INTER-RELAÇÕES SOLO, PLANTA E ANIMAL EM SISTEMAS DE INTEGRAÇÃO AGRICULTURA-PECUÁRIA

Abstract

The agriculture-livestock integration system (IAP) is a strategy that involves the intercropping and succession of annual crops, pastures and animals in the same area, attenuating the soil erosion process and promoting carbon sequestration, considered environmental services. In this scenario, the objective was to evaluate the performance of beef cattle under grazing in Tamani grass (Panicum maximum cv. BRS Tamani) and Paiaguás grass (Brachiaria brizantha cv. BRS Paiaguás) in integrated systems in the second harvest as well as the effects of animal trampling during grazing and the traffic of agricultural machinery under soil compaction, during the transition from livestock to agriculture phase and determine the efficiency of top-dressed biomass formation for no-tillage soybean, in relation to the traditional agricultural system of succession soybean-corn. The experiment was carried out at the Instituto de Ciência e Tecnologia Comigo (ITC) in the municipality of Rio Verde-GO, Brazil. For livestock phase, forage was sown on February 28, 2018, remaining in free growth for 84 days after sowing, then Nelore cattle were inserted in each grazing module, evaluated in four grazing cycles. After removing animals from the area, soil samples with preserved structure were collected, at depths of 0-0.05; 0.05-0.10; 0.10-0.20; 0.20-0.30; 0.30-0.40 and 0.40-0.50 m in the row and inter-row positions of the crop for soil physical-hydric determinations, in two seasons, after soybean sowing and before harvest. The experimental design was a randomized block with eight replications and a 2 x 4 + 1 factorial scheme, with soybean cultivation in succession under biomass of paiaguás and tamani grass, and four resting intensities, 54, 47, 40 and 22 days after the animals exit to form biomass for planting soybeans in the next harvest, and one additional treatment of soybeans sown under top-dressed corn biomass grown in a traditional no-tillage system, considered as a control. It was possible to verify that the forages were able to supply the nutritional need of the animals and that even in a period of low precipitation, the paiaguás grass promoted greater meat production and high formation of top-dressed biomass. It is worth mentioning that tamani grass obtained the greatest increase in biomass after desiccation. Forages in the regrowth intensities did not affect the performance of soybean sowing in succession. The systems in the integration showed higher values of soil density in relation to the succession corn-soybean in the layers of 0.05 to 0.10 m, however, this increase did not reduce the soybean grain yield. Cultivation systems did not influence soybean productivity.