Grazing Effect on Soil Properties in Dry Subtropic Steppes of Azerbaijan

Resumo

The article presents changes in the morphological and diagnostic parameters of gray-brown soils of dry steppes under the effect of grazing on a reserve and with regulated and free grazing. It has been revealed that, in comparison with the reserve regime, long-term intensive free grazing on gray-brown soils of dry steppes resulted in a 50–55% decrease in the projective vegetation cover, a poorer (loose) soil structure, compaction, and a 9.45% decrease in humus content and a 6.07% decrease in organic carbon content in the top horizon. The thickness of the humus horizon decreased by about 50%. There was a twofold decrease in the nitrogen content, while the drop in available phosphorus and potassium compounds was relatively smaller. The physical and mechanical soil properties also worsened: soil compactness in the 0–10-cm layer dropped by 0.13%, valuable clay particles were washed from the topsoil, the soil structure became more powdery, and the content of valuable water-stable aggregates and their water resistance decreased. The goal of the study is to develop more efficient pasture use for grazing in dry steppes.