Atributos químicos do solo em áreas manejadas com agricultura de precisão no norte do Rio Grande do Sul

Abstract

Precision farming (PF) tools are essential for managing soil fertility as well as for managing the means of production. From this point of view, this study starts from the premise that the use of PA tools, besides providing the correction of soil chemical attributes, favors the decrease of spatial variability of soil chemical attributes, making it possible to understand and interpret the behavior of spatial and vertical variability of soil chemical attributes in farming areas in the northern region of the State of Rio Grande do Sul. This study was conducted in 13 agricultural areas located in the northern region of the State of Rio Grande do Sul, covering an area of 1211.05 ha. The soil samples were performed with the aid of a auger attached to a quadricycle, at two depths, the first from 0 to 0.15 m and 0.15 m to 0.30 m. The data were submitted to exploratory analysis using descriptive statistics and the study of spatial variability with the aid of geostatistics. The pH and base saturation values (V %) are low, while the calcium and magnesium contents are high at both sampling depths, for all areas studied. For discussion, the data were in three groups, the first being the attributes of acidity and related bases, the second the levels of phosphorus (P), potassium (K), sulfur (S) and organic matter (MO) and the third the micronutrients, boron (B), manganese (Mn), zinc (Zn) and copper (Cu). The spatial variability was considered low to moderate for the values of pH and magnesium (Mg) contents and high for the contents of V % and calcium (Ca). At a depth of 0 to 0.15 m, the contents were medium for MO and high for P, K and S, and at a depth of 0.15 to 0.30 m were high for K and S, medium for P and low for MO. The values of coefficient of variation (CV), were classified in low, medium and high, being that, the spatial dependence was identified only for the contents of P and MO. The Zn, Cu, B and Mn contents are high in all areas at the two sample depths. The CV was classified as high for all micronutrients evaluated, as well as at the two sampled depths, and for Cu and B some areas had their CV classified as moderate.