Spatial relationship between the stock of nutrients and density of a soil cultivated with coffee plants

Abstract

The study of the soil fertility spatial variation has grown in importance, in discussions on agricultural management, once the uniform approach of cultivated areas provides inconsistent results, capable of affecting the crops yield. By using multivariate geostatistics methods, this study aimed at evaluating the spatial relationship between the stock of nutrients and density of a humic Rhodic Hapludox. The study was conducted in an area cultivated with Coffea arabica L. (Catucaí cultivar), in a sample grid with 100 points. The soil sampling was performed in the 0-0.20 m layer, in order to determine the soil density and the P, K, Ca and Mg contents, which were converted into stock values. After this transformation, the data were analyzed by using descriptive and exploratory statistics, determining the correlation between density and stocks. Then, the univariate and multivariate geostatistics were used, followed by interpolation with ordinary kriging and cokriging. The distribution of nutrients stocks was inversely proportional to the soil density, except for the P stock. The cokriging allowed to characterize the soil, favoring the interpretation of the fertility spatial distribution behavior.