RESISTÊNCIA À PENETRAÇÃO EM LATOSSOLO AMARELO SOB DIFERENTES CONDIÇÕES DE USO

Abstract

To evaluate the physical attributes and mechanical resistance of the soil to penetration in areas with different conditions of use in a Yellow Red Latosol located in the city of Areia, PB, as well as the effect of the use and cultivation system on a compaction and physical . The work carried out in the Laboratory of Soil Physics of the Department of Soils and Rural Engineering, Center of Agrarian Sciences of the Federal University of Paraíba– DSER/CCA/UFPB. The perimeter of the chosen areas was obtained by means of a portable GPS survey. A rectangular mesh in the 10 x 10 m spacing was used for sampling, and the points located at the intersections of the meshes were georeferenced, where deformed samples were collected for physical determinations in the layers of 0-10 cm and 10-20 cm deep. Three areas with different conditions of use were also selected: I. Area cultivated with corn; II. Native forest area and III. Pasture area, and in each area was selected a plot of 60x60 m, within these were collected 20 points in each area. The variables analyzed were soil penetration resistance, soil gravimetric moisture, dispersed clay, flocculation degree, particle density and total soil porosity. Isoline maps were made by kriging method. The design was completely randomized (DIC), and the data were submitted to analysis of variance and Tukey test (p <0.05). As the depth increased, soil density increased, mechanical resistance to penetration increased, and total porosity decreased in area I and II, except for pasture. The corn cultivation system favored the formation of a more compacted subsurface layer than the superficial layer. While in the pasture area it was the opposite way, favoring the obtaining of soil physical conditions more favorable as to the mechanical resistance of the soil to the penetration along the profile. Pasture cultivation favored soil physical conditions more favorably when compared to the conventional system, the latter needing more care to preserve favorable conditions for agricultural development.