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Context: Using forage grass species with complementary growth and resource-use strategies to enhance forage plant diversity in pastures may be an alternative to traditional monocultures in tropical regions. Aims: This study aimed to determine whether a mixture of three perennial tropical forage grasses (Andropogon gayanus cv. Planaltina, Panicum maximum cv. Massai, and Brachiaria brizantha cv. BRS Piatã) could be an alternative to enhance herbage intake rates relative to their respective monocultures. Methods: The treatments corresponded to three perennial tropical forage grasses cultivated as monocultures and as a mixture composed of all three species. Defoliation management corresponded to a pre-cutting height of 35 cm and post-cutting height of 17.5 cm. Key results: The botanical composition of the mixture was dynamic throughout the experimental period, with variations in the proportion of species across seasons. The upper half of the canopy predominantly comprised leaves for all treatments. The canopy structure of the mixture allowed for greater herbage intake rates than monocultures during winter/early spring. Andropogon gambagrass showed lower herbage intake rates than the other treatments. Conclusions: The findings of this study indicate that it is possible to combine tropical forage grass species without compromising canopy structure and grazing animal responses, compared with single-species grass pastures. Implications: The selection of forage species for mixed pastures should consider their phenological cycle, growth, and resource-use strategies to achieve temporal complementarity and provide an optimal grazing environment for animals throughout the year. Increasing pasture biodiversity using forage grass species with complementary traits may be an alternative to traditional monocultures in tropical regions. This study investigated the relationship between pasture characteristics and herbage intake, indicating that combining tropical forage grass species is possible without compromising pasture dynamics and grazing animal responses. By optimizing forage diversity, we highlight the importance of species selection and seasonal complementarity for maintaining pasture structure and providing an optimal grazing environment for animals throughout the year. [ABSTRACT FROM AUTHOR]

This article examines the resilience of warm-season (C4) perennial grasses in challenging environmental and management conditions. C4 grasses are crucial for livestock nutrition in tropical and subtropical regions, and climate change may benefit their growth. The article discusses the anatomical and morphological differences that affect the resilience of C4 grasses to management practices. It also explores the distribution and physiological mechanisms of C4 grasses, as well as the impact of nitrogen management and defoliation on their growth and persistence. The article emphasizes the ability of C4 grasses to recover after grazing through the allocation of photosynthate and the storage of carbon and nitrogen. It also highlights the importance of proper soil nutrient and grazing management for maximizing forage production and reducing greenhouse gas emissions. [Extracted from the article]

A two‐year experiment assessed herbage production and above‐ and below‐ground characteristics of a highly productive monoculture ('BRS Zuri' guineagrass [Panicum maximum Jacq.]) and two mixtures of three grasses (Mixture 1: 'BRS Zuri' guineagrass, 'BRS Xaraés' palisadegrass [Brachiaria brizantha Stapf.], and 'Basilisk' signalgrass [Brachiaria decumbens Stapf.]; Mixture 2: 'BRS Quênia' guineagrass [Panicum maximum Jacq.], 'Marandu' palisadegrass [Brachiaria brizantha Stapf.], and 'BRS Paiaguás' palisadegrass [Brachiaria brizantha Stapf.]), cultivated in the Brazilian tropical savanna. Mixtures 1 and 2 were subjected to two grazing intensities (removal of 40 or 60% of pre‐grazing height) and 'BRS Zuri' guineagrass monoculture was defoliated to a single grazing intensity of 50%. Treatments were randomly assigned to fifteen 0.25‐ha plots and managed under intermittent stocking by cattle. Herbage accumulation rate was similar among pastures and years (p >.1). The root mass in the tussocks did not differ (p >.1), with mean values ranging between 0.62 to 1.81 kg DM m−2. Root density in the tussock interspaces was greater in the mixtures (p <.001), regardless of seasons (p =.405) and years (p =.292). The mixtures were dominated by guineagrass (70%) and palisadegrass (30%) at the end of the experiment, with the population of 'Basilisk' and 'BRS Paiaguás' being completely suppressed throughout the experimental period. Mixing guineagrass and brachiariagrasses can be an alternative to the traditional pastoral systems in the tropics, as it does not compromise herbage production and presents a capacity to produce more roots than a very productive monoculture of 'BRS Zuri' guineagrass. [ABSTRACT FROM AUTHOR]

Infestations of the exotic perennial Spotted knapweed ( Centaurea maculosa Lam.) hinder the restoration and management of native ecosystems on droughty, infertile sites throughout the Midwestern United States. We studied the effects of annual burning on knapweed persistence on degraded, knapweed-infested gravel mine spoils in western Michigan. Our experiment included 48, 4-m2 plots seeded to native warm-season grasses in 1999 using a factorial arrangement of initial herbicide and fertility treatments. Beginning in 2003, we incorporated fire as an additional factor and burned half of the plots in late April or May for 3 years (2003–2005). Burning increased the dominance of warm-season grasses and decreased both biomass and dominance of knapweed in most years. Burning reduced adult knapweed densities in all 3 years of the study, reduced seedling densities in the first 2 years, and reduced juvenile densities in the last 2 years. Knapweed density and biomass also declined on the unburned plots through time, suggesting that warm-season grasses may effectively compete with knapweed even in the absence of fire. By the end of the study, mean adult knapweed densities on both burned (0.4-m2) and unburned (1.3-m2) plots were reduced to levels where the seeded grasses should persist with normal management, including the use of prescribed fire. These results support the use of carefully timed burning to help establish and maintain fire-adapted native plant communities on knapweed-infested sites in the Midwest by substantially reducing knapweed density, biomass, and seedling recruitment and by further shifting the competitive balance toward native warm-season grasses. [ABSTRACT FROM AUTHOR]

Warm-season grasses and legumes have the potential to provide forage throughout the Mediterranean summer when there are high temperatures and low rainfall and when cool-season grasses become less productive. Twenty-nine non-native, warm-season pasture species (twenty-three grasses and six legumes) were assessed for their adaptability to the coastal plain of southern Italy in terms of their productivity and nutritional quality. The investigated species were compared with two reference species widely used in a Mediterranean environment: a grass ( Festuca arundinacea) and a legume ( Medicago sativa). The species differed in their phenological and biological characteristics, i.e. start of vegetative resumption, first flowering and cold resistance, from each other and from the control species. From the second year after establishment, warm-season perennial grasses had high dry-matter (DM) yields and, in many cases, a more than adequate nutritional quality. As for legumes, the control, M. sativa gave the best results in all the investigated characters. Among the grasses, seven species ( Chloris gayana, Eragrostis curvula, Panicum coloratum, Paspalum dilatatum, Pennisetum clandestinum, Sorghum almum, Sorghum spp. hybrid) had DM yields greater than the control species and had their maximum growth during the hottest period of the year, when F. arundinacea, the control grass species, was dormant. Eragrostis curvula had the highest annual DM yield (21·1 t ha−1) and P. clandestinum provided the best combination of agronomic and yield characteristics which were similar to those of M. sativa. The seven above-mentioned species have the potential to supply hay or grazing and contribute to broadening and stabilizing the forage production calendar in Mediterranean-type environments. [ABSTRACT FROM AUTHOR]