Evaluation of Sheep Trampling at Different Grazing Periods on Soil Attributes

Abstract

With the objective of evaluating the possible deterioration in some physical and chemical soil attributes, caused by sheep trampling in pasture areas compared to preserved areas. The study was conducted at the Instituto Federal de Educação, Ciência e Tecnologia da Paraíba - Campus Sousa, located in the Irrigated Perimeter of São Gonçalo, between the geographic coordinates 06o 50` 22 "S; 38o 17 ` 42" W; at 220 meters of altitude. The statistical design was in Randomized Blocks (DBC), with 3 treatments composed of: T1= no animals (preserved); T2= rainy period sheep grazing; T3= dry period sheep grazing, with six repetitions each. To determine the chemical attributes, soil samples were collected at a depth of 0 - 20 cm to determine (pH, phosphorus, potassium, sodium, calcium, magnesium, aluminum and organic matter) and physical attributes (sand, silt clay, soil density, total porosity, water dispersed clay) except for bulk density was taken from unformed samples at a depth of 0 - 10 cm from the soil. The sheep grazing in the different periods promoted soil compaction expressed by increased soil density, reduced total porosity and lower clay aggregate content. The permanence of grazing animals promoted a reduction in soil chemical quality, notably for phosphorus, calcium, magnesium and SOM contents in grazed sheep during the dry season and an increase in sodium and PST, compared to the area without grazing (preserved).