Variabilidade na distribuição de resíduo da soja durante a colheita e seu efeito sobre a produção de matéria seca do nabo forrageiro em sucessão

Abstract

Soy is an oilseed that contains a high protein and oil content in its grains. Because it is rich in protein in grains, Nitrogen (N) as a constituent of this molecule is demanded in large quantities for the development of the crop, but it also demands significant amounts of other nutrients, such as Ca2+ and Mg 2+ , which have specific functions within the crop. plant. A high content of these nutrients remains in the dry matter and is available for cycling and use by the successor crop. Therefore, an adequate regulation of the spreading mechanism of the harvester is necessary, avoiding the uneven distribution of waste, and consequently the heterogeneity of the disposal of these nutrients to the soil. Aiming this, the work aims to evaluate the variability in the distribution of soybean harvest residues and its influence on the production of vegetable biomass from forage turnip, subsequent culture, through the absence of adequate regulation of the chopper / spreader mechanism of the harvester, and consequently, an irregular horizontal distribution of soy residues. The study was conducted in the agricultural year 2019/2020, in the municipality of Cândido Godói / RS, and consists of 4 treatments: T1: arranged in the central axis of the cutting platform; T2: arranged between the central cutting axis and the right end of the platform; T3: arranged in the range between two passes of the cutting platform; T4: arranged between the central cutting axis and the left end of the platform; with 10 repetitions. The distribution of dry mass of soybean culture after harvest and fresh mass of forage turnip was evaluated, determining the distribution of accumulation of N, Ca and Mg according to the existing literature. With the results it was observed that, in the absence of an adequate regulation of the spreading mechanism of the harvesting machine, the residual of the soybean culture remains in greater accumulation in the central range of harvesting operation, and consequently, a variation in the nutrient disposition in the mass drought, which fluctuated between 72 kg ha-1 of N, 88.3 kg ha 1 of Ca, and 45.1 kg ha-1 of Mg in the range of greatest deposition of residues, to 18.8 kg ha-1 of N, 23.0 ha-1 of Ca, and 11.8 Kg ha-1 of Mg in the range of lowest deposition of soy residues. The variation in the distribution of soybean residues influenced the production of vegetable biomass from the forage turnip crop in succession, correlating positively with the addition of soy straw.