Physical attributes of soil under amazon forest conversion for different crop systems in southern Amazonas, Brazil

The conversion of forested areas into cropping systems modifies the soil physical attributes and affects the environmental and economic sustainability of agricultural activity. Thus, this work aimed to evaluate the modifications caused in the physical attributes of the soil in the area of guarana, cupuacu, and annatto compared with forest area in southern Amazonas. In the areas of forest and guarana meshes of 90 m × 70 m and regular spacing between the sampling points of 10 m × 10 m, in the area of annatto meshes of 90 m × 56 m and spacing of 10 m × 8 m, for cupuacu meshes of 54 m × 42 m, with spacing between the sampling points of 6 m × 6 m. The samples were collected in the depths of 0.00–0.05, 0.05–0.10, and 0.10–0.20 m, with 80 sampling points in each area, making 960 samples in the four areas. The cupuacu area most closely resembled the most diverse aspects of soil physical attributes with the forest area, and this was noticeable through the averaging test along with the principal component analysis, thus indicating that this crop is the least harmful to the studied soil, as well as the adopted systems of cultivation cause modifications mostly superficially, being these modifications little noticeable in layers superior to 10 cm.