In no-tillage systems, plant residues are used as soil cover to control soil erosion and promote nutrient cycling. The objective of this study was to evaluate the dry matter production and nutrient accumulation after different crop sequences in no-tillage. A field experiment was carried out on a Rhodic Eutrudox in Jaboticabal, SP, Brazil (48°18'W and 21°15'S). A randomized split-block design with three replications was used. The treatments were combinations of three summer crop sequences (soybean-corn rotation, corn monoculture and soybean monoculture ) with seven crops in the second growing season (maize, grain sorghum, sunflower, sunn hemp, pigeon pea, oilseed radish, and pearl millet). The experiment started in 2002 and in this study, the dry matter production and nutrient accumulation by crops were evaluated in the growing seasons 2007/2008 and 2008/2009. The grain crops in the second growing season (maize, sorghum and sunflower) produced residues with lower nutrient amounts and less dry matter than the off- season crops that were cut at full flowering (sunn hemp, pigeon pea, oilseed radish, and pearl millet). Pearl millet and sunn hemp produced most dry matter and highest nutrient accumulation. Pearl millet showed highest K and Mg accumulation and sunn hemp highest N and P accumulation. A better development of the grasses was observed in the second growing season when planted after summer soybean, resulting in higher dry matter production of pearl millet and higher grain yield of maize and grain sorghum.
biomass; macronutrients; winter crops
