Sistemas de manejos e seus efeitos nas propriedades físico-hídricas do solo e na produtividade de milho e soja

Abstract

This study has the objective to understand the effects of different types of soil management systems in the physical-hydric proprieties of the soil as in the productivity of the crops. The experiment was made in a experimental area of Federal Institute Farroupilha, Alegrete campus, Rio Grande do Sul. The soil of the experimental area is classified as a dystrophic red argisol. In order to evaluate the changes of physical e hydric proprieties, undisturbed samples were collected as well as infiltration tests and penetration resistance of the soil in the field, and hydraulic conductivity under constant stress in laboratory. These evaluations occurred soon after the intervention of management and sowing, and subsequently after each end of the summer cultivation cycle. For yield evaluation, samples were collected from a predefined area. Results of the first sample (after soil management intervention) show a change in macro porosity values (Ma) only in the 0-5 cm soil layer, where SPD treatment turned out to have lower Ma values compared to other managements of the same soil layer. The increase of Ma for ESC and PC management is related to mechanical soil mobilization. For the values obtained after the corn harvest (2015/2016), there are no significant differences for the physical or hydric properties evaluated. However, after soybean crop cultivation (2016/2017), there is an increase in the scarified system Mi, in relation to other soil management systems. The adoption of scarification systems at a given time should be well evaluated given the real benefits this operation can bring to the implemented cropping system.