Milson Serafim

and 6 more

The present study was conducted in areas of large-scale soybean cultivation under long-term no-till (NT). Soil samples from depths of 0.0-0.10 (L1), 0.10-0.20 (L2) and 0.20-0.40 m (L3) were obtained from 65 commercial farms characterized by a high soybean yield in the state of Mato Grosso, Brazil. Oxisols were the predominant soils in these farms, which were located within the Cerrado Biome, and the main textural classes were loamy sand, sandy loam, sandy clay loam, sandy clay and clay. The following physical properties of soil were measured: penetration resistance, bulk density, particle density, total porosity, field moisture capacity, saturation and residual moisture contents, soil water retention curve (SWRC), inflection point, plant available water, n and α parameters of the Van Genuchten equation, S index, and clay and sand contents. In addition, the soil organic matter (SOM) and its densimetric fractions were also determined. The average soybean yield of the studied areas in the last three years was 4.13 Mg ha-1; however, 26 farms had yielded above 4.20 Mg ha-1. Only some of the physical properties at L1 layer, including the penetration resistance, bulk density and the porosity-related parameters, were significantly related with the soybean yield. The SOM and its fractions were directly influenced by the clay or sand contents. In conclusion, the areas with higher productivity under long-term NT showed an adequate S index at three studied layers with values of 0.11, 0.67 and 0.84 at L1, L2 and L3 layers, respectively.