Variabilidade espacial de atributos químicos e físicos do solo e da produtividade de culturas utilizando ferramentas da agricultura de precisão

Abstract

Knowing the spatial variability of chemical and physical properties of the soil can be a great tool to aid in the management of crop agronomic importance such as soybeans and corn. The objective of this study was to evaluate the variability of chemical and physical properties of soil for understanding the spatial and temporal variability of the soybean crop yield in the crop 2014/2015 and the corn in the crop 2014/1025 and 2015/2016. The study was conducted in commercial farming and succession of soybean and corn, seeded in 0.45 m spacing under Oxisol, in a plot of 49,12 ha, in Dourados-MS. The data were collected at 53 points separated by 100 m apart. The composite samples were formed by eight (8) sub-samples randomly taken around each sample point, in the layers 0,0-0,10 m e 0,10-0,20 m, for the evaluation of soil chemical properties and granulometry. The sampling related to soil resistance to penetration study was performed with electronic penetrometer in 47 points to a depth of 0.40 m. According to the generated maps there is a low need for liming (NC) in the study area, because the maps related to chemical attributes met indices considered high for Ca, Mg, P and K. It was observed that the area presents compression ratio in most of the area 2 to 4 MPa, which shows that there is no need for a sub soiling. Through the maps of productivity were verified points of the area with high and low productivity, and their textural characteristics in both layers. Finally, analyzing the main components of chemical and physical properties of the soil is an effective strategy to explain the spatial and temporal variability of grain crops productivity.