Atributos químicos de solo cultivado com diferentes culturas de cobertura

Abstract

The effect of cover crops annually implanted in the summer, since 2001, under no-tillage system, on the soil chemical attributes was evaluated. The experiment was carried out in Embrapa Rice & Beans, in Santo Antônio de Goiás, GO, Brazil, in a Dystrophic Red Latosol (Red Oxisol). Brachiaria brizantha, corn (Zea mays L.) associated with B. brizantha, pigeon pea, millet, Panicum maximum, sorghum, Stylosanthes guianensis, and sunn hemp were used as cover crops. Sixty days after the cut of the cover crops, common bean crop was implanted, under a central pivot sprinkler irrigation system. In November 2001, 2005, and 2006, soil samples were collected in the depths of 0-5 cm, 5-10 cm, and 10-20 cm. Immediately after the 2005 sampling, it was applied 4,000 kg ha-1 of dolomitic lime, in all the experimental area. Cover crops affected soil pH and magnesium content in the superficial layer. Soil under millet showed higher phosphorus content in subsuperficial layers, in relation to the initial values. The soil P and Cu contents were higher in the subsuperficial layers, while the other chemical attributes were higher in the superficial layer. There was movement of Ca and Mg in the soil profile, one year after the application of lime in the soil surface.