Grasses, Volume 4, Issue 1 (March 2025) – 12 articles

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article