Variabilidade e correlação espacial de atributos químicos do solo na produtividade da soja para agricultura de precisão.

Abstract

The adequacy of the use of agricultural inputs inside of the real needs of each soil and each culture type are fundamental for the sustainability of the agriculture, so much in the economical as in the environmental level. So that this happens is important to know the spatial and temporal variability of the soil attributes, in their chemical characteristics, to map them and to correlate them with the yield, avoiding the unnecessary application of nutrients, what avoids the saturation of the planting areas and unnecessary expenses, also contributing to the reduction of the environmental impacts. In this work the data of the years of 1998 and 1999 of an experimental area (1,74 ha), subdivided in 256 plots, were analyzed. That area belongs to the COODETEC Company located in Cascavel-PR, Brazil. The objective was to carry, through geostatistics methods, spatial analyses of the soybean yield with the soil main chemical attributes (P+, K+, organic matter, pH, S, and soil base saturation). As results, it was obtained the culture yield maps and the soil chemical conditions maps. The maps of the soil chemical conditions were spatially correlated with the soybean yield, as resulted the verification of how much the deficiency or not of determined levels of soil chemical attributes can affect in low or high culture yield. Some attributes did not show significant correlation and others presented weak correlation with the yield, probably because the soil presented good fertility. Thus, in function of this, the located management of the application of the nutrients will be able to contribute in the direction of better distributing fertilizers in the field, placing the necessary one in each part of the area studied.