Parâmetros microbiológicos em sistema de integração lavoura pecuária em função de adubação nitrogenada e pressão de pastejo

Abstract

The crop livestock integration works by diversifying productive methods, making them more sustainable and economically profitable. To that end, it works to improve the soil fertility properties, especially in the biological field, since the living fraction of the soil governs numerous important biological processes for maintenance and functionality of the soil.But one can not work the system in isolation, since it is governed by several factors, such as fertilization and the amount of animals grazing over the area.In this context, the objective of this work was to analyze the influence of nitrogen fertilization time and grazing pressure on the microbiological parameters of the bean crop and on an oat pasture.Soil samples were taken in the agricultural year of 2016/2017, after bean cultivation and the animals’ exit from the oat pasture, in an experiment that was conducted in a typical dystrophic Bruno Latossolo in Abelardo Luz - SC. The experimental design was a randomized complete block design with three replicates (2x2x2).The factors consisted of two levels of nitrogen fertilization times (N-Fert grains and N-Fert pasture), pasture heights (high and low height) and depth of soil collection (0-5 cm and 5-10 cm).It was found that the N-Fert treatment. Grain along with the High Pasture Height is responsible for increasing soil microbial biomass in depth (5-10 cm). It was not observed in the bean culture, a significant influence on the microbiological parameters of the soil, only in the flow analysis of CO2 carried out 24-day after the incubation in the treatment Nitrogenated Fertilization Time at different collection depths and in the parameter qCO2 of the soil, where the difference was between the different pasture heights at different collection depths. Already in the pasture, it was verified that the treatment N-Fert. Grain along with the High Pasture Height is responsible for increasing soil microbial biomass in depth (5-10 cm), however, when handling with N-Fert. Pasture maintaining high Pasture Height, have greater flow of CO2 in the soil, as well as smaller qCO2 in the superficial layer of the soil (0-5 cm), confirming the stability that this management brings to the soil, however it should be emphasized that the winter of 2017 was a meteorologically atypical year, with strong frosts that certainly influenced the result of the work. It is concluded that the microbiological parameters are influenced by the nitrogen fertilization season, as well as by the management of different pasture height and collection depth.