Erodibilidade do solo em áreas sob diferentes usos no Assentamento São Francisco na região de Canutama-Am

Abstract

Erodibility is the soil property that represents the greater or lesser susceptibility with which its particles from the most superficial layer are detached and transported to lower locations by erosive agents, which can cause environmental and economic problems. This study aimed to evaluate the spatial variability of soil erodibility in areas under different uses in the São Francisco settlement in Canutama, AM. The collections were carried out in forest areas, and in Guaraná (Paullinia cupana), Urucum (Bixa orellana) and Cupuaçu (Theobroma grandiflorum) crops. For each area, grids were established according to the dimensions of the crop. In the guarana and forest areas, 90 x 70 m meshes were established with regular spacing of 10 x 10 m between sampling points, in the annatto area the established mesh was 90 x 56 m with spacing between sampling points of 10 x 8 m, for the cupuaçu area, the mesh had dimensions of 54 x 42 m, with regular spacing between sampling points of 6 x 6 m. Making a total of 80 samples in each area, totaling 320 samples in the four evaluated areas, each point being georeferenced with GPF. Then, samples with preserved structure were collected, in the 0.00-0.20 m layer, for the determination of physical properties and for the realization of organic matter. At the end of this step, indirect models for predicting soil loss were used, where the erodibility factors (K, Ki, Kr and Tc) were estimated, and finally descriptive statistical and geostatistical analyzes were performed to model the spatial variability of the attributes studied. The evaluated attributes showed spatial dependence, varying between strong and moderate, being these adequate to the spherical model, characterized as the one that best adapts to the soil attributes and explained the spatial variability of these variables. For the application of the WEPP erosion prediction model, the value of the erodibility factor of the study areas the areas that presented the lowest (Ki) were guarana and annatto with 4.70 x10-2 ha-1 MJ-1 mm-1 ha