Sistemas de cultivo de grãos no Oeste paranaense e seus impactos na qualidade física e biológica do solo

Abstract

Brazilian agriculture has stood out at a global level due to its great productive potential, so that Brazil has become one of the largest exporters worldwide and identified as the main supplier of food to the world in the coming decades. Having the capacity to grow two or more crops per year in some regions, this intensive production has influenced soil quality. With the aim of evaluating the effects of this influence on the physical and microbiological quality of the soil, the main grain production systems in Western Paraná were adopted. The design adopted was that of cazualized blocks with five treatments and four replications. The treatments were soy/corn 2nd harvest (S1), soy/corn 2nd harvest/black oats after corn harvest, with alternation to wheat (S2), soy/corn 2nd harvest + Brachiaria (S3), soy/wheat (S4) and soy/oats (S5). The experiment was implemented in January 2020 with the corn crop and lasted until the corn harvest in the 2022 harvest. For the soil structural assessment, rapid soil structure diagnosis (DRES) was carried out and the samples were collected at the layer of 0 – 25 cm, for determining the geometric mean diameter (GMD), aggregate stability index (IEA), soil organic carbon (TOC) and for the analysis of microbial biomass carbon, basal respiration, enzyme analysis ß-glycosity, Arylsulfatase and phosphatase were collected samples in the 0 – 10 cm layer. When evaluating the soil structure via DRES, the IQES of managements S1, S2 and S3 presented 4.32, 4.29 and 4.47, respectively, statistically different from managements S4 and S5, which presented an IQES of 3. 51 and 3.54. For the geometric mean diameter (GMD), aggregate stability index (IEA) and soil organic carbon (TOC), the production systems were similar. In the evaluation of the effects of management on the soil microbiota, the parameters of microbial biomass carbon, basal respiration, ß-glucosity, Arylsulfatase and phosphatase, there was no difference between the managements, so it was not possible to highlight the effects resulting from the management employees. The short period of time that elapsed between the implementation of the experiment and the collection of samples had a direct effect on the results, based on the fact that the alteration of these characteristics through cultural management requires more time to be able to measure their effects.