Cycling of N and P in Grass-Alone (\u3ci\u3eBrachiaria\u3c/i\u3e) and Mixed Grass/Legume (\u3ci\u3eBrachiaria/ Desmodium ovalifolium\u3c/i\u3e) Grazed Pastures in the Atlantic Forest Region of Brazil
There are estimated to be \u3e 80 M ha of Brachiaria pastures in the tropical regions of Brazil. When continuously grazed with only modest fertiliser inputs (and no N) these pastures can maintain reasonable cattle weight gains (\u3e 200 kg LWG/ha per year). However, without fertiliser and when overgrazed, LWGs fall rapidly to low levels. Recent studies have shown that N and P deficiency are the most important factors limiting productivity. The objective of this study was to study fluxes of N and P in the pasture system in order to understand resilience to poor management and minimum nutrient requirements to guarantee their sustainability