Manejo químico e físico do solo em área de pastagem para o cultivo de soja em diferentes sistemas de produção

Abstract

The growing demand for food ally to the country's need to ensure positive results in the trade balance, direct, increasingly, studies to agriculture with high yields. In order to achieve these results with low-impact activities, was aimed with this work, to verify the effect of no tillage with scarifier and the use of fertilizers and corrective performed in the culture of brachiaria preceding soybean cultivation, as a low fertility soil and degraded structure, to improve soy production environment and forage conducted in no tillage system with integrated Crop-Livestock. The experiment was conducted in extensive grazing area at the Experimental Farm of the University of Western São Paulo - UNOESTE in Presidente Bernardes-SP, in a soil classified as Acrisol dystrophic. The treatments consist of plots submitted or not to mechanical handling with scarifier type matabroto, each plot gets five chemical treatments, as follows: 1. Without fertilization and liming (control); 2- Application of lime; 3 Application of lime + gypsum; 4- Application of lime + gypsum + NPK; 5- Application of lime + gypsum + NPK + micronutrients. Both the management with ripper as chemical treatments were made 30 days prior to desiccation of pasture (45 days before soybean sowing) in 2013 and were repeated in the year 2014. The experimental design was in bands, in factorial scheme 2 x 5, with four replications. To evaluate the effect of the treatments was determined straw contribution by brachiaria and soil samples were collected in the layers 0-10, 10-20, 20-40 and 40-60 cm, which were physically analyzed for density soil, porosity, water retention curve in the soil and aggregate stability. The soil was also analyzed for particulate C and N fractions and associated minerals. Soybean yield was determined in the season 2013/2014 and 2014/2015. During the cultivation of soy in the 2014/2015 crop was evaluated soil moisture profile. Data were subjected to analysis of variance and t test comparison of means at 5% error probability. The benefits brought by scarifying the soil physical properties are not lasting, since the chemical quality contributes to the structuring of the soil medium and long term.