-The objective of this work was to evaluate the effect of winter land use on the amount of residual straw, the physical soil properties and grain yields of maize, common bean and soybean summer crops cultivated in succession. The experiment was carried out in the North Plateau of Santa Catarina state, Brazil, from May 2006 to April 2010. Five strategies of land use in winter were evaluated: intercropping with black oat + ryegrass + vetch, without grazing and nitrogen (N) fertilization (intercropping cover); the same intercropping, with grazing and 100 kg ha -1 of N per year topdressing (pasture with N); the same intercropping, with grazing and without nitrogen fertilization (pasture without N); oilseed radish, without grazing and nitrogen fertilization (oilseed radish); and natural vegetation, without grazing and nitrogen fertilization (fallow). Intercropping cover produces a greater amount of biomass in the system and, consequently, a greater accumulation of total and particulate organic carbon on the surface soil layer. However, land use in winter does not significantly affect soil physical properties related to soil compaction, nor the grain yield of maize, soybean and common bean cultivated in succession.Index terms: compaction, cover crops, crop-livestock integration, no-tillage, organic carbon. Pastagem e coberturas de inverno e seus efeitos sobre o solo e culturas estivaisResumo -O objetivo deste trabalho foi avaliar o efeito de usos da terra no inverno na quantidade de palha remanescente, nas características físicas do solo e na produção de grãos das culturas estivais de milho, feijão e soja, cultivadas em sucessão. O experimento foi conduzido na região Planalto Norte de Santa Catarina, de maio de 2006 a abril de 2010. Foram avaliados cinco usos da terra no inverno: consórcio de aveia-preta + azevém + ervilhaca, sem pastejo e sem adubação nitrogenada (consórcio cobertura); o mesmo consórcio, com pastejo e 100 kg ha -1 de nitrogênio (N) por ano em cobertura (pastagem com N); o mesmo consórcio, com pastejo e sem adubação nitrogenada (pastagem sem N); nabo forrageiro, sem pastejo e sem adubação nitrogenada (nabo forrageiro); e vegetação natural, sem pastejo e sem adubação nitrogenada (pousio). O consórcio cobertura proporciona maior quantidade de biomassa para o sistema e, consequentemente, maior acúmulo de carbono orgânico total e particulado na camada superficial do solo. No entanto, as formas de uso da terra no inverno não alteram significativamente as características do solo relacionadas à compactação, nem a produtividade de grãos das culturas de milho, feijão e soja, cultivadas em sucessão.Termos para indexação: compactação, plantas de cobertura, integração lavoura-pecuária, plantio direto, carbono orgânico.

The integrated crop-livestock system is a key strategy for both grain and livestock production. The cultivation of grass species in between two soybean cropping seasons has been an important component of this system, in Brazil. Thus, this study aimed to evaluate the yield of glyphosate-resistant soybean cultivars intercropped with Urochloa species, under different forage management systems. A total of six experiments, consisting of three soybean cultivars (BRS 295 RR, BRS 316 RR, and BRS 294 RR) and two grass species (Urochloa ruziziensis and Urochloa brizantha), were established. For each experiment, four treatments (soybean only; grass only; soybean intercropped with a grass species, with the application of glyphosate to decrease the growth of grass; and soybean intercropped with a grass species, without growth suppression) were evaluated in a completely randomized experimental design, with four replications. For each experiment, only one soybean cultivar and one grass species were used. The grasses were sown in the soybean inter-rows at 27 days after sowing (DAS), while the glyphosate application to the treatment with grass suppression was performed at 84 DAS for the soybean or 57 DAS for the grasses. The yields of the three soybean cultivars were not significantly affected by either grass species, even though the shoot dry-matter yields for both of the intercropped grass species were high, though lower than the values obtained without the interference imposed by soybean.