RESUMO.- Os campos naturais apresentam estacionalidade na sua produção forrageira, a qual pode ser atenuada com a introdução de espécies de estação fria através de semeadura direta, aumentando a produção forrageira no inverno. Durante quatro anos, conduziu-se um experimento de semeadura direta de forragem de inverno, sobre campo nativo, em um Argissolo Vermelho-Amarelo, de textura superficial arenosa do norte do Uruguai. .-.-.-.-.-.-.-.-. ABSTRACT.- Natural grasslands have great seasonal fluctuation of forage production.

RESUMO.- Os campos naturais apresentam estacionalidade na sua produção forrageira, a qual pode ser atenuada com a introdução de espécies de estação fria através de semeadura direta, aumentando a produção forrageira no inverno. Durante quatro anos, conduziu-se um experimento de semeadura direta de forragem de inverno, sobre campo nativo, em um Argissolo Vermelho-Amarelo, de textura superficial arenosa do norte do Uruguai. .-.-.-.-.-.-.-.-. ABSTRACT.- Natural grasslands have great seasonal fluctuation of forage production.

Grassland biomes provide valuable ecosystem services, including nutrient cycling. Organic phosphorus (Po) represents more than half of the total P in soils. Soil microorganisms release organic P through enzymatic processes, with alkaline phosphatases, acid phosphatases and phytases being the key P enzymes involved in the cycling of organic P.

High stocking rate livestock management has determined the decline of native species of high forage value as Bromus auleticus Trin ex Nees in the Campos region of the Rio de la Plata grasslands. The species has some agronomic and ecological characteristics that define it as of high potential to be reintroduced in degraded natural grasslands. However, Bromus auleticus has not been sufficiently described, since commercial seeds and information regarding the establishment phase are scarce.

ABSTRACT.- Cynodon dactylon is one of the five most important invasive alien species worldwide. It is the invasive alien species with the broadest distribution range in Uruguay, and its expansion is frequently associated with disturbances. Since natural grasslands are facing processes of productive intensification, C. dactylon represents a threat as it could displace native species. However, the mechanisms that explain its invasion success remain unclear. The objective of this study was to analyse interspecific interactions under low nutrient conditions between C.

ABSTRACT.- Cynodon dactylon is one of the five most important invasive alien species worldwide. It is the invasive alien species with the broadest distribution range in Uruguay, and its expansion is frequently associated with disturbances. Since natural grasslands are facing processes of productive intensification, C. dactylon represents a threat as it could displace native species. However, the mechanisms that explain its invasion success remain unclear. The objective of this study was to analyse interspecific interactions under low nutrient conditions between C.

Many temperate grasses are both hyper-accumulators of silicon (Si) and hosts of Epichloë fungal endophytes, functional traits which may alleviate environmental stresses such as herbivore attack. Si accumulation and endophyte infection may operate synergistically, but this has not been tested in a field setting, nor in the context of changing environmental conditions. Predicted increases in atmospheric CO2 concentrations can affect both Si accumulation and endophyte function, but these have not been studied in combination.

ABSTRACT.- Leaf rust (LR) of bread wheat (Triticum aestviumL.), caused by the fungus Puccinia triticinaEriks, is one of the most important diseases in Paraguay, the Southern Cone and worldwide. The economic importance of the disease is clear considering that two or morefungicide applications are necessary to control itinsusceptible cultivars. The best strategy for the management of this disease is through genetic resistance.

Many temperate grasses are both hyper-accumulators of silicon (Si) and hosts of Epichloë fungal endophytes, functional traits which may alleviate environmental stresses such as herbivore attack. Si accumulation and endophyte infection may operate synergistically, but this has not been tested in a field setting, nor in the context of changing environmental conditions. Predicted increases in atmospheric CO2 concentrations can affect both Si accumulation and endophyte function, but these have not been studied in combination. © 2023 The Authors.