Relações de atributos químicos do solo e a produtividade das culturas de soja e milho

Abstract

With the advance the adoption of precision agriculture in Brazil, growing use the technological tools georeferenced soil sampling and crop yield. Relations and crossing data information between these two tools can assist in improving the management of crops through specific recommendations of each element with reduced costs, efficient use of inputs, increasing productivity and profitability of crops. The objective of this study was to evaluate the influence of soil chemical properties on grain yield of soybean and corn in two experimental fields southern Brazil through principal component analysis and hierarchical cluster. The research happened in two experimental areas of 132 and 124 hectares in typical Oxisol. The soil samples were taken with a grid sampling of one hectare in the 0-0.10 m layer. The yields of the cultures were related at the same point each soil analysis using the annual average productivity at a radius of 25 m around each sampling point. At the first experimental area of 132 hectares, were investigated yield maps soybean harvest crop 2008/09; soybean crop 2009/10; soybean crop 2010/11 and corn crop 2011/12. In the second study area of 124 hectares, were investigated yield maps soybean harvest crop 2009/10, corn harvest 2010/11 and soybean crop 2011/12. The selection of yield maps followed the criterion to evaluate crops with less than two years of the completion of soil sampling, where only occurred fertilization of crop maintenance. Both areas had high fertility, the first area to saturation (V) average 65.16% and 83.03% in the second area. At the first experimental area the increase in productivity is being explained by the increase of the attributes: saturation of calcium and magnesium in the cation exchange capacity (Sat Ca, Mg Sat), V, and the calcium: magnesium (Ca: Mg). In the second experimental area the increase attribute chemical Sat Mg committed crop yields. In both experiments the elevation of attributes Sat Ca, V and Ca: Mg contributed to raising crop yields. The balance of cations in the exchange complex was the chemical attributes that best explained the variability in crop investigated.