Grasses, Volume 5, Issue 3 (September 2026) – 7 articles

This study hypothesized that the combination of limestone and gypsum could promote higher pasture yield and affect soil biological properties, such as microbial biomass and enzymatic activity, and alter the population of Bacillus within a pasture system with U. brizantha. A factorial design was employed with two treatments—without and with lime (0 and 1.6 ton ha⁻¹)—and four gypsum doses (0, 0.5, 1.0, and 2.0 ton ha⁻¹) in experimental field plots. Six successive cuts were made in the pasture, and at the end, soil samples were analyzed for microbial biomass, enzymatic activity, and the putative Bacillus spp. community. The association of gypsum application with liming modified soil microbial activity attributes. It was found that only the application of gypsum reduced the microbial biomass and increased the concentration of putative Bacillus spp. in the soil, which correlated positively with increased crop yield, especially with the higher gypsum dose applied. The combined use of limestone and gypsum did not alter the microbial biomass and showed the best performance in increasing yield with the lowest dose of gypsum applied. In both cases evaluated, with and without the use of gypsum in conjunction with liming, it may be possible to achieve significant increases in biomass accumulation in pasture. Full article

Chloris gayana Kunth is a cultivated forage with worldwide distribution, based on its wide environmental adaptability. This review addresses some of the recent findings on C. gayana abiotic stress tolerance resulting from field or controlled conditions trials, focusing on salinity and alkalinity, drought, heat, and water excess. Management of the species under restraining environments is considered—a topic that most published information has concentrated on since a comprehensive review that was published in 2004. The main novel findings since then refer to the growing relevance role C. gayana is adopting in saline and alkaline soil amelioration, either through its association with mycorrhizal fungi or with trees in silvopastoral systems. This key trend is highlighted as a promising area for the development of sustainable production practices. Research gaps are identified. Among them, the development of standardized methodology guidelines for cultivar evaluation to guide adoption decisions and breeding efforts to improve its nutritive value under stress conditions. Tools for molecular intervention of the species that have become available since the previous reviews are also mentioned. Full article

This study investigated the effects of controlled burns on biomass dynamics and fire behavior in areas of stricto sensu grassland in southern Brazil. The experiment consisted of conducting controlled burns in three experimental plots divided into five subplots, with data collection on fire behavior (rate of spread, fireline intensity, residence time, and heat released) followed by monitoring of vegetation recovery over 19 months. To assess the influence of fire on biomass increase, the Gompertz model was fitted, correlating the Absolute Growth Rate (AGR), the time to peak productivity and the time at which the growth curve reaches 95% of the asymptote with the fire behavior variables. The results demonstrated that low-intensity controlled burns were effective in reducing fuel load. Correlation analysis indicated that fire behavior variables had little influence on the rate of vegetation recovery, suggesting that the ecosystem tolerates low-severity disturbances well. The Gompertz model showed a satisfactory fit (R² = 0.86 for total biomass), proving to be a useful tool for management. It is concluded that the use of low-intensity prescribed burns is a viable and safe practice for protected areas. Full article

Methods capable of inferring the nutritional requirements of forage cultivars from related genotypes may help generate preliminary fertilization recommendations when experimental information is limited. This study evaluated whether model identity analysis can be used to infer the nitrogen requirement of Mulato II hybrid grass from the response patterns of its progenitor species, Urochloa brizantha cv. Marandu and Urochloa decumbens cv. Basilisk. A greenhouse experiment using pots filled with an Oxisol was conducted using a completely randomized design in a 3 × 5 factorial arrangement, with three grasses and five nitrogen doses (0, 100, 200, 300, and 400 mg dm⁻³). Forage production, tiller density, and nutritive value were evaluated during establishment and regrowth phases. Linear and quadratic regressions were fitted, and significant models were compared using model identity tests. When model differences were detected, intercepts and parameters were further compared using F-tests. In both establishment and regrowth phases, Mulato II showed response patterns similar to Urochloa brizantha for most evaluated variables, with model identity observed except for tiller number and crude protein concentration. In contrast, Mulato II differed from Urochloa decumbens for all measured traits. Therefore, under the greenhouse conditions evaluated, the nitrogen requirement of Mulato II is more closely related to that of Urochloa brizantha, demonstrating the potential of model identity analysis as a tool for generating preliminary fertilization recommendations for forage cultivars from related genotypes before field validation. Full article

Nitrogen fertilization is widely recognized as a key factor influencing tropical grass productivity; however, its effectiveness may vary according to pasture developmental stage and management practices. This study evaluated the effects of five nitrogen rates (0, 75, 150, 225, and 300 kg ha⁻¹) and two post-cutting residual heights (20 and 30 cm) on the productive, morphological, and nutritional characteristics of Aruana grass (Megathyrsus maximus cv. Aruana) under irrigated conditions. Treatments were arranged in a randomized complete block design with a split-plot structure. Nitrogen was applied as urea in three split applications following simulated grazing events. Herbage mass, dry matter yield, morphological composition, chemical composition, and in vitro dry matter digestibility were evaluated. No interaction was detected between nitrogen fertilization and residual height. Nitrogen fertilization did not affect forage production, morphological composition, chemical composition, or digestibility under the conditions of this study. Residual height influenced forage accumulation, with greater herbage mass and dry matter yield observed at 20 cm than at 30 cm (p = 0.006), without affecting forage quality. These preliminary findings indicate that residual height may be an important factor affecting forage accumulation in irrigated Aruana grass during pasture establishment. Additional studies conducted over multiple growing seasons and environmental conditions are required before definitive management recommendations can be made. Full article

Silages produced from different forage species exhibit substantial variability in chemical composition, digestibility, and fermentation characteristics, which may influence forage quality and preservation efficiency in livestock systems. This study evaluated the nutritional and fermentative variability of silages produced from six forage species (Zea mays L., Sorghum bicolor L., Medicago sativa L., Helianthus annuus L., Cenchrus purpureus, and Saccharum officinarum L.) using multivariate analytical approaches. A database comprising 237 observations, obtained from 24 independent ensiling experiments, was analyzed. Chemical composition, fermentative parameters, and in vitro dry matter digestibility were evaluated through principal component analysis (PCA), canonical discriminant analysis (CDA), and Pearson correlation analysis. Significant differences among forage species were detected (p < 0.05). PCA explained 76.2% of the total variance in the chemical dataset and 85.1% in the fermentative dataset, revealing clear multivariate patterns among silage types. Chemical composition traits provided greater discrimination among silages than fermentative variables, particularly through differences in fiber fractions, soluble carbohydrates, digestibility, and buffering capacity. Corn and sorghum silages were associated with greater starch availability and favorable fermentation profiles, whereas elephant grass and sugarcane exhibited higher fiber concentrations. Alfalfa showed greater crude protein concentration and digestibility, while sunflower was characterized by elevated lignin concentration. Overall, multivariate analyses provided an integrated interpretation of nutritional and fermentative relationships among silages, highlighting species-specific responses to ensiling and their implications for forage conservation and livestock production systems. Full article

Sweet potato (Ipomoea batatas (L.) Lam.) aerial biomass has potential as an alternative forage resource for ruminants in semi-arid regions; however, the fermentative behavior of different genotypes remains poorly understood. This study evaluated the fermentation profile, nutrient losses, and chemical composition of silages produced from the aerial parts of ten sweet potato accessions cultivated under agroecological conditions. Wilted biomass from each accession was pooled, homogenized, and ensiled in four mini-silos used as subsamples for fermentation characterization. Hierarchical clustering identified two distinct groups, indicating clear genotype-dependent variation in silage performance. Accessions BGH-UNIVASF 8 and 16 showed superior fermentation efficiency, characterized by greater dry matter recovery, lower effluent and gas losses, and more stable fermentation profiles. In contrast, several high-yielding accessions exhibited greater fermentation losses, indicating a trade-off between biomass productivity and preservation efficiency. Total digestible nutrients varied among accessions but were not consistently associated with fermentation quality. Overall, the results demonstrate that silage quality in sweet potato is strongly genotype-dependent and highlight the importance of integrating agronomic, nutritional, and fermentative traits when selecting accessions for silage production under semi-arid conditions. Full article