Influence of slope segments on soil physical attributes in two toposequences in areas of highland swamp, Areia, PB

Abstract

With the intensification of human activities as a result of the global demand for inputs from agricultural production, natural resources have been suffering serious impacts, mainly reflecting the degradation of primary vegetation cover. Thus, many studies have sought to evaluate these impacts on the physical attributes of the soil. Therefore, the objective of this work was to evaluate the influence of slope segments on soil physical attributes in two toposequences in highland swamp areas, Areia, PB. Two toposequences were selected under forest fragment and pasture, establishing a path from the “spike” towards the smoothest slope of the relief, these segments were determined based on the “break” of slope of the terrain. Mini trenches were opened in the 0.00-0.20 m layer, samples were collected in the different slope segments: top, mid-slope and deposition foothills. Then, 30 volumetric rings of 5.0 cm in height and 5.0 cm in internal diameter were collected and 30 samples preserved in the form of a clod. Texture analysis, soil density, macro, micro, total porosity, aggregates, hydraulic conductivity and gravimetric moisture were performed. Descriptive statistical analyzes and analysis of variance were performed, being compared by the Tukey test at the 5% probability level. There was a predominance of sand fraction contents in all slope segments studied, with a slight increase in clay contents in the pasture area in relation to the forest area, a fact probably associated with the material of gneiss origin and not the pedoforms. The physical-hydric attributes showed similar results with few exceptions.