Disponibilidade de água em solos de Alegrete sob diferentes usos e manejos

Abstract

More and more agriculture is expanding its production areas, so it invests in constant innovative management practices to facilitate cultivation and increase production. However this abrasive exploration causes damage to the soil structure when poorly managed. To begin planning good conservation practices it is necessary to analyze the soil as to its physical and chemical structure in order to be able to adopt appropriate methods. Water is one of the main sources that the soil must provide the plants, and according to its structure it facilitated or prevented its availability. Aiming at these parameters, the objective of this work is to analyze the physical attributes of the soil in different uses and management in the city of Alegrete - RS. The field samples were collected from six types of soil management operated in the municipality, in two layers of soil, the first 0-10 cm and the second 10-20 cm, soil moisture was considered to perform the texture calculations, it was also soil density, particle density and soil porosity were evaluated. In relation to the soil moisture content, this is linked to the residual organic matter of the crops, which acts as a soil protector and decreases the direct insertion of the solar radiation and consequently the evaporation of the water present in the soil. The density of particles is tied to the soil texture. Clay soils have greater retention capacity and water availability for plants. Most of the analyzed soils indicate that the management is not being adequate to maintain a productive soil, because the density was in the limit predetermined as critical and with restrictions in the volume of pores. Soil compaction is one of the factors that diminishes the productivity of crops and consequently the profit of the producer. The no-tillage system improves soil structural conditions, with higher porosity and lower soil density.