Spatial variability of soil physical-hydric attributes under bovine trampling in agreste of Pernambuco State, Brazil

Abstract

Soils under pastures suffer physical modifications, in greater or lesser intensity, via the action of animal trampling. Thus, the aim was to evaluate the spatial dependence of soil physical attributes under bovine trampling. The trial was performed at Roçadinho Farm, Agreste of Pernambuco, Brazil, in a 40 x 40 m paddock that was managed with continuous stocking by bovines and 12 AU ha-1 stocking rate. Soil samples were collected before and after grazing using a 6 x 6 m grid, totaling 36 sampling points. At each point, the bulk density, total porosity, moisture, soil penetration resistance at 0.00-0.10, 0.10-0.20, and 0.20-0.30 m depth were estimated, as was the hydraulic conductivity on the saturated soil surface. Descriptive statistics and geostatistics supported the data analysis. A normal distribution was verified for all variables, which were scored as either low or high variability in terms of the variation coefficient. The physical attributes (density, total porosity, moisture, soil penetration resistance and hydraulic conductivity) of the soil sampled presented a strong spatial dependence before and after grazing.

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

“…The results of the factor analysis and remote sensing obtained are confirmed by Batista et al (2019) in a study of the spatial variability of the soil physical attributes, in the same area of the present research. The authors observed that after 21 days of grazing, the physical attributes of the analyzed soil were altered by the action of animal trampling, mainly in the eastern region of the paddock, where according to the NDVI maps ( Figures 3A and B), this region had the highest values (0.27 -0.30) for the period before grazing and the vegetation in this area was highly reduced (0.12 -0.15), which may indicate a preferred grazing area.…”