Fertilidade do solo após terminação intensiva de bovinos a pasto

Abstract

Brazilian beef cattle breeding stands out worldwide for good results. However, the criticisms are really focused on the activity of large pasture areas, with low stocking rates per hectare. Thus, one of the intensified forms of meat production is the intensive termination of cattle to pasture (TIP), in addition to producing a high rate of supplementation. By ingesting the food sources provided in the DIP, the animals use a fraction for the production of meat and the remainder is excreted via faeces and urine, and the material is left on the soil, thus becoming a source of nutrients, along with cover. Therefore, the objective of this research was to measure soil fertility changes, C and N stocks, and the spatial distribution of its attributes after 102 days under TIP. The experiment was carried out at Embrapa Agrossilvipastoril, in the municipality of Sinop, in the state of Mato Grosso. An area of 7.5 ha was divided into four peaks of the same size, and then a random sample mesh with 100 georeferenced points was inserted. At each point of the sample mesh, a sample of deformed soil was collected in the layers of 0.00-0.10 and 0.10-0.20m, followed by 40 male Nelore, uncastrated, divided in 4 lots of 10 animals each, were inserted in the area. The fields remain in the field for 102 days, receiving 2% of body weight (CP) in supplement. After the period of permanence of the animals, the soil samples were again collected in the morphs and sampling points at the beginning of the experiment. In addition, independent soil samples were collected in the 0.00-0.10 and 0.10-0.20m layers, at the sampling points, to determine carbon (EC) and nitrogen (EN) stocks. The dose of supplemental paste compounds increased potassium (K), calcium (Ca) and magnesium (Mg) to the soil equivalent to 164 kg ha-1 of K 2 O, 94.2 kg ha -1 of Ca, and 40 1 kg ha-1 of Mg. The EC was altered only in the 0.10-0.20 m layer, with an increase of 4.34 Mg ha-1. Moreover, the increase was 170 and 310 kg ha-1 in the layers of 0.00-0.10 and 0.10-0.20 m. The permanence of the animals in the area altered the spatial distribution of the soil in the layers of 0.00-0.10 and 0.10-0.20 m. The animal component under TIP associated with a vegetation cover was necessary to increase the fertility of the soil, altering in a significant way the spatial distribution of its attributes.