Culturas de cobertura na qualidade química do solo em consórcios de segunda safra

Abstract

The inadequate soil management in grain production areas within the Cerrado-Amazon ecotone has been increasingly leading to soil degradation. A promising solution to maintain the sustainability of agricultural systems is the inclusion of cover crops in a crop rotation plan. Thus, the objective of this study was to evaluate the effects of intercropped cover crop species, with or without second-season corn, on dry matter production and nutrient cycling. The study was conducted in Sorriso city, Mato Grosso state, at coordinates 12°37'57.2''S and 55°58'86.3''W. The data from the experiment correspond to the first year of study. The experiment was set up in a completely randomized design in strip plots with seven treatments and five replications. The tested treatments included corn + Urochloa ruziziensis, corn + U. ruziziensis + Crotalaria spectabilis, Sorghum BRS Ponta Negra + C. spectabilis, Grain Sorghum BRS 373 + Stylozanthes BRS Bela, U. ruziziensis + C. spectabilis, and the sextuple treatment (U. ruziziensis + Sesame BRS Anahí, C. spectabilis + Niger + Forage Turnip + Buckwheat). The sole corn treatment was used as a comparison parameter. pH in water, calcium (Ca), magnesium (Mg), potassium (K), phosphorus (P), aluminum (Al), sulfur (S), organic matter (OM), potential acidity (H+Al), effective cation exchange capacity (t), cation exchange capacity at pH 7.0 (T), base saturation (V%), and aluminum saturation (m%) were determined. The results showed that the cover crops had significant effects on nutrient cycling in the system, with significant differences in K, S, OM, T, t, and Al levels among the treatments. Intercropping with cover crops resulted in greater increases in potassium and organic matter in the soil.