Desempenho agronômico de sucessões de culturas em plantio direto e convencional no semiárido mineiro

Abstract

In order to evaluate the agronomic performance and the efficiency of the water use by systems of succession of conventional tillage (CT) and no- tillage (NT), two experiments were carried out in the North of Minas Gerais. Experiment 1 consisted of planting in succession of grain corn / common bean, and experiment 2 consisted of planting in succession of sorghum / green corn. The treatments were arranged in a 2x2 factorial scheme, being two management systems (CT and NT) and two years of cultivation, with ten repetitions in tracks. Yield and some production components of each crop, besides water use by the crops in the winter, in each succession system were evaluated. The data were submitted to analysis of variance, and in the case of significance, the means were studied by the F test at a significance level of 1 and 5%. It was concluded that NT provides a greater mass of one hundred grains, yield of ear without husk and increase of productivity in 21.45% in grain corn. There is no difference between management systems for the final stand and bean grain yield; however, no-tillage increases the efficiency of water use by common bean by 66.86%. The NT provides higher plant height and increases yield of green and dry matter by 39.65 and 84.26%, respectively, in the sorghum crop. In green corn cultivation the NT provides larger length of ear, larger number of commercial ears, higher percentage of commercial ears, and an increase of 11.99 and 21.80%, respectively, in the yield of total and commercial ears without husk. The NT also increases the efficiency of water use by corn-green in 84.16%.