Atributos físicos do solo e produtividade da soja em função de diferentes rotações de culturas

Abstract

Soybean production is crucial for agribusiness in the world and Brazil. Thus, crop management strategies have been sought to increase their yield and provide the conservation of soil quality for agricultural production. This work's objective was to evaluate the effect of different soil coverings on soybean performance and soil physical attributes. A randomized block design with 13 treatments and four replications was used. The treatments constituted production systems, involving species of oilseeds and grasses as crops predecessor to soybeans. Rotations with oilseed crops (canola, safflower, crambe, niger), grains (wheat, oats, corn+vetch, corn+brachiaria), green manures (crotalaria, vetch, and turnip), and single brachiaria occurred in the autumn-winter of each agricultural harvest, and in the summer the crop rotation was done with soybean. Cover plant dry mass, soil organic matter, physical soil attributes, and soybean production components were evaluated. The brachiaria, safflower, and niger coverings provided greater organic matter in the soil at a depth of 0.10 to 0.20 m when produced in the 2016/17 agricultural harvest. The macroporosity, microporosity, total porosity, and soil density in the two depths studied were not altered by the cultivation of the different coverings, while the cultivation of crotalaria, brachiaria, and canola provided the lowest values of soil resistance to penetration at a depth of 0.00 to 0.10 m. The analysis of the main components of the soil's physical attributes and organic matter demonstrates an efficient strategy to explain the variability of the effects of cover crops in rotation with the soybean. Plant height, the height of first pod insertion, and soybean yield are influenced by the management of rotating cover crops, while the number of pods and knots per plant remains unchanged.