was the cultivar most sensitive to sulfur deficiency at establishment, which reduced forage mass, number of leaves and number of tillers by 42%, 32%, and 45%, respectively. Despite these differences between cultivars, sulfur efficiently increased the forage yield. Sulfur fertilization increased the concentrations of nutrients in the plants without significantly affecting the uptake of nitrogen, phosphorus, potassium, calcium and magnesium. Sulfur omission resulted in increased phosphorus uptake in all grass. In contrast, Marandu grass exhibited the greatest reduction in sulfur uptake. Therefore, the use of sulfur in the fertilization of grasses is recommended, it is important to evaluate the responses of each cultivar to better adjust the fertilization management.

Grasses doi: 10.3390/grasses4030030

Authors: Manabu Tobisa Yoshinori Uchida Yoshinori Ikeda

Arbuscular mycorrhizal (AM) fungi (AMF) form a symbiotic association with terrestrial plants and increase growth and productivity. The relationships between the growth of centipedegrass (CG) and AMF are not well understood. We monitored the growth and AM colonization of CG growing on the four slopes (north, east, south, and west) of a pasture, to obtain information on aspect differences in the soil chemical properties–grass–AMF association. Soil properties almost always varied between the slope aspects. The total soil N, C, EC, and moisture tended to be highest on the northern aspect, whereas the soil available P and pH tended to be highest on the western and southern aspects, respectively. Despite the aspect differences in the microclimate and soil properties, CG grew well in all aspects, showing similar dry matter weights (DMW) for the fouraspects. Furthermore, the AM colonization of CG, in any characteristic structures (internal hyphae, vesicles, and arbuscules), was not significantly different between the slope aspects on most measurement occasions, although the colonization usually varied between the seasons and years. There were no relationships between the DMW and AM characteristic structure colonization and between the DMW and soil chemical properties. However, the colonization of the arbuscules and vesicles of the CG had a correlation with some soil chemical properties. The results suggest that AM colonization on CG growing in a hill pasture did not differ between the slope aspects. This may be a factor contributing to the high adaptability of the grass to all slope aspects.

Grasses doi: 10.3390/grasses4030029

Authors: Amber A. Taylor John H. Fike Vitor R. G. Mercadante Gabriel J. Pent

Records from 2012 to 2019 for two herds were analyzed to determine how tall fescue (Schedonorus arundinaceus (Schreb.) Dumont) endophyte (Epichloë coenophialum) status affected the productivity of spring-calving cows and calves. Pastures either contained tall fescue with wildtype endophyte (high levels of ergot alkaloids) or novel- or endophyte-free tall fescue (largely ergot alkaloid free). The experimental design was a randomized complete block with year as the replication unit. Forage samples from the farm with toxic endophyte-infected tall fescue contained 1136 ± 413 ppb total ergot alkaloids, while forage from the non-toxic pastures on the second farm contained 118 ± 83 ppb total ergot alkaloids. Artificial insemination pregnancy rates and calving rates were greater (p < 0.05) for cows that grazed non-toxic tall fescue (51.2 ± 2.8% and 93.5 ± 1.4%, respectively) than for cows on toxic endophyte-infected tall fescue (43.3 ± 2.8% and 88.8 ± 1.4%, respectively). Birth weights and weaning weights were greater (p < 0.05) for calves from the non-toxic tall fescue system (37 ± 1 kg and 278 ± 8 kg, respectively) than for calves from the toxic endophyte-infected tall fescue system (33 ± 1 kg and 254 ± 8 kg, respectively). Raising cattle on tall fescue without the toxic endophyte improved cow and calf productivity.

Grasses doi: 10.3390/grasses4030028

Authors: Nágila Sabrina Guedes da Silva Alexandre Campelo de Oliveira Baltazar Cirino Júnior Rhaiana Oliveira de Aviz Kedes Paulo Pereira Domingos Sávio Marques de Menezes Vieira Claudenilde de Jesus Pinheiro Costa Jucelane Salvino de Lima Jamiles Carvalho Gonçalves de Souza Henrique Evaristo Jorge Oliveira de Souza

Molybdenum fertilization represents a viable alternative for improving forage quality, potentially complementing or enhancing the effects of nitrogen fertilization. This study aimed to determine whether foliar or soil application of molybdenum would increase the crude protein content and digestibility of sorghum cultivated as a monoculture or intercropped with cowpea. The first experiment followed a 2 × 2 + 2 factorial design, including two application methods (foliar or soil), two cropping systems (monoculture or intercropping), and two additional control treatments (with and without molybdenum). In the second experiment, a split-plot design was used to assess the effects of molybdenum fertilization on the in situ digestibility of sorghum from monoculture and intercropping systems. Molybdenum fertilization increased the levels of crude protein, total carbohydrates, and soluble fractions. It also enhanced the disappearance rate, potential degradability, and effective degradability of sorghum, regardless of the application method or cropping system. Foliar or soil application of molybdenum is recommended to optimize the crude protein content and in situ digestibility of sorghum cultivated either as a monoculture or intercropped with cowpea.

Grasses doi: 10.3390/grasses4030027

Authors: Yuxi Wang Alan Iwaasa Tim McAllister Surya Acharya

Three purple prairie clover (PPC; Dalea purpurea Vent.) varieties, namely Common seed (CS), AC Lamour (ACL) and Bismarck (BIS), were established in plots of irrigated land (rain-fed plus irrigation, Lethbridge, AB) and dryland (rain-fed only, Swift Current, SK) to assess its agronomic characteristics and nutritive value under different ecoclimate and growing conditions in Western Canada. Each seed source was replicated in four test plots arranged as a randomized complete block design at each experimental site. Forage mass on dry matter (DM) basis, canopy height, proportions of leaf and stem and nutritive value were determined at vegetative (VEG), full flower (FF) and late flower (LF) phenological stages. The forage masses of the three PPC varieties were similar (p < 0.05) at each phenological stage with the mean values for VFG, FF and LF being 4739, 4988 and 6753 kg DM/ha under the Lethbridge irrigated conditions, and 1423, 2014 and 2297 kg DM/ha under the Swift Current dryland conditions. The forage mass was higher (p < 0.001) under Lethbridge irrigation than under Swift Current dryland conditions and increased (p < 0.05) with maturity. The three varieties had similar concentrations of organic matter (OM), neutral detergent fibre (NDF), acid detergent fibre (ADF) and crude protein (CP) and in vitro DM digestibility (DMD) at each phenological stage, but CP concentration and in vitro DMD decreased (p < 0.001) whilst NDF and ADF concentration increased (p < 0.001) with maturity. Purple prairie clover grown at Lethbridge irrigated land had higher (p < 0.001) DMD, OM and CP, but lower (p < 0.001) NDF, ADF and condensed tannin concentrations than that grown at Swift Current dryland conditions. These results indicate that PPC has great potential as an alternative legume forage for the cattle industry.

Grasses doi: 10.3390/grasses4020026

Authors: Sirio Douglas da Silva dos Reis Marco Antonio Previdelli Orrico Junior Michely Tomazi Ana Carolina Amorim Orrico Stéfane de Sousa Cunha Isabele Paola de Oliveira Amaral

The objective of this study was to evaluate the impact of different nitrogen sources (urea, compost, and digestate) on N2O and CH4 emissions and the forage production of Piatã grass in tropical pastures, with the aim of identifying the fertilization practices that can balance productivity with environmental mitigation. The experiment included 10 forage cuts over a period of 14 months, from January 2017 to February 2018. The CH4 and N2O emissions were monitored using closed chambers and analyzed by gas chromatography. The forage production was assessed by weighing and drying the material. The emission intensity was calculated based on the global warming potential of the gases. The data were analyzed using ANOVA and compared by Tukey’s test (p ≤ 0.05). Fertilizer application increased the N2O emissions, with the highest flux (79.56 mg N-N2O/m2/day) observed for the digestate treatment (p < 0.01). The N2O consumption was the most significant for the control treatment (−5.90 mg N-N2O/m2/day) in July. The CH4 oxidation was prevalent across all the treatments, with the highest oxidation for the urea treatment (−49.80 µg C-CH4/m2/day) two days after fertilization. The dry matter production (DMP) was the highest with urea during the summer (16.9 t/ha; p < 0.01). The emission intensity values were 243.41 kg CO2eq/t DM for urea, 103.44 kg CO2eq/t DM for digestate, and 27.35 kg CO2eq/t DM for compost (p < 0.01). The compost application stimulated CH4 oxidation. In conclusion, compost can be considered an important alternative for fertilizing pasture areas, both from a productive and environmental perspective.

Grasses doi: 10.3390/grasses4020025

Authors: Reagan W. Hejl Matthew M. Conley Julia G. Farias Desalegn D. Serba Clinton F. Williams

Fertilizer application is a critical component of turfgrass management as it influences growth, color, stress tolerance, and overall quality. However, limited information exists on how fertilizer application, particularly nitrogen (N), affects hybrid bermudagrass performance and actual plant evapotranspiration (ETa) in both well-watered and deficit irrigation scenarios. A 7-week greenhouse experiment was conducted over two replicated runs to evaluate responses of ‘TifTuf’ hybrid bermudagrass (Cynodon dactylon × C. traansvalensis Burtt Davy) to three nitrogen rates (0, 2.4, and 4.8 g N m−2 month−1) and three irrigation levels (1.0, 0.65, and 0.30 × ETa). Fertilized turfgrass exhibited 11–12% greater ETa compared to unfertilized turfgrass, with no significant differences between the two fertilizer rates. Under well-watered conditions (1.0 × ETa), the high nitrogen rate significantly improved visual quality (7.8) relative to the unfertilized control (7.1) and the low-rate treatment (7.4). High-rate fertilizer application significantly enhanced visual quality at both deficit levels (7.2 and 6.6, at 0.65 and 0.30 × ETa, respectively) compared to the unfertilized control (6.2 and 5.9, at 0.65 and 0.30 × ETa, respectively). At 0.30 × ETa, low-rate fertilizer application also significantly improved visual quality (7.0) compared to the unfertilized control. Soil nitrate-N levels increased with higher nitrogen application (1.30 ppm, 0.48 ppm, and 0.37 ppm, respectively, for high-rate, low-rate, and unfertilized), and shoot tissue analysis revealed greater N concentration in fertilized turfgrass (1.51%, 1.24%, and 0.85%, respectively, for high-rate, low-rate, and unfertilized). Clipping production and water use efficiency (WUE) were also improved with fertilization, although root development was hindered at the 0.30 × ETa irrigation level. These findings demonstrate that nitrogen fertilization improves visual quality, shoot growth, WUE, and drought response; however, tradeoffs such as elevated water use and nitrate-N leaching risk necessitate careful management to balance turfgrass performance with water conservation and ecosystem service preservation.

Grasses doi: 10.3390/grasses4020024

Authors: Lucas Aquino Alves Fernando Arnuti Leandro Bittencourt de Oliveira Moacir Tuzzin de Moraes Luiz Gustavo de Oliveira Denardin Ibanor Anghinoni Paulo César de Faccio Carvalho Tales Tiecher

In integrated crop–livestock systems (ICLSs), grazing intensity and crop rotation influence residue dynamics, making it essential to assess shoot and root contributions to soil carbon (C) and nitrogen (N) inputs. This study aimed to assess the shoot and root biomass of Italian ryegrass, soybean, and maize; the distribution of roots within the soil profile; and the contributions of shoot and root biomass to soil C and N under varying winter grazing intensities and summer crop rotations. The experiment was conducted within a long-term (12-year) field protocol, arranged in a randomized complete block design with split plots and four replicates. Grazing intensity was defined as the following: (i) moderate grazing—forage allowance equivalent to 2.5 times the potential dry matter intake of sheep, and (ii) low grazing—forage allowance equivalent to 5.0 times the intake potential. Grazing intensities (moderate and low) were allocated to the main plots, while cropping systems—monoculture (soybean/soybean) and crop rotation (soybean/maize)—were assigned to the subplots. Soil depth layers (0–10, 10–20, 20–30, and 30–40 cm) were treated as sub-subplots. Root samples of Italian ryegrass, soybean, and maize were collected using the soil monolith method. Low grazing intensity (8.6 Mg ha−1) promoted greater aboveground biomass production of Italian ryegrass compared to moderate intensity (6.6 Mg ha−1). Maize exhibited a higher capacity for both root and shoot biomass accumulation, with average increases of 85% and 120%, respectively, compared to soybean. Root biomass was primarily concentrated in the surface soil layer, with over 70% located within the top 10 cm. Italian ryegrass showed a more uniform root distribution throughout the soil profile compared to soybean and maize. Carbon inputs were higher under crop rotation (17.2 Mg ha−1) than under monoculture (15.0 Mg ha−1), whereas nitrogen inputs were greater in soybean monoculture (0.23 Mg ha−1) than in crop rotation (0.16 Mg ha−1). Low grazing intensity in winter and summer crop rotation with high-residue and quality species enhance the balance between productivity and soil C and N inputs, promoting the sustainability of ICLSs.

Grasses doi: 10.3390/grasses4020023

Authors: Mitiku A. Mengistu Desalegn D. Serba Matthew M. Conley Reagan W. Hejl Yanqi Wu Clinton F. Williams

Bermudagrass is a warm-season turfgrass commonly grown in drought-prone areas. Harnessing natural genetic variation available in germplasm is a principal strategy to enhance its resilience to drought stress. This study was carried out to assess the comparative performance of bermudagrass hybrids under drought conditions and their subsequent recovery following the drought period. A total of 48 hybrids, including 2 commercial cultivars, ‘Tifway’ and ‘TifTuf’, were established under optimum growth conditions in the greenhouse and then subjected to drought stress by withholding irrigation for four weeks. The dry-down experiment was laid out in a randomized complete block design with four replications. Turf color, visual quality, and active spectral reflectance data were collected weekly and used to assess the health and vigor of the hybrids during progression of the drought stress for four weeks and through recovery after rewatering. Analysis of variance revealed significant differences among the hybrids for color, visual quality, and spectral vegetation indices. A multivariate analysis grouped the hybrids into drought-tolerant with full recovery after rewatering, moderately tolerant, and susceptible to extended drought stress without recovery. These results showed the prevalence of genetic variation for drought tolerance and proved instrumental in the development of bermudagrass cultivars resilient to drought stress and improved water use efficiency.

Grasses doi: 10.3390/grasses4020022

Authors: Alex Marciano dos Santos Silva Emanoella Karol Saraiva Otaviano Caio Macret Gomes Alexandre Fameli Mammana Larissa Fernanda Garcia Carvalho Sila Carneiro da Silva

Botanical richness and diversity play crucial roles in regulating ecosystem functions and contribute to the sustainable intensification of perennial grasslands. This approach can be achieved through simultaneous or partial production of grasses in the same field, leading to enhanced productivity, reduced dependence on inorganic fertilizers and pesticides, and mitigating effects of edaphoclimatic variations. However, the existing literature predominantly focuses on associations between forage grasses and legumes or annual species. Furthermore, the subject should be explored under tropical conditions and environments, particularly considering the associations among well-managed perennial forage grasses. The interaction among perennial tropical forage grasses presents an alternative for exploration in the tropics, given the vast diversity of species and genotypes available. This review discusses the existing literature on multispecific pastures, elucidating the potential benefits for pastoral ecosystems. The association of perennial tropical forage grasses represents an emerging research area offering strategic opportunities for the sustainable intensification of animal production systems. Mixed pastures may be an economical and ecological alternative and enhance the production and sustainability of forage systems in the tropics. However, challenges persist in selecting plant species to achieve multifunctionality and understanding the underlying mechanisms shaping botanical diversity and productive performance within an association. This review emphasizes that understanding the morphological and agronomic characteristics of species and genotypes intended for cultivation in association is key to grasping the dynamics of competition for aboveground and belowground resources and creating combinations that deliver specific ecosystem services.

Grasses doi: 10.3390/grasses4020021

Authors: John Jairo Junca Paredes Sandra Guisela Durango Morales Stefan Burkart

The cattle sector plays a critical role in Peru’s agricultural economy, yet it faces challenges related to low productivity and environmental degradation. Sustainable alternatives like silvo-pastoral systems (SPSs) offer promising solutions to enhance both economic returns and ecological outcomes in cattle farming. This study examines the economic viability of an intensive SPS (SPSi) compared to traditional monoculture grass systems in San Martín, Peru. The SPSi under study is in the evaluation phase, integrates grasses, legumes, shrubs, and trees, and has the potential to enhance cattle farming profitability while simultaneously offering environmental benefits such as improved soil health and reduced greenhouse gas emissions. Through a discounted cash flow model over an eight-year period, key profitability indicators—Net Present Value (NPV), Internal Rate of Return (IRR), Benefit–Cost Ratio (BC), and payback period—were estimated for four dual-purpose cattle production scenarios: a traditional system and three SPSi scenarios (pessimistic, moderate, and optimistic). Monte Carlo simulations were conducted to assess risk, ensuring robust results. The results show that the NPV for the traditional system was a modest USD 61, while SPSi scenarios ranged from USD 9564 to USD 20,465. The IRR improved from 8.17% in the traditional system to between 26.63% and 30.33% in SPSi scenarios, with a shorter payback period of 4.5 to 5.8 years, compared to 7.98 years in the traditional system. Additionally, the SPSi demonstrated a 30% increase in milk production and a 50% to 250% rise in stocking rates per hectare. The study recommends, subject to pending validations through field trials, promoting SPSi adoption through improved access to credit, technical assistance, and policy frameworks that compensate farmers for ecosystem services. Policymakers should also implement monitoring mechanisms to mitigate unintended consequences, such as deforestation, ensuring that SPSi expansion aligns with sustainable land management practices. Overall, the SPSi presents a viable solution for achieving economic resilience and environmental sustainability in Peru’s cattle sector.

Grasses doi: 10.3390/grasses4020020

Authors: Néstor Eduardo Villamizar Frontado Gelson dos Santos Difante Alexandre Romeiro de Araújo Denise Baptaglin Montagner Jéssica Gomes Rodrigues Gabriela Oliveira de Aquino Monteiro Manuel Cláudio Motta Macedo Marislayne de Gusmão Pereira Amanda Eunice Silva Moura Eduardo Weisz Arze

This study evaluated the phosphorus use efficiency (PUE) in two genotypes and one cultivar of Brachiaria decumbens (HD1, HD4, and Basilisk) and the productive, morphogenic, and structural responses. The experimental design used was randomized blocks with five P rates (0, 13, 26, 52, and 104 mg dm−3). There was no forage × P rate interaction (p > 0.05), but the P rates affected the leaf appearance rate (TAR; p = 0.0314), leaf life span (LLS; p = 0.0207), phyllochron (PC; p = 0.0207), leaf elongation rate (LER; p = 0.0350), stem elongation rate (SER; p = 0.0109), and the number of live leaves (NLL; p = 0.0033). The LAR, LLS, and PC followed quadratic trends, increasing up to 52 mg dm−3, while the PC declined. The FLL, SER, and NLL increased linearly. HD1 had the highest final leaf length, LER, and NLL, while Basilisk had the lowest. There was an interaction for tiller population density (p = 0.0431), with increases of 0.26, 0.28, and 0.24 tillers for HD4, HD1, and Basilisk, respectively. Forage production (FP) increased with P, gaining 0.51 g of DM for each mg dm−3 of P added. The HD1 genotype showed higher FLL, LER, NLL, FP, and higher PUE than the HD4 genotype and the Basilisk cultivar. HD1 was more responsive to higher P rates for root production, indicating a greater need for nutrients to reach its productive potential. Phosphate fertilization positively influenced morphogenesis and forage production in the evaluated genotypes and cultivars. The HD1 genotype stood out in relation to the others, showed superiority in forage and root production, and demonstrated greater efficiency in the use of P, at a dose of 13 mg dm−3.

Grasses doi: 10.3390/grasses4020019

Authors: María Elena Vago Paula Virginia Fernández Juan Pedro Ezquiaga Santiago Javier Maiale Andrés Alberto Rodriguez Juan Manuel Acosta Maximiliano Gortari Oscar Adolfo Ruiz Marina Ciancia

Previous studies in the Salado River Basin (Argentina) demonstrated that the introduced forage species, Lotus tenuis Waldst. & Kit. ex Wild. (Fabaceae), possesses high tolerance to abiotic stresses—including flooding, alkalinity, salinity, and drought. The efficient biological fixation of nitrogen in a region with a scarce presence of native legumes is one of its advantages. Despite these qualities, a year-long characterization of cell wall (CW) polysaccharides in Lotus tenuis and their relationship with the high nutritional quality is missing. In this study, seasonal parametric investigations of L. tenuis, regarding its photosynthetic and ionic status, modifications in CW composition, and concomitant nutritional quality, were performed. Our results demonstrate the high plant digestibility and protein content of this legume, even in summer, when most accompanying species reduce their forage quality. Regarding gas production kinetics (in vitro production is a proxy for the animal rumen’s output), spring biomass had the highest values. The CW material yields are similar throughout the year, but with differences in polysaccharide composition. In summer and winter, pectins predominate, while in the regrowth periods (spring and autumn), pectins and β-glucans are found in similar amounts. This work confirms that Lotus tenuis can help optimize grassland productivity in challenging mesophytic terrains to increase livestock productivity through environmentally friendly services.

Grasses doi: 10.3390/grasses4020018

Authors: María Díaz Julio Alegre Carlos Gómez Carlos García Cesar Arévalo-Hernández

Silvopastoral systems, integrating trees, forages, and livestock, are recognized as a sustainable approach to livestock production. This study evaluated the effect of shade vs. open-field conditions on the yield and nutritive value of Brachiaria decumbens in three systems—Inga edulis (guaba), Eucalyptus torrelliana (eucalyptus), and Cedrelinga cateniformis (tornillo)—in the Peruvian Amazon. A 3 × 2 factorial design with three replicates was used to analyze forage production (mass and mass by harvest), quality (NDF, protein, digestibility, metabolizable energy), and soil variables (bulk density, pH, organic matter, moisture, porosity, etc.). Most interactions were non-significant, except forage mass by harvest (FMH, p = 0.0328). B. decumbens in the guaba system under shade had the highest FMH (1406 kg DM ha−1), while the tornillo system showed elevated protein (10.63%). Protein was significantly higher under shade (9.55%) than in open field. Eucalyptus increased neutral detergent fiber (69.72%), whereas guaba provided the greatest metabolizable energy (8.08 MJ kg−1 DM). Soil analyses revealed improved moisture and CEC under guaba, while tornillo boosted soil phosphorus. Principal component analysis confirmed these associations (82.3% variance). B. decumbens grown under the shade of guaba or tornillo appears to enhance forage productivity and soil fertility, representing a promising strategy for sustainable tropical livestock management.

Grasses doi: 10.3390/grasses4020017

Authors: Lwando Mbambalala Thamsanqa Doctor Empire Mpanza Tlou Julius Tjelele Lusanda Ncisana Sphesihle Mkhungo Lucky Sithole Mpho Siennah Nzeru Patrick Ngwako Rakau Zikhona Theodora Rani-Kamwendo Ntuthuko Raphael Mkhize

Erratic rainfall and extended dry periods challenge forage production and livestock feed sustainability in dryland agriculture regions. This study investigated the effects of planting dates and genotype selection on the nutritive value and in-vitro dry matter degradability (IVDMD) of fodder radish genotypes in Midlands of KwaZulu-Natal, South Africa. The experiment followed a completely randomised design with three fodder radish genotypes (Endurance, Line 2, and Nooitgedacht) and five planting dates (December, January, February, March and May). After three months of growth in each planting date, crops were harvested, prepared and analysed for various nutritional parameters including crude protein, fibre content, and IVDMD. Results revealed that December had the highest crude protein (28–31%) across genotypes, while March plantings optimised total non-structural carbohydrates (13.31%) and metabolisable energy (6.64 MJ/kg). The Nooitgedacht genotype demonstrated improved performance, achieving higher IVDMD of 85.54% for leaves in December plantings and 77.51% for tubers in February plantings. Significant interactions between planting dates and genotypes were observed for ash, crude protein, and cellulose in leaves. In conclusion, these findings highlight the crucial role of planting date selection and genotype choice in optimising fodder radish production under dryland conditions, offering valuable insights for enhancing livestock productivity and supporting sustainable rural livelihoods.

Grasses doi: 10.3390/grasses4020016

Authors: James P. Muir José C. Batista Dubeux Junior Mércia V. Ferreira dos Santos Jamie L. Foster Rinaldo L. Caraciolo Ferreira Mário de Andrade Lira Barbara Bellows Edward Osei Bir B. Singh Jeff A. Brady

Forage legumes, besides their use as ruminant feed supplements, contribute to other agricultural, forestry and natural ecosystems’ sustainability around the world. Our objective in this summary is to emphasize that versatility in the face of biotic, abiotic and socio-economic variability is among the most important traits that forage legumes contribute to sustaining human populations in those diverse ecosystems. Forage legumes could contribute even more to agroecosystems if we 1. consider ecosystem services as well as food, feed and fuel production; 2. more fully exploit what we already know about forage legumes’ multiple uses; and 3. focus greater attention and energy exploring and expanding versatility in currently used and novel versatile species. To draw attention to the importance of this versatility to sustainable grasslands, here we review multiple legumes’ roles as forage, bioenergy, pulses (legume seeds for human consumption), pharmaceuticals and cover crops as well as environmental services, in particular soil health, C sequestration and non-industrial organic N. The major points we single out as distinguishing sustainable versatile forage legumes include (1) multiple uses; (2) adaptation to a wide range of edaphoclimatic conditions; (3) flexible economic contributions; and (4) how genomics can harness greater legume versatility. We predict that, because of this versatility, forage legumes will become ever more important as climates change and human pressures on sustainable agro-environments intensify.

Grasses doi: 10.3390/grasses4020015

Authors: Ana Caroline Cerqueira de Melo Vasco Erick R. da Silva Santos Jose C. Batista Dubeux Junior Lynn E. Sollenberger Marcelo O. Wallau Helio Lauro Soares Vasco Neto Jill M. Lance Lori K. Warren Carissa L. Wickens

The pasture–animal interface of warm-season perennial grass–legume mixed pastures has never been investigated in forage-based equine systems. Therefore, this 2-year study investigated the herbage and animal responses under 84-day continuous stocking in mixed pastures of rhizoma peanut (RP, Arachis glabrata Benth) and bahiagrass (BG, Paspalum notatum Flüggé) with 30 kg nitrogen (N) ha−1 (BG-RP) compared to BG pastures fertilized with 120 kg N ha−1 (BG-N120) and no N (BG-N0). Measurements were taken every 14 days, except for intake and in vivo digestibility, which were measured every 28 days. BG-N120 had the highest stocking rate (p = 0.01; 3.7 AU ha−1) in 2019, while BG-N0 had the lowest (p = 0.01; 2.6 AU ha−1) in 2020. Crude protein and digestible energy were greatest (p < 0.05) for BG-N120 and BG-RP in some of the evaluation days in 2019 but similar across pastures in 2020. Crude protein digestibility was greatest (p < 0.05) for BG-RP in the late season. Intake was less (p = 0.03) for horses grazing BG-RP (3.2%BW) compared to BG-N0 (5.0%BW). Nonetheless, no differences (p > 0.05) were observed among pastures for body measurements. The results indicate that BG-RP pastures can improve forage nutritive value and maintain horse body condition while maintaining similar stocking rate to monoculture bahiagrass with high N fertilizer rates.

Grasses doi: 10.3390/grasses4020014

Authors: Wilmer Cuervo Mariana Larrauri Camila Gomez-Lopez Nicolas DiLorenzo

Global beef demand will rise by 40 million tons in 30 years, increasing methane (CH4) emissions. Pigweed (Amaranthus spinosus), an invasive weed abundant in southeastern U.S. pastures, may mitigate CH4. Yet, its potential as a feed additive remains unexplored. The aim of this study was to evaluate the influence of pigweed and its extracts on ruminal fermentation and CH4 production. For Exp 1, ruminal fluid from three American Aberdeen steers was incubated with 0, 2.5%, 5%, or 10% of diet dry matter (DM) of roots, stems, leaves, seeds, or the whole pigweed plant (WHO). In Exp 2, extracts from the leaves and WHO were incubated under the same conditions. For the first experiment, 2.5% of the roots, 5% of the leaves, and 10% of the WHO decreased acetate and butyrate concentrations (p < 0.01). In contrast, the WHO, leaves, and seeds at 2.5% of DM increased propionate concentration (p = 0.05). Increasing levels of WHO, leaves, and seeds quadratically reduced CH4 (p < 0.001). The addition of 2.5 and 5% of leaves and WHO reduced in vitro CH4 production per gr of organic matter fermented (p < 0.01). In Exp 2, based on their CH4 mitigation, the leaves and WHO were extracted, and their phenol (3.2 and 1.1 mg/g of DM, respectively) and flavonoid (19.7 and 1.9 mg/g of DM, respectively) contents were determined. Extracts from WHO (2.5%) decreased acetate and CH4 (p < 0.05), while 5% inclusion decreased gas production and increased ruminal pH (p < 0.03). Leaf extracts (2.5%) increased propionate and reduced acetate: propionate (p < 0.05). The leaves and WHO extracts did not affect IVOMD at either inclusion level (p > 0.4). Extracts at 5% from WHO were more effective than that from leaves in reducing CH4 (27% vs. 4%). The evidence suggests that the inclusion of 2.5 to 5% of WHO extracts shifts ruminal fermentation towards propionate-producing impairing methanogenesis, representing a sustainable strategy to mitigate CH4. This hypothesis must be further assessed under in vivo supplementation of the extracts to beef cattle.

Grasses doi: 10.3390/grasses4020013

Authors: Gêisa Araújo de Oliveira Ossival Lolato Ribeiro Gherman Garcia Leal de Araújo Fleming Sena Campos José Nildo Tabosa Amadeu Regitano Neto Thieres George Freire da Silva Daniele Rebouças de Santana Loures Glayciane Costa Gois

The aim was to evaluate the productivity, agronomic characteristics, and chemical and mineral composition of pearl millet genotypes irrigated with brackish water under the application of agricultural gypsum in two cuts. The experiment was a randomized block design in a 4 (gypsum levels—0, 2, 4, and 8 ton ha−1 applied on the surface) × 3 (pearl millet genotypes—ADR 300, BRS 1501, and IPA BULK 1BF) factorial arrangement, with three replications, irrigated with high brackish water and low sodium. Agricultural gypsum had no significant effect on productivity, agronomic characteristics, and chemical and mineral composition (p > 0.05). In the first cut, higher mean values were found for the percentage of panicle, crude protein, ether extract, in vitro dry matter digestibility, calcium, sulfur, and manganese (p < 0.05). For the second cut, higher results were observed for green matter productivity, dry matter productivity, water use efficiency, stem percentage, stem diameter, average leaf size, panicle size, acid detergent fiber, lignin, cellulose, total carbohydrates, potassium, and copper (p < 0.05). IPA Bulk 1 BF showed a larger panicle size in both cuts (p < 0.05). The evaluated pearl millet genotypes showed desirable agronomic characteristics and tolerance to irrigation with brackish water regardless of gypsum application, thus they are indicated for cultivation in the semi-arid regions.

Grasses doi: 10.3390/grasses4010012

Authors: Edward J. Raynor Pedro H. V. Carvalho Juan de J. Vargas Edilane C. Martins Willian A. Souza Anna M. Shadbolt Afrin Jannat Sara E. Place Kimberly R. Stackhouse-Lawson

Automated head chamber systems (AHCS) are increasingly deployed to measure enteric emissions in vivo. However, guidance for AHCS-derived emissions data analyses pertains to confined settings, such as feedlots, with less instruction for grazing systems. Accordingly, our first objective in this experiment was to determine the utility of two data preprocessing approaches for grazing-based analyses. Using Pearson’s correlation, we compared “simple arithmetic” and “time-bin” averaging to arrive at a single estimate of daily gas flux. For our second objective, we evaluated test period length averaging at 1, 3, 7, and 14 d intervals to determine daily pasture-based emissions estimates under two experimental conditions: herd access to a single AHCS unit vs. two AHCS units. Unlike findings from the confinement-based literature, where slight improvements have been observed, time-bin averaging, compared to simple arithmetic averaging, did not improve gas flux estimation from grazing for CH4 (p ≥ 0.46) or CO2 (p ≥ 0.60). Irrespective of experimental condition, i.e., herd access to a single AHCS unit vs. two AHCS units, assessment of variability of diurnal emissions patterns revealed CH4 flux on pasture had at least half as much variability for the same individuals acclimated in confinement. Using a 7-day test period length interval, aggregating gas flux data at 7 d at a time was adequate for capturing diurnal emissions variation in grazing steers, as no improvement was observed in the percentage of individuals with five of six time bins measured for a 14-day test period length interval. This analysis should provide insights into future research to standardize AHCS data preprocessing across experiments and research groups.

Grasses doi: 10.3390/grasses4010011

Authors: Wesley Lopes Cançado Eugénio da Piedade Edmundo Sitoe Job Teixeira de Oliveira Lêda Rita D’Antonino Faroni Ernandes Rodrigues de Alencar Marcus Vinicius de Assis Silva Fernando França da Cunha

Ozonation of irrigation water is a promising technology that improves the efficiency of irrigation systems. However, it is necessary to investigate the potential adverse effects of the continuous application of this technology on pastures, particularly on Mombaça grass (Panicum maximum cv. Mombaça), to ensure that its benefits are not outweighed by negative impacts. This study aimed to evaluate the impact of ozonated irrigation water on the production of Mombaça grass under different fertilization management practices. The experiment was conducted in a controlled environment using 4.5 L pots, following a completely randomized design with five replications. The experimental setup employed a factorial arrangement, involving two irrigation water sources (with and without ozonation) and two fertilization managements (with and without N and K2O), resulting in 20 experimental units. A 60-day uniformity cycle and three 30-day cycles were performed, assessing water consumption as well as the morphogenic and agronomic characteristics of Mombaça grass. Fertilization with N and K2O increased water consumption and improved the agronomic characteristics of Mombaça grass, promoting greater development and growth in line with its morphogenic traits. Regardless of fertilization, ozonation of irrigation water did not cause harm to growth and biomass yield. Therefore, the technique of ozonating irrigation water can be used in the cultivation of Mombaça grass.

Grasses doi: 10.3390/grasses4010010

Authors: Tong Guo

Plant diversity plays an important role in shaping the carbon cycling of grassland ecosystems. However, differences in the diversity effect on aboveground and belowground carbon storage remains unclear at specific spatiotemporal scales. A transplant experiment was carried out along the gradient of altitude (4600–5200 m) in alpine grasslands of the Qinghai–Tibetan Plateau in the year 2017. Vegetation characteristics like species richness, vegetation cover and height were measured in the years 2020 and 2021. The plant diversity was described by species richness. Then, I calculated the vegetation biomass to quantify the aboveground carbon storage. The belowground carbon storage was represented by soil organic carbon. The results showed that the effect of species richness on belowground carbon storage was significantly positive (p < 0.05) at most altitudes for both years. However, the diversity effect on aboveground carbon storage was weak and inconsistent. The relationship between species richness and belowground carbon storage remained relatively stable over a period of two years. In contrast, the relationship altered greatly in terms of aboveground carbon storage in terms of inter-annual changes. Precipitation of growing seasons significantly impacted the species richness rather than aboveground carbon storage. Soil temperature was significantly associated with belowground carbon storage. These findings provide a new insight which will help us to assess the relationship between plant diversity and ecosystem functioning. They also allow us to understand how vegetation responds to climate change in high-altitudes areas.

Grasses doi: 10.3390/grasses4010009

Authors: Anderson Lopes Pereira José Neuman Miranda Neiva Fabrícia Rocha Chaves Miotto Juliana Silva de Oliveira Alberto Jefferson da Silva Macêdo Josilene Lima Serra Daniel Henrique de Souza Tavares Paulo da Cunha Tôrres Junior Evandro de Sousa da Silva Edson Mauro Santos

The objective was to evaluate the effect of supplementation during three seasons (autumn, winter, and spring) on the productive and reproductive performance of Nellore heifers grazing on Mombaça grass. A total of 28 Nellore heifers were subjected to two supplementation strategies: 15 CP [15% crude protein (CP)] and 18 CP (18% CP). The experimental design was completely randomized in a factorial arrangement (two supplementation strategies and three seasons). A strategy × season interaction effect was observed for height (p = 0.008), with the 15 CP strategy in spring showing a higher average (56 cm) compared to 18 CP (26 cm). Regarding pasture chemical composition, the season significantly influenced quality (p < 0.05), with winter presenting inferior quality. A strategy × season interaction effect was also observed (p < 0.05), with lower averages recorded during winter for the 18 CP strategy in final body weight (FBW) (271.74 kg), total weight gain (TWG) (31.48 kg), and stocking rate (SR) (3.99 animal units per hectare, AU/ha). In reproductive efficiency, the 15 CP strategy achieved a pregnancy rate of 85% compared to 54% for the 18 CP strategy. The 15 CP strategy provided better performance for the heifers, increasing FBW, TWG, SR, and pregnancy rate, with significant results in spring due to improved forage quantity and quality associated with supplementation.

Grasses doi: 10.3390/grasses4010008

Authors: Janessa Kluth Noah G. Davis Samuel A. Wyffels Clayton B. Marlow Lance T. Vermeire Taylre E. Sitz Thomas G. Hamilton Timothy DelCurto

Current management paradigms suggest deferring grazing rangeland for two years post-fire to avoid additional stress on native grass species, but there is little research supporting these recommendations. This study was conducted within and adjacent to the burn area of a wildfire to evaluate the differences in diet quality, botanical composition, and foraging behavior of beef cattle on burned and unburned rangeland in the spring and fall of the year following a fire. Diet composition and masticate samples were collected during 20 min bite-count periods using six ruminally cannulated cows in burned and unburned sites in June and September. Diets differed between burned and unburned sites across seasons, but the differences were most apparent in June. Cattle grazed more selectively on burned sites in June, consuming a higher quality diet dominated by forbs. In September, cattle shifted to grass-dominated diets with fewer differences between burned and unburned sites. This indicates that the nutritional flush on post-fire rangelands may be minimized by the end of the first growing season post-fire. Additionally, in the first spring post-fire, cattle may shift grazing pressure away from vulnerable perennial native grass species to the early-seral forbs, commonly associated with the post-fire environment.

Grasses doi: 10.3390/grasses4010007

Authors: Alice Hand Emily Marsh Carmen Giron Dominguez Abhay Menon Theresa Rubhara Helena McMahon Breda O’Dwyer Paul Holloway James Gaffey

To support the ambitious bioeconomy vision outlined in Ireland’s Bioeconomy Action Plan, there is an urgent need to bring together the necessary stakeholders required to implement this vision. Farmers and other primary producers who oversee the production of sustainable biomass constitute one of the most important categories of stakeholders in the bio-based value chain. To ensure scalable, long-lasting bioeconomy collaboration, it is essential that farmers are involved in developing this bioeconomy vision. The current study provides a mixed-methods approach to co-design a green biorefinery vision with Irish farmers and other key value-chain actors. The selected value chain targeting a medium-scale grass silage biorefinery focused on the production of eco-insulation materials, with protein and biogas co-products for local markets. This was then assessed economically using an economic model, which provided a payback period of five years. To identify suitable sites for deployment of the green biorefinery in rural areas, geographical information systems (GIS) analysis was undertaken, considering various environmental, socio-economic and infrastructural variables, which identified 26 potential sites for deployment of the green biorefinery model in Ireland. This study found that early engagement with and inclusion of the farmers in a co-designed process of innovation and alternative revenue streams for them is essential. While a preferred cooperative-based business model for a grass silage biorefinery was identified in consultation with the multiple stakeholders, further research on its long-term commercial sustainability is proposed as future research.

Grasses doi: 10.3390/grasses4010006

Authors: Jesús Daniela Calvo Tomás Vicente Del Campo Alejandra Antonieta Acuña

The efficient use of water resources is a growing priority in multiple sectors, including the turfgrass industry. Nanobubbles (NB) represent an innovative technology that, by enriching solutions with various gases, offers significant benefits in several industrial areas. In crop irrigation, they have been shown to increase dissolved oxygen in the root zone and thereby boost yields. The objective of this study was to evaluate the impact of the use of oxygen NB in irrigation water on turfgrass quality, considering different levels of water restriction (0%, 30%, and 50% of daily crop evapotranspiration), compared to conventional irrigation. During the summer of 2024, trials were conducted using turf quality indices based on multispectral reflectance and RGB digital image analysis. The results showed that the use of NB allowed for a reduction in irrigation by 50% without compromising turf quality, reaching values similar to treatments without water restriction. In contrast, treatment with the same restriction but without NB (WNB50%) showed a deterioration in quality. This study shows NB as an innovative tool to optimize water use, with great potential for applications in landscape green areas, promote water use efficiency, and reduce the costs associated with irrigation.

Grasses doi: 10.3390/grasses4010005

Authors: Noah G. Davis Sam A. Wyffels Timothy DelCurto

Dormant forage is generally understood to be low-quality, but how and why it changes over the dormant season have not been well studied. Therefore, this study evaluated the changes in the forage quality of bluebunch wheatgrass (Pseudoroegneria spicata) and Idaho fescue (Festuca idahoensis) over the course of the dormant season and in response to concurrent environmental conditions. We collected forage samples every 14 days for two consecutive winters in southwestern Montana, USA. Samples were analyzed for crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF). A suite of environmental metrics was derived from PRISM weather data. Data were analyzed with a linear mixed model and the STATICO ordination method. Crude protein and ADF varied throughout the winter across both years, with CP ranging from 1.9–4.0% and ADF from 37–42%. The differences between species were more pronounced and more consistent in CP. The differences between years were more pronounced in ADF and NDF. Relative temperature explained the most variation in forage quality. Crude protein is positively correlated with short-term warmer temperatures, whereas NDF is positively correlated with longer-term warmer temperatures. This demonstrates that forage quality can change over the dormant season and is influenced by winter weather events.

Grasses doi: 10.3390/grasses4010004

Authors: Chanthy Huot Joshua N. M. Philp Yi Zhou Matthew D. Denton

Soil compaction impedes root exploration by plants, which limits access to nutrients and water, ultimately compromising survival. The capability of roots to penetrate hard soils is therefore advantageous. While root penetration has been studied in various annual crops, the relationships between root growth and root penetration are poorly understood in tropical perennial grasses. This study aimed to compare root penetration capability in 10 tropical perennial forage grasses and identify relationships between root penetration, root diameter and vertical root growth. Root penetration of each species, namely Urochloa (syn. Brachiaria) brizantha cv. Mekong Briz, U. decumbens cv. Basilisk, U. humidicola cv. Tully, U. hybrid cv. Mulato II, U. mosambicensis cv. Nixon, U. ruziziensis cv Kennedy, Panicum coloratum cv. Makarikariense, Megathyrsus maximus (syn. Panicum maximum) cv. Tanzânia, Paspalum scrobiculatum (syn. Paspalum coloratum) cv. BA96 10 and Setaria sphacelata cv Solendar, was evaluated using wax layers of varying resistances, created from a mixture of 40% (1.39 MPa) and 60% (2.12 MPa) paraffin wax, combined with petroleum jelly. Reference root sizes were determined for the grass species by measuring root diameter and root lengths of seedlings grown in growth pouches. Vertical root growth rate for each species was measured in grasses grown in 120 cm deep rhizotrons. Species with greater root penetration at both resistances had significantly higher shoot growth rates (r = 0.65 at 40% wax and 0.66 at 60% wax) and greater root diameters (r = 0.67 at 40% wax and 0.68 at 60% wax). Root penetration was significantly higher in species with greater vertical root growth rate only in the 60% wax treatment (r = 0.82). Root penetration at higher resistance was correlated with the root diameter and rapid vertical root growth of the species. This may indicate a contribution of these traits to root penetration ability. The combination of greater root diameter and root vertical growth rate, as observed in M. maximus, may assist in the identification of perennial forage grasses suitable for agroecosystems challenged by soil compaction and rapidly drying soil surface.

Grasses doi: 10.3390/grasses4010003

Authors: Alex J. Lindsey Marco Schiavon J. Bryan Unruh Kevin Kenworthy

Recently, turfgrass has received scrutiny from the public in many parts of the United States due to the misconception that it has limited benefits and has negative impacts on the environment. These negative impacts are often associated with water and chemical usage during turfgrass maintenance. Even with these ill-advised concerns, turfgrass remains an important component of urban landscapes. Contrary to public opinion, turfgrass has numerous environmental, ecological, economical, social, and societal benefits. This review paper summarizes and highlights the benefits of turfgrass systems.

Grasses doi: 10.3390/grasses4010002

Authors: Siviwe Odwa Malongweni Kaya Mrubata Johan van Tol Mohamed A. M. Abd Elbasit Douglas M. Harebottle

Prosopis glandulosa (Mesquite), an invasive alien tree species, poses major threats to soil health, native vegetation, and biodiversity in South African rangelands. The negative impacts of Prosopis on socio-economic, environmental, and ecological resources outweigh the benefits. Most South African researchers are afraid that if left uncontrolled or poorly managed, it can cause severe land degradation, reduced agricultural productivity, indigenous-species shift, and ultimately the loss of biodiversity. Consequently, this will undermine key sustainable development goals related to food security and environmental conservation. In this review we conducted a systematic review, identifying 309 peer-reviewed articles from Google Scholar and Web of Science, screening and analyzing 98 of these, and ultimately reviewing 34 publications in detail. Three key research gaps were identified: (1) insufficient research focused on Prosopis invasion in South Africa; (2) limited integration and collaboration between the agricultural sector, environmental conservation sector, and governmental bodies; and (3) challenges in policy implementation within invaded areas. The study seeks to address these gaps by highlighting the impact of this alien invasive Prosopis species on land, biodiversity, and overall ecosystem stability. It also investigates policy issues surrounding invasive species and their control. Effective management of Prosopis within the country will not only control the spread but also support the broader objectives of environmental conservation, agricultural sustainability, and socio-economic development.

Grasses doi: 10.3390/grasses4010001

Authors: Glícia Rafaela Freitas da Fonsêca Jamiles Carvalho Gonçalves de Souza Henrique Ednaete Bezerra de Alcântara Náthaly Vitória Santos Almeida Alexandre Campelo de Oliveira Maria Luana da Silva Medeiros Arthur Lucas Júlio Silva Evaristo Jorge Oliveira de Souza

Semi-arid regions present edaphoclimatic limitations for forage production, primarily affecting plant growth and development. Crops adapted to such conditions, like forage sorghum, and nutritional supplementation with nitrogen and molybdenum, can increase forage production. The objective of this study was to evaluate the interaction between nitrogen and molybdenum on the bromatological and structural components of forage sorghum (SF-15) cultivated in a semi-arid environment, with the hypothesis that nitrogen fertilization combined with molybdenum would enhance nitrogen use efficiency in sorghum. The methodology involved a 5 × 2 factorial experiment in a randomized block design (RBD) with increasing doses of nitrogen (urea) (0, 50, 100, 150, 300 kg ha−¹) and two doses of molybdenum (sodium molybdate): 0 and 160 g ha−1, conducted over three cultivation cycles. At the end of each cycle, morphological variables were evaluated, and yield of natural mass (YNM), yield of dry mass (YDM), crude protein production (CPP), and bromatological components were determined. Morphometric characteristics were influenced by the interaction between cycle x nitrogen doses (N) and molybdenum doses (Mo). For productive characteristics, there was an interaction between cycle and nitrogen doses, with the first regrowth cycle and the dosage of 100 kg ha−1 N showing the highest mean. Bromatological components were influenced by the N and Mo interaction. The study confirmed the synergistic effect between nitrogen and molybdenum. It is recommended to use 100 kg ha−1 nitrogen fertilization for an average production of 10 t ha−1 for SF-15 sorghum.

Grasses doi: 10.3390/grasses3040027

Authors: Iris Schröter Niels Püttschneider Marcus Mergenthaler

Agrivoltaics (AV) are expanding worldwide, but knowledge about the perception and acceptance of this approach is far from complete. The aim of the present study was to investigate the visual perception and acceptance of AV systems, focussing on the central research question of whether the type of grassland use influences the visual perception and acceptance of vertical interspace AV. For this purpose, three photo-based pictures of a vertical interspace AV plant were used in a laboratory experiment with 29 participants: the original photo showing the AV plant with grassland only; an edited photo with cattle added and an edited photo with silage bales added. The eye-tracking results showed that additional picture elements (i.e., cattle and silage bales) at least partially attracted visual attention, but did not distract from the technical elements of the depicted AV systems. The analysis of the acceptance ratings indicated relatively stable attitudes towards AV, which could not be easily modulated by depicting different types of grassland use within AV systems. Short-term and limited changes in attitudes towards AV appeared to result from the provision of information and mental engagement with the topic. We recommend carrying out further research based on larger, representative samples and more realistic stimuli of AV systems that would provide a better understanding of visual perception and acceptance than photos alone, such as on-site visits or VR visualisations, to enhance the external validity of the results. We also suggest conducting longitudinal studies to explore possible long-term effects on the public acceptance of AV systems.

Grasses doi: 10.3390/grasses3040026

Authors: Hunegnaw Abebe Yan Tu

This review investigates the impact of saline and alkaline soils on forage biomass yield, nutritive value, and their subsequent effects on animal growth performance, which are critical for sustainable livestock production. Soil salinity and alkalinity, driven by environmental factors and human activities, significantly affect forage yield and quality, with notable consequences for ruminant nutrition. While some forage species exhibit enhanced crude protein (CP) content and improved leaf-to-stem ratios under salt stress, others suffer from reduced growth and biomass yield. Saline-affected forages are often characterized by lower acid detergent fiber (ADF) and neutral detergent fiber (NDF) levels, enhancing their digestibility and making them a potentially valuable feed resource. However, high salinity levels pose significant challenges to consistent forage production in arid and semi-arid regions. Cultivating salt-tolerant forage species has emerged as a promising solution, offering a sustainable approach to addressing the dual challenges of soil salinity and livestock feed shortages. This review emphasizes the need for further research on salinity tolerance mechanisms and the development of resilient forage varieties. By integrating salt-tolerant forages and adopting effective management practices, livestock producers can ensure a reliable and high-quality feed supply while enhancing the growth performance of ruminant animals in salt-affected areas.

Grasses doi: 10.3390/grasses3040025

Authors: Stefan Burkart Solomon Mwendia

This study examines key challenges and opportunities for improving ruminant productivity in East Africa, with a focus on enhancing access to forage seeds critical for livestock systems in Ethiopia, Tanzania, Kenya, Uganda, Rwanda, and Burundi. Despite high potential for increased livestock production, the region faces a significant feed deficit—nearly 40% of annual feed demand remains unmet—due to the limited availability and affordability of forage seeds. The research identifies a critical gap in quality seed access, with many farmers relying on outdated materials. We propose the promotion of recently improved forage varieties and local seed production as a solution to reduce dependence on costly imports and enhance adoption. Our analysis suggests that bridging the forage deficit would require the cultivation of 2 million hectares and the involvement of 1.5 million farmers, highlighting the scale of intervention needed. Additionally, the regional forage seed market presents an economic opportunity, potentially valued at USD 877 million over the next decade, underlining the importance of government policies, the development of seed systems, and market incentives. The study concludes with recommendations for fostering seed production, improving seed distribution, and addressing socio-economic barriers to ensure widespread adoption and enhance livestock productivity in the region.

Grasses doi: 10.3390/grasses3040024

Authors: Oscar Parra-Camara Luis A. Méndez-Barroso R. Suzuky Pinto Jaime Garatuza-Payán Enrico A. Yépez

Heat velocity (Vh) is a key metric to estimate sap flow which is linked to transpiration rate and is commonly measured using thermocouples implanted in plant stems or tree trunks. However, measuring transpiration rates in the Gramineae family, characterized by thin and hollow stems, is challenging. Commercially available sensors based on the measurement of heat velocity can be unaffordable, especially in developing countries. In this work, a real-time heat pulse flux monitoring system based on the heat ratio approach was configured to estimate heat velocity in wheat (Triticum durum L.). The heat velocity sensors were designed to achieve optimal performance for a stem diameter smaller than 5 mm. Sensor parameterization included the determination of casing thermal properties, stabilization time, and time to achieve maximum heat velocity which occurred 30 s after applying a heat pulse. Heat velocity sensors were able to track plant water transport dynamics during phenological stages with high crop water demand (milk development, dough development, and end of grain filling) reporting maximum Vh values in the order of 0.004 cm s−1 which scale to sap flow rates in the order of 3.0 g h−1 comparing to reports from other methods to assess sap flow in wheat.

Grasses doi: 10.3390/grasses3040023

Authors: Jandis Ferreira Nunes de Araujo João Pedro Alves de Souza Santos Luciana Sandra Bastos de Souza Carlos André Alves de Souza Cléber Pereira Alves Alexandre Maniçoba da Rosa Ferraz Jardim Danielle da Silva Eugênio Leonardo Francelino de Souza José Edson Florentino de Morais Wilma Roberta dos Santos Glayciane Costa Gois Fleming Sena Campos Marcos Vinícius da Silva Abelardo Antônio de Assunção Montenegro Thieres George Freire da Silva

The objective of this study was to evaluate the structural characteristics, yield and water use efficiency of forage cactus under daytime and nighttime irrigation in a Brazilian semiarid region. The experiment followed a completely randomized design in a 3 × 2 factorial scheme, with ten replications: three clones of forage cactus (“IPA Sertânia”—IPA, “Miúda”—MIU, “Orelha de Elefante Mexicana”—OEM) and two irrigation schedules (daytime and nighttime). Irrigation was applied once a week using a graduated cylinder. The structural characteristics (i.e., plant height and width, total number of cladode—TNC; cladode number per emergence order—CN1, CN2 and CN3; cladode area—CA; cladode area index—CAI), productive characteristics (fresh mass production per plant—FM and dry mass—DM) and water use efficiency (WUEFM and WUEDM) were obtained from the plant harvests. Our results showed that the irrigation schedules did not lead to significant differences in most of the response variables (p > 0.05), except for the TNC (13.2 und), CN2 (7.4 und) and CAI (1.58 m2 m−2) of MIU. It was observed that OEM presented the highest yield, WUEFM and WUEDM (p < 0.05). Adopting the OEM clone, regardless of the irrigation schedule, is the strategy that achieves the best production.

Grasses doi: 10.3390/grasses3040022

Authors: Yi Zhou Ruey Toh Nasir Iqbal Maarten Ryder Jishun Li Matthew D. Denton

Certain plant species have developed the ability to express biological nitrification inhibition (BNI), suppressing the activity of nitrifying microbes and thereby reducing the conversion of ammonium to nitrate. This study assessed the BNI capacity and the rhizosphere ammonia-oxidizing microbiome of two grass species: the endemic Australian Barley Mitchell grass (Astrebla pectinata) and the introduced koronivia grass (Urochloa humidicola), using soils from both agricultural land and native vegetation. In agricultural soil, koronivia grass exhibited significantly higher BNI capacity compared with Barley Mitchell grass. However, in native soil, this trend was reversed, with Barley Mitchell grass demonstrating a significantly greater BNI capacity than koronivia grass (52% vs. 38%). Koronivia grass significantly altered the composition of the ammonia-oxidizing bacteria community in its rhizosphere, leading to a decrease in the Shannon index and bacteria number. Conversely, Barley Mitchell grass reduced the Shannon index (1.2 vs. 1.7) and population size (3.28 × 107 vs. 7.43 × 107 gene copy number g−1 dry soil) of the ammonia-oxidizing archaea community in its rhizosphere to a greater extent. These findings suggest that Australian Barley Mitchell grass may have evolved mechanisms to suppress soil archaeal nitrifiers, thereby enhancing its BNI capacity and adapting to Australia’s nutrient-poor soils.

Grasses doi: 10.3390/grasses3040021

Authors: Emmanuel Lievio de Lima Véras Gelson dos Santos Difante Alexandre Romeiro de Araújo Denise Baptaglin Montagner Gabriela Oliveira de Aquino Monteiro Carolina Marques Costa Araújo Antonio Leandro Chaves Gurgel Manuel Cláudio Motta Macedo Jéssica Gomes Rodrigues Juliana Caroline Santos Santana

The objective was to evaluate the effects of potassium fertilization on the morphogenetic, structural, and productive characteristics of Panicum maximum (cvs. Tanzania, Quênia, Mombaça, Zuri, Massai, and Tamani). The design was in randomized blocks with four doses of potassium (K) 0, 205, 410, and 820 mg dm−3, divided into 5 applications. The analyzed variables were leaf appearance rate (LAR), leaf elongation rate (LER), stem elongation rate (SER), leaf senescence rate (LSR), leaf life span (LLS), phyllochron (PC), number of live leaves (NLL), final leaf length (FLL), tiller population density (TPD), and forage mass (FM). LAR increased by 0.00216 leaves tiller on day-1 (p = 0.0354) and LER increased by 0.00980 cm tiller on day-1 for each milligram of K (p = 0.0402). There was an increase in FLL of 0.16, 0.08, and 0.07 days for the cultivars Mombaça, Massai, and Tamani, respectively, for each milligram of K applied (p = 0.0034). The TPD of the cultivar Tamani increased linearly by 0.074 tillers/pot for each milligram of K (p = 0.0226), and the cultivar Massai showed a quadratic behavior. The TPD of the other cultivars was not influenced by the increase in the K doses. For forage mass (FM), the cultivars Mombaça and Quênia increased by 0.16 and 0.39 g DM/pot for each milligram of K added to the soil. The cultivars Tanzânia, Zuri, Massai, and Tamani showed maximum point at doses of 261.35, 279.45, 300.57, and 275.86 mg dm−3 K, respectively. Potassium fertilization linearly increased leaf appearance and elongation, with maximum productivity reached at a K dose of 430 mg dm−3, except for the cultivars Mombaça and Quênia, which responded up to a K dose of 820 mg dm−3.

Grasses doi: 10.3390/grasses3040020

Authors: Danielle Ferreira Baffa Tadeu S. Oliveira Alberto Magno Fernandes Michele Gabriel Camilo Ismael N. Silva Elon Souza Aniceto José Ribeiro Meirelles Júnior Elvanio José Lopes Mozelli Filho

This study aimed to investigate the effect of different forage sources and forage-to-concentrate ratios on digestibility, energy concentration, fermentation parameters, and in vitro estimate of methane. The experiment was carried out in a completely randomized design using a 3 × 6 factorial arrangement with three forages varying the chemical composition (pineapple crop waste silage [PS], corn silage [CS], and Tifton hay [TH]) associated with concentrate feed (C) in six combinations, using triplicates for each ratio. We evaluated in vitro digestibility, metabolizable and net energy, pH, redox potential, volatile fatty acids (VFA), and methane production. The in vitro neutral detergent fiber digestibility (IVNDFD) decreased (p = 0.0011) with the inclusion of concentrate. It was also affected by the forage source, but this fact was only observed in CS up to the 50:50 ratio. In TH, this fact occurred from the 80:20 ratio, and this behavior was not observed in the PS. Data on methane production, VFA, and fermentation parameters varied according to forage source and concentrate inclusion. In conclusion, the inclusion of concentrate reduces methane production, increasing the system’s energy contribution. Overall, the different forage sources and the inclusion of concentrate change digestion and fermentation parameters.

Grasses doi: 10.3390/grasses3040019

Authors: Francuois L. Müller Jabulile E. Leroko Clement F. Cupido Igshaan Samuels Nothando Ngcobo Elizabeth L. Masemola Fortune Manganyi-Valoyi Tlou Julius Tjelele

Brachiaria forages are known to be drought-tolerant as mature plants, but no information about drought tolerance at the seed germination stage is currently available. This study aimed to determine the impacts of different temperature and moisture conditions on the seed germination characteristics of five Brachiaria genotypes. Brachiaria seeds were germinated under constant temperatures of 5 °C–45 °C at increments of 5 °C. Within each temperature treatment, five osmotic treatments (0 MPa, −0.1 MPa, −0.3 MPa, −0.5 MPa, and −0.7 MPa) were applied, and germination was recorded daily for 20 days. The results showed that seed germination in all Brachiaria species was significantly negatively impacted (p < 0.05) by osmotic stress as well as by high and low temperatures. For all species, germination only occurred between 15 and 40 °C. Under optimum moisture conditions (0 MPa), the optimum germination temperatures for B. humidicola were 15 to 35 °C, for B. brizantha and B. nigropedata, they were 15 to 20 °C, for B. decumbens, they were 15 to 25 °C, and for the hybrid Brachiaria species, the optimum germination temperature was only 20 °C. In all species, seed germination decreased as moisture conditions became more limiting. Only B. humidicola germinated optimally at a high temperature (35 °C). At these temperatures, the species had more than 82% germination when moisture was not a limiting factor (0 MPa), but at low osmotic stress conditions (−0.1 MPa) at 30 °C, the germination of this species decreased to 67%. In conclusion, the results from this study indicate that the seed germination and early seedling establishment stages of Brachiaria grasses are only moderately tolerant to drought stress. Further work on early seedling responses to temperature and moisture stresses is needed to quantify early seedling responses to these stresses and to develop more detailed planting time guidelines for farmers.

Grasses doi: 10.3390/grasses3040018

Authors: Althieres José Furtado Flavio Perna Junior Rolando Pasquini Neto Adibe Luiz Abdalla Filho Sophia Aparecida Morro Chamilete Patrícia Perondi Anchão Oliveira Paulo Henrique Mazza Rodrigues

Tropical pastures intercropped with legumes have been gaining prominence for increasing the efficiency of livestock production systems when compared to pasture monocultures. Here, our objective was to understand the fermentation processes that tropical grass and legumes underwent when included in ruminant diets, which have previously been found to optimize animal performance while reducing the intensity of enteric CH4 emissions. For this purpose, three areas containing pigeon pea (Cajanus cajan) and Urochloa spp. were sampled. Samples were dried, grounded, chemically analyzed, and included in five proportions (0%, 25%, 50%, 75%, and 100%) of pigeon pea in the diet. The diets were then analyzed using an in vitro fermentation technique. Statistical analysis was performed using SAS statistical software, considering bottles as replicates, and our results suggest that a 25% inclusion of pigeon pea is optimal for balancing CH4 mitigation and fermentation efficiency, highlighting the importance of more studies with this legume due to its benefits, especially as a supplement during drought periods that impact the production and quality of tropical pastures. It is important to consider that pigeon pea’s secondary compounds may have positively modulated the fermentation process and reduced CH4 emissions. However, excessive legume inclusion can negatively affect digestibility and animal health, impairing animal performance and the sustainability of pasture-based production systems.

Grasses doi: 10.3390/grasses3040017

Authors: Mziwanda Mangwane Ignacio Casper Madakadze Florence Veronica Nherera-Chokuda Sikhalazo Dube Mthunzi Mndela Ngoako Letsoalo Tlou Julius Tjelele

Coal mining is known to have negative impacts on the environment, necessitating land rehabilitation after mining activities. Amongst the problems associated with coal mining is the accumulation of acid mine drainage characterized by large amounts of heavy metals and high acidity. The impact of these environmental problems on the ecosystem around mining areas underscores a need to devise strategies that will ensure sustainable restoration of the ecosystem integrity to ensure environmental protection. Of these, treatment of acid mine drainage using calcium sulfate dihydrate, which is subsequently used for irrigation during phytoremediation, holds great promise for restoration of open-cast mines. However, although grasses are used for rehabilitation of coal mined areas, the impacts of treated mine water on the germination, seedling emergence, and plant growth of grasses are not well known. The aim of the study was to evaluate the germination and early seedling growth responses of different forage grasses to treated mine water. Seven forage grass species were selected, with four species represented by two varieties while others were represented by one variety, totaling 11 forage grasses. For each plant entry, 100 seeds were placed in J.R. Petri’s dishes lined with Whatman No. 2 filter paper and watered with distilled and mine water to assess germination. For the seedling establishment experiment, only five species were studied, in which twenty seeds per species were sown in pots containing mine soil and irrigated using distilled and treated mine water. The final germination percentage (FGP), germination rate index (GRI), corrected germination rate index (CGRI), and T50 were determined for the germination trail and total biomass was assessed for the seedling growth trail. The highest FGP for all grasses was attained under controlled conditions, using distilled water, ranging from 38–94%. All grasses germinated when watered using treated mine water and had a FGP ranging from 20–91%. Relative to distilled water, GRI and CGRI were highest only for L. multiflorum cv AgriBoost when seeds were watered using the treated mine water. All grasses watered with treated mine water produced high biomass for the first two weeks, after which biomass production started to decline. Two grasses, Eragrostis curvula cv Ermelo and Lolium multiflorum cv Archie, showed tolerance to treated mine water irrespective of its high electrical conductivity (557 mS∙m−1). Therefore, these grasses could be used in the rehabilitation of coal-mined areas irrigated with treated mine water.

Grasses doi: 10.3390/grasses3030016

Authors: Kristina S. Walker Katy E. Chapman

Irrigation practices that conserve water use have the potential to reduce greenhouse gas (GHG) emissions but may adversely affect turfgrass appearance. The purpose of this study was to identify irrigation practices and N fertilizers that will decrease carbon dioxide (CO2), methane (CH4,), and nitrous oxide (N2O) emissions while evaluating turfgrass color and quality. In both years, supplemental rainfall (SRF) soil moisture content was higher than business as usual (BAU) irrigation and syringing (SYR). Higher soil moisture led to increased fluxes in both soil CO2 and soil N2O. In 2017, the SRF fluxed lower soil CO2 as soil moisture reached levels that restricted respiration. Soil moisture was also an important predictor of soil N2O flux with BAU and SRF having higher soil N2O fluxes. SRF produced the greenest turf from May to July, whereas SRY and SRF produced the greenest turf from August to October in 2016. Both BAU and SRF had the greenest turf in 2017. BAU had the highest turfgrass quality ratings in 2016 followed by SRF and SRY, respectively, whereas in 2017 SRF and SRY had higher turfgrass quality ratings. When adopting water conservation practices to reduce GHG emissions, soil moisture content and site-specific rainfall should be closely monitored to prevent overwatering.

Grasses doi: 10.3390/grasses3030015

Authors: Braian Vogel Lucia Molina César M. Rostagno Ludmila La Manna

Historical sheep farming in the Patagonian drylands has led to reduced grass cover, soil erosion, and shrub encroachment, compromising ecosystem function. Effective restoration requires managing shrub cover, bare soil, and patch connectivity through various strategies. This study evaluates rehabilitation interventions in a grass-steppe ecosystem, comparing grazed and ungrazed areas. Over three years, we tested the following: (a) mechanical shrub cutting with biomass redistribution, and (b) enhancing patch connectivity with Pinus spp. branch piles, alongside controls, in eighteen 5 m × 5 m plots invaded by Mulinum spinosum. Half of the plots were fenced to exclude grazing, resulting in six treatment combinations. We monitored soil properties, vegetation cover, and species composition. The treatments explained twice as much of the variation in community composition as the annual climatic variations (0.26 vs. 0.13). Livestock exclusion increased perennial grass cover more than the grazed plots did (2.14 vs. 1.42 times the initial measure). All treatments reduced the amount of bare soil except the grazed controls. Shrub cutting, especially with grazing, increased the lasting litter coverage by 5–10% and decreased the bare soil equivalently. Organic matter increased except in the non-intervened interpatches (0.95 times). The enclosures with cut shrubs trapped erodible particles, showing a 5% increase. Our study highlights that grazing destabilizes communities, while enclosures stabilize them, with interventions improving soil fertility and mitigating erosion.

Grasses doi: 10.3390/grasses3030014

Authors: Jingbo Yu Xingyu Luo Qingping Zhou Zhou Li Shiyong Chen

Melatonin (MT) is a multifunctional hormone that enhances crop resilience against various abiotic stresses. However, its regulatory mechanism of osmotic tolerance in forage oats (Avena sativa) plants under water-limited scenarios is still unclear. This study aimed to delineate the impact of MT pretreatment on the morphological, physiological, and biochemical functions of oat seedlings under osmotic stress. Our findings demonstrated that exogenous treatment of MT noticeably elevated leaf area while decreasing the root/shoot ratio of oat seedlings subjected to osmotic stress. Osmotic-induced 38.22% or 48.37% decrease in relative water content could be significantly alleviated by MT pretreatment on day 7 or day 14, respectively. MT treatment also significantly mitigated osmotic-induced decreases in photosynthetic parameters including net photosynthetic rate, stomatic conductance, and intercellular CO2 concentration as well as various chlorophyll fluorescence parameters, which could contribute to enhanced accumulations of free proline and soluble sugars in seedlings after being subjected to a prolonged duration of osmotic stress. Furthermore, MT markedly improved antioxidant enzyme activities including superoxide dismutase, ascorbate peroxidase, catalase, and peroxidase along with the accumulation of ascorbic acid contributing to a significant reduction in reactive oxygen species under osmotic stress. In addition, the MT application induced a 978.12%, 33.54%, or 30.59% increase in endogenous MT, indole acetic acid, or gibberellic acid content under osmotic stress but did not affect the accumulation of abscisic acid. These findings suggest that an optimal concentration of MT (100 μmol·L−1) could relieve osmotic stress via improvement in osmotic adjustment, the enzymatic antioxidant defense system, and endogenous hormonal balance, thereby contributing to enhanced photosynthetic functions and growth of oat seedlings under water-limited conditions.

Grasses doi: 10.3390/grasses3030013

Authors: Carlindo Santos Rodrigues Márcia Cristina Teixeira da Silveira Leandro Martins Barbero Salim Jacaúna Sousa Júnior Veridiana Aparecida Limão Guilherme Pontes Silva Sila Carneiro da Silva Domicio do Nascimento Júnior

This study was carried out to characterize the dynamics of forage accumulation during the regrowth of Mulatto grass submitted to rotational grazing strategies. The treatments corresponded to combinations between two pre-grazing conditions (95% and a maximum light interception during regrowth—LI95% and LIMax) and two post-grazing conditions (post-grazing heights of 15 and 20 cm), according to a 2 × 2 factorial arrangement and randomized complete block design, with four replications. Rates of leaf growth (LGR), stems growth (SGR), total growth (TGR), leaf senescence (LSR), grass accumulation (GAR) (kg·ha−1·day−1), and the senescence/canopy growth ratio during different stages of regrowth. There was no difference between the management strategies for TGR. However, a higher GAR was reported for pastures managed with LI95% relative to LIMax, of 161.7 and 120.2 kg DM ha−1·day−1, respectively. Pastures managed with LI95% have a lower SGR in the intermediate and final regrowth period, reflecting the efficient control in the stalks production. On the other hand, in pastures managed, the LIMax showed higher SGR and LSR in the final regrowth phase. Thus, the LAI was higher in pastures managed at LI95% compared to those managed at LIMax, of 163.9 and 112.7 kg DM ha−1·day−1, respectively. Mulatto grass pastures, which were managed at LI95% pre-grazing, corresponded to approximately 30 cm in height, showed higher LAI, and ensured a low SGR throughout the regrowth period, constituting a more efficient management strategy.

Grasses doi: 10.3390/grasses3030012

Authors: Leonard M. Lauriault Murali K. Darapuneni Gasper K. Martinez

In a continued search for legumes to grow with forage sorghum (FS) [Sorghum bicolor (L.) Moench] in semi-arid environments, studies in 2019 and 2022 at New Mexico State University Rex E. Kirksey Agricultural Science Center at Tucumcari, NM USA, evaluated FS mixed with cowpea [Vigna unguiculata (L.) Walp.], lablab (Lablab purpureus L.), both previously evaluated, and a native legume, big-pod sesbania (Sesbania macrocarpa), for yield and nutritive value in four randomized complete blocks each year. At harvest legume proportions of approximately 15% of the dry matter yield, there were no differences in the yield (mean = 15.97 Mg ha−1, p > 0.40) or land equivalency ratio between sole FS and any mixture or among mixtures; however, the crude protein of FS+Lablab was greater than sole FS, with FS+Cowpea and FS+Sesbania intermediate (67, 77, 87, and 79 g kg−1 for sole FS, FS+Cowpea, FS+Lablab, and FS+Sesbania, respectively; 5% LSD = 14). The neutral detergent fiber digestibility of FS+Sesbania was less than all other treatments (p = 0.0266). Although the sesbania did not improve forage yield or nutritive value when grown with FS and harvested near sesbania maturity, perhaps growing with a shorter season grass and harvesting earlier may show benefit, as sesbania’s nutritive value is known to be greater at earlier stages.

Grasses doi: 10.3390/grasses3030011

Authors: Nauara Moura Lage Filho Airton da Conceição dos Santos Suianne Lorena da Silva e Silva João Victor Costa de Oliveira Vitor Hugo Maués Macedo Antônio Marcos Quadros Cunha Aníbal Coutinho do Rêgo Ebson Pereira Cândido

Nitrogen fertilization is one of the main management strategies for continuous pasture management with high productivity. We examined the effects of nitrogen fertilization on the morphogenic, structural, and tillering dynamic characteristics of Tanzania grass in the Amazon region in the state of Pará, Brazil. The study was conducted using a randomized block design with six treatments (0, 100, 200, 300, 400, and 500 kg N ha−1 year−1) and five replicates. The treatments were performed during the rainy season in 2016 and 2017 using urea as the nitrogen source. The leaf elongation rate was increased by 68.5% compared with that of the control treatment (p < 0.01). The leaf appearance rate and number of alive leaves increased with higher doses of nitrogen (p < 0.01, each). The regrowth period was reduced by approximately 13 days under 500 kg N ha−1 (p < 0.01), thus providing more production cycles. Nitrogen fertilization was also associated with a higher tillering rate (p < 0.01); however, the rate of this increase decreased with increasing nitrogen dose. Higher nitrogen doses thus improved the development of Tanzania grass; however, this became less pronounced at doses < 300 kg N ha−1.

Grasses doi: 10.3390/grasses3030010

Authors: Janessa Kluth Samuel Wyffels Jed Eberly Lance Vermeire Clayton Marlow Timothy DelCurto

In the United States, rangelands comprise 30% of the total land cover and serve as a valuable resource for livestock, wildlife, water, and recreation. Rangelands vary in climate and are often subject to disturbances like drought and wildfire. Historic wildfire trends have indicated an increase in wildfire size and frequency, raising societal and ecological concerns about the management of these lands, both pre- and post-wildfire. While there has been investigation into the effects of grazing prior to a wildfire on fire severity and plant mortality, there is limited research related to grazing post-wildfire even though current management paradigms suggest deferring grazing rangeland for two years after a wildfire to avoid additional stress on native plant species. Based on the diversity found across rangeland ecotypes and history with wildfire, the two-year deferment recommendation may need to be reconsidered for some ecosystems. Species found in perennial bunchgrass rangelands like Pseudoroegneria spicata (bluebunch wheatgrass) and Festuca idahoensis (Idaho fescue) may be less susceptible to post-fire grazing than initially thought, necessitating the need for research into different rangeland ecosystems.

Grasses doi: 10.3390/grasses3030009

Authors: Judit Házi Dragica Purger Károly Penksza Sándor Bartha

The focus of our study was the changes in the composition of semi-natural dry grasslands in Hungary. Maintaining the favorable condition of grasslands is not only important from a theoretical nature conservation point of view, but it also has important economic implications. Since these valuable habitats were created with the help of humans, their preservation also requires active treatment. Our current experiment was aimed at investigating the suppression of tall grass, Calamagrostis epigejos L. Roth. In Hungary, in the Cserhát Mountains, eight permanent plots were mown twice a year. We surveyed the vegetation twice a year between 2001 and 2011. The effects of treatment were studied with repeated measures analysis of variance (ANOVA). After 10 years, the C. epigejos cover of the mown plots decreased significantly, from the initial average of 62.38 to 7.50%. Surprisingly, we noticed a decrease in the control plots as well. While percentage cover of C. epigejos decreased in all plots, the decrease was significantly stronger in the mown plots. Regular treatment caused an increase in the number of species and diversity. Species richness increased continuously in both treatment types, which indicates the combined effect of vegetation succession and treatment. The biomass growth of other Poaceae and Fabaceae species, which are important from a grassland management perspective, was also facilitated by mowing. Our results allow us to conclude that long-term regular mowing is recommended for preservation from the perspective of the richness and variety of grassland management functional groups and the functioning of the ecosystem in semi-arid regenerating grasslands.

Grasses doi: 10.3390/grasses3020008

Authors: Gabriela Ramírez-Ojeda Edith Ramírez-Segura Luis Ángel Barrera-Guzmán Abieser Vázquez-González

Arid and semi-arid areas are highly productive ecosystems that have a great diversity of species, among which grasses stand out. These species have ecological, environmental, and economic importance. The objective was to identify the ecological descriptors of 15 native species of grasses and diversity patterns through multivariate analysis techniques (principal component analysis, PCA, and cluster analysis, CA), in addition to identifying potential distribution areas (current and future) and regions of high and low diversity from 3841 accessions and 21 climatic variables. Among the main results, the extreme values, coefficient of variation, and median for each species could be determined. PCA determined that, with 10 variables, it was possible to explain 54.36% of the variation between the analyzed species. CA resulted in the formation of four statistically significant groups, with specific climatic characteristics. Regarding potential distribution areas and climate change, a reduction in distribution is expected (2050) on most of the current surface, with a possible opportunity zone in the north of the country. Finally, two hotspots (high diversity areas) and four coldspots (low diversity areas) were identified among the analyzed species. These results can be used to create strategies for sustainable use and the conservation of these resources.

Grasses doi: 10.3390/grasses3020007

Authors: Alexander Hernandez Kevin Jensen Steve Larson Royce Larsen Craig Rigby Brittany Johnson Claire Spickermann Stephen Sinton

Forage yield estimates provide relevant information to manage and quantify ecosystem services in grasslands. We fitted and validated prediction models of forage yield for several prominent grasses used in restoration projects in semiarid areas. We used field forage harvests from three different sites in Northern Utah and Southern California, USA, in conjunction with multispectral, high-resolution UAV imagery. Different model structures were tested with simple models using a unique predictor, the forage volumetric 3D space, and more complex models, where RGB, red edge, and near-infrared spectral bands and associated vegetation indices were used as predictors. We found that for most dense canopy grasses, using a simple linear model structure could explain most (R2 0.7) of the variability of the response variable. This was not the case for sparse canopy grasses, where a full multispectral dataset and a non-parametric model approach (random forest) were required to obtain a maximum R2 of 0.53. We developed transparent protocols to model forage yield where, in most circumstances, acceptable results could be obtained with affordable RGB sensors and UAV platforms. This is important as users can obtain rapid estimates with inexpensive sensors for most of the grasses included in this study.

Grasses doi: 10.3390/grasses3020006

Authors: Zinhle Mashaba-Munghemezulu Lwandile Nduku Cilence Munghemezulu George Johannes Chirima

Grasslands cover approximately 40% of the Earth’s surface. Thus, they play a pivotal role in supporting biodiversity, ecosystem services, and human livelihoods. These ecosystems provide crucial habitats for specialized plant and animal species, act as carbon sinks to mitigate climate change, and are vital for agriculture and pastoralism. However, grasslands face ongoing threats from certain factors, like land use changes, overgrazing, and climate change. Geospatial technologies have become indispensable to manage and protect these valuable ecosystems. This review focuses on the application of Google Earth Engine (GEE) in grasslands. The study presents a bibliometric analysis of research conducted between 2016–2023. Findings from the analysis reveal a significant growth in the use of GEE and different remote sensing products for grassland studies. Most authors reported grassland degradation in most countries. Additionally, China leads in research contributions, followed by the United States and Brazil. However, the analysis highlights the need for greater involvement from developing countries, particularly in Africa. Furthermore, it highlights the global distribution of research efforts, emphasizes the need for broader international participation.

Grasses doi: 10.3390/grasses3020005

Authors: Eduardo André Ferreira Joadil Gonçalves de Abreu Wininton Mendes da Silva Danielle Helena Müller Dalilhia Nazaré dos Santos Cassiano Cremon Oscarlina Lúcia dos Santos Weber Aaron Kinyu Hoshide Daniel Carneiro de Abreu Maybe Lopes Gonçalves José Advan Pereira Pedrosa Júnior

Gelatin industry residues are increasingly used as fertilizer and soil conditioner. However, correct residue dosage is critical for grass development and minimizing environmental impacts. This randomized block design study determined adequate dosage of mixed gelatin sludge (MGS) for Marandu grass production in wet/dry seasons in Brazil. Five MGS levels (0–200% of required nitrogen) were compared to mineral fertilizer. Agronomic/productivity characteristics, bromatological composition, macro/micronutrient composition of leaves, and soil chemical attributes were evaluated. Agronomic/productivity characteristics were influenced by MGS dose in both dry/rainy seasons, except for leaf blade pseudostem ratio and percentage of leaves/pseudostem. Bromatological composition was influenced by MGS doses in dry/rainy seasons except for dry/mineral material quantities. Marandu leaf tissue chemical composition was significantly influenced by MGS dose, except for potassium, boron, and iron. Chemical composition of four soil layers between 0 and 50 cm influenced MGS dose, except for pH, organic matter, magnesium, copper, manganese, and zinc. GMS dose for Marandu production should be 200% of nitrogen requirement. MGS application increased productivity/quality of Marandu grass. Macronutrients (nitrogen, phosphorus) and micronutrients (calcium, magnesium, sulfur, copper, and zinc) increased in Marandu grass and in the soil (calcium, sulfur, and sodium). The increased sodium level was not limiting.

Grasses doi: 10.3390/grasses3010004

Authors: Paolo Rivaldo Medina Quispe Marco Aurelio Arizapana-Almonacid Marcelo Daniel Nosetto

The high-Andean grasslands of Peru provide a wide range of goods and services, not only locally, but also regionally and globally. However, land-use change and global warming are threatening these ecosystems, of which soil organic carbon (SOC) is a key element affecting their sustainability. In this study, we have analyzed the variation of SOC stocks to a depth of 20 cm in 16 paired cropland and grassland sites located in the Sullccapallcca stream micro-watershed (elevation > 3600 m.a.s.l., Ayacucho, Peru). We have also analyzed the environmental controls on the SOC stocks and their variation with land-use change. We found that the studied high-Andean grasslands store high SOC contents (247 Tn SOC ha−1), whose spatial variability was partially explained by the slope of the terrain (r2 = 0.26, p < 0.05). Despite the higher NDVI, the conversion of these grasslands into croplands decreased the SOC stock by 39 Tn SOC ha−1 on average, a decrease that was more pronounced when the initial SOC content of the grassland was higher (r2 = 0.60, p < 0.05). This study provides the first evidence of the effects of land-use change on the SOC in the region, although the mechanisms involved still need to be investigated.

Grasses doi: 10.3390/grasses3010003

Authors: Gustavo Daniel Vega-Britez Marciana Retore Allison Manoel de Sousa Adrielly Lais Alves da Silva Carolina Marques Costa Carla Giselly de Souza Marcio Rodrigues de Souza Fernando Miranda de Vargas Junior

In Brazil, grazing is the main or only source of food for livestock. The appropriate combination of supplementation with concentrate in a lamb’s diet on pasture is an alternative that can be explored to use natural resources to produce quality meat. The aim of the current study was to evaluate the effects of different supplementation levels (0%, 1.5%, and 3% of BW) on the intake, performance, and production costs of lambs grazing on Aruana (Megathyrsus maximus) and Marandu (Brachiaria brizantha) grasses. Thirty-six non-castrated male Suffolk lambs (22.54 ± 2.72 kg) were used. The lambs were evaluated for nutrient intake and digestibility, such as dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and consumption in relation to body weight (% BW), in addition to the average daily gain (ADG), body condition score (BCS), and hot carcass weight (HCW), as well as the rising production cost of each system. The dry matter of the green leaf blades was influenced by the pasture type (p < 0.05), producing 1503.6 vs. 2977.4 kg/ha of Aruana and Marandu grasses, respectively. The concentrate supplementation level influenced the type of pasture (p < 0.05). A higher consumption of DM, CP, NDF, and organic matter was registered for the supplemented animals (p < 0.05) and on Aruana grass. The intake in relation to body weight was significantly influenced by the concentrate levels (p < 0.05). The empty body weight and HCW were significantly influenced by the supplementation levels (p < 0.05). The ADG and feed conversion (FC; kg DM/ADG) were influenced by the supplementation levels and type of pasture. The BCSs differed between the concentrate levels (p < 0.05). The supplementation improved dry matter digestibility. The ADG and FC were superior in the supplemented animals, with an advantage for those grazing on Aruana grass. The slaughter ADG was also higher in the supplemented animals. The lambs’ pasture comprising Aruana grass with 1.5% BW of concentrate supplementation showed improved production and economic results.

Grasses doi: 10.3390/grasses3010002

Authors: Andressa Radtke Baungratz Leonardo Piffer de Borba Bruna Martins de Menezes Jean Lucas Macari Porsch Tiago Venturini Rusbel Raúl Aspilcueta Borquis Eduardo Eustáquio Mesquita Ériton Egídio Lisboa Valente Vicente de Paulo Macedo

The objective was to characterize the nutrient and mineral composition of M. maximus cv Aruana grazed by lambs in a silvopastoral system or full sun with added nitrogen. The treatments are: (1) Aruana grazed in full sun with nitrogen fertilization, (2) Aruana grazed in full sun without nitrogen fertilization, (3) Aruana grazed in a silvopastoral system with nitrogen fertilization and (4) Aruana grazed in a silvopastoral system without nitrogen fertilization. The nutrient dynamics, urinary excretion of N and the amount returned of the nutrient were determined from four sheep in a Latin square experimental design; the analysis of the mineral composition of the leaves and stalks of the grass was carried out by collecting samples from the plots used, totaling six in each treatment evaluated. The silvopastoral system provided high levels of P and K in forage plants. Urinary N excretion and urine mineral contents were influenced by the systems evaluated and the use of N fertilizer. N did not show differences for leaves and canes.