Fitossociologia De Plantas Daninhas De Pastagens Cultivadas Sob Dois Níveis De Degradação Em Cerrado, No Mato Grosso Do Sul

Abstract

Cerrado (Brazilian savanna) is the second biome in Brazil, 2 million km 2 , approximately 22% of the country (Eiten 2001), covering nearly the whole central-West region. Soils are generally dystrophic, but well structured, often on flat or gently rolled relief, what favors cattle ranching and mechanized crops (Pivello 2006). cattle farming has expanded considerably in the region, after the 1970s, due to low prices of land, finance, and forage ABSTRACT RESUMOspecies well adapted to climate and soils (Perón & Evangelista 2004).Sown pastures, in general, present high initial productivity, however, within a few years, go through a decline process (Dutra et al. 2004). Excessive stocking rate, wrong choice of forage species, and inadequate management have caused an increasing process of pastures degradation (Santos & costa 2002, Perón & Evangelista 2004, Dias Filho 2007, which reaches 80% in the central-West Brazilian region (Perón & Evangelista 2004). According to 1. Trabalho recebido em abr./2009 e aceito para publicação em set./2010 (n° registro: PAT 6051/