Hydro-physical properties of soil and pasture vegetation coverage under animal trampling

Propriedades físico-hídricas do solo e cobertura vegetal de pastagens sob pisoteio animal

ABSTRACT

Soil compaction and pasture degradation are often due to the pressure exerted by the animals’ hooves. In this sense, this study aimed to verify possible changes in the soil and changes in the pasture vegetation coverage due to animal trampling. Thus, a study was carried out on a farm in the ‘Agreste’ region of Pernambuco, Brazil. Soil samples were collected before and after the grazing period, with 36 points regularly distributed in an area of 40 × 40 m managed under continuous grazing, with a stocking rate of 12 AU ha^-1. At each point, density, total porosity, humidity, and penetration resistance of the soil at a depth of 0-0.10 m, as well as hydraulic conductivity and organic matter in the soil surface, were determined. Before and after grazing, images from the Sentinel-2A satellite were also obtained to observe the response pattern of pasture vegetation over time using the Normalized Difference Vegetation Index (NDVI) and Pasture Vegetation Coverage (PVC). The physical-hydric attributes of the soil were subjected to factor analysis. NDVI and PVC maps were evaluated for spatial variability. After the grazing period, there was a change in the attributes of the soil under study due to the animal trampling. Remote sensing (NDVI and PVC) highlighted patterns of variation, such as the reduction of pasture and possible areas of preference for the animals.

Key words: factorial analysis; soil compaction; remote sensing