Atributos bioquímicos em um plintossolo háplico sob uma cronossequencia de uso agrícola

Abstract

The biochemical attributes participate in key processes such as the terrestrial ecosystem degradation and cycling of organic matter and energy flow for several trophic levels. These indicators can be used for monitoring anthropogenic interference, because they are very sensitive to changes, especially in sensitive ecosystems such as presented in Haplic Plinthosol. In these soils occur the fields de murundus that are elevations formed by actions termitaria that vary in diameter and height in relation to the field grassy floodable. They have great importance for the conservation of watersheds in the region, however these areas were subjected to human action and the construction of drains become farmland, so the aim of this study was to evaluate the impact of agriculture on a chronosequence of agricultural use of a Haplic Plinthosol through biochemical indicators such as soil microbial biomass (C, N), soil microbial respiration, enzyme activity (urease, phosphatase and Hydrolysis of fluorescein diacetate) and metabolic quotient. The study consisted of four areas of fields with mounds three areas that are subject to no-till fields and an area of mounds without human influence. The results were submitted to ANOVA and Tukey mean test using a 5% significance level (SAEG). As a complementary analysis technique was used by multivariate canonical analysis involving all biochemical variables the results can be seen that for some variables there were improvements in soil quality. However, even after 16 years of conservation system there was no recovery compared under reference (Coval), in the variables of nitrogen in microbial biomass, on organic carbon, acid phosphatase, and urease. The adoption of no-tillage with soybeans (crop) and maize (second season) for this soil should be amended and consider input from other cultures and especially some with the purpose of introduction of nitrogen by legumes.