Improved management increases carrying capacity of Brazilian pastures

Abstract

Grazing pasture without appropriate soil conservation and animal management often leads to reduced soil quality and decreased productivity because of trampling induced compaction. Our objective was to evaluate the effect of three conservation-based pasture management strategies on soil physical attributes. The treatments were (1) Brachiaria decumbens + mineral-N fertilization, (2) mixed pasture + legume (forage peanut, Arachis pintoi), and (3) Brachiaria without fertilization were compared with a native grassland reference area without management. The hypothesis is that nitrogen fertilization favors an increase in the animal stocking rate, maintaining the physical quality of the soil. The treatments had no significant effect on soil porosity, bulk density, or water retention. The S-index showed that intense animal trampling in the treatment with nitrogen fertilization resulted in the most intense degradation. Mixed pasture with the intercropped legume and N-fertilization maintained soil physical quality similar to the area without management, reinforcing the importance of appropriate soil management practices in pasture. However, although the N-fertilized area had soil physical quality similar to the others, it could support more animals, suggesting an economic advantage over other soil management practices. To preserve or enhance soil physical quality, mixed pastures and fertilization can be adopted, increasing the soil load-bearing capacity, which represents more animals per area.