Estimation of macroporosity and microporosity as a function of management systems and cover crops in red soils cultivated with soybean

Abstract

Cropping systems are management practices that aim to improve agricultural production. Therefore, conventional cultivation is characterized by using traditional soil preparation techniques, such as plowing and harrowing, and no-till farming, in which there is minimal disturbance, with the soil always covered by cultural remains. The quantification of macroporosity and microporosity is extremely important for determining the physical quality of the soil, however, it is a very laborious evaluation. In this context, the objective of the present work was to estimate these physical attributes of a clay Red Latosol from equations proposed in the literature, as a function of different management systems and preharvest crops in soybean production, based on independent variables such as soil texture and density. The experiment was conducted in a randomized block design with 2x6 factorial scheme and four repetitions, by combining two management systems (no-till and conventional tillage) and five cover crops (crotalaria, cowpea, oilseed radish, millet and lab-lab) and a fallow. The data were submitted to variance analysis and the means were compared using Tukey's test, at 5% significance level. It was concluded that in the 0-0.10 m layer the tillage systems did not present significant differences for the physical attributes evaluated. However, in the layer 0.10-0.20 m the management system under no-till farming showed lower values of soil density and higher macroporosity in comparison to conventional planting. Among the cover crops, the oilseed radish was highlighted in terms of total porosity and soil micrososity, in both layer. Therefore, the determination of the physical attributes of the soil is of great importance for the knowledge of the soil and application of adequate management practices.