Effect of Phosphate Fertilization on Flooding Pampa Grasslands (Argentina)

摘要: Abstract We postulate that phosphorus (P) fertilization may increase above-ground net primary productivity ( ANPP ) of rotationally grazed rangelands without reducing the legume component, as does N fertilization. In doing so, we evaluated effect phosphate on production and relative contribution legumes grasses native old tall fescue Festuca arundinacea Schreb) grasslands; recorded annual production, seasonal productivity, biomass each component. The experiment was conducted in a commercial farm located Flooding Pampa managed under rotational grazing. Treatments consisted two programs (66 (P 66 29 kg P · ha -1 supplied rock and/or monoammonium from 1997 to 1999) nonfertilized control. A paddock dominated by grassland another were selected. Nine 5-ha plots established paddock, treatments randomly assigned. During experimental period, October 1998 1999, total harvested plot before after grazing period separated into components: fescue, other C 3 perennial grasses, legumes, 4 forbs, standing dead material. component estimated during warm (October 1998–February cool (March 1999–September season. grassland, increased both seasons; therefore 40% higher than doubled plots. Phosphate didn't but it did seasons.