The knowledge of variability of plant nutrition and grain productivity in cultivated areas may provide important information for rational use of fertilizers and soil amendments. The objective of this case study was to determine the corn plant mineral nutrition variability through the fractionation of a commercial grown corn field into small management cells. The study was carried out at the farm Alto Alegre in Planaltina, Goiás State, Brazil, on a Typic Dystrarox soil in 373 ha area of corn crop during the crop year of 2003/2004. After outlining a polygon of area it was divided into 80 management cells of 4 ha each. The leaf sampling followed a diagonal with twelve points to constitute a representative composite sample within each cell. The leaf samples were analyzed for macro and micronutrients. Yield for each cell was obtained through grain yield monitor of a combine harvester equipped with GPS. For data variability analysis descriptive statistic parameters were considered. Test for correlation coefficients were accomplished considering the significance level of 5%. The variability of nutrient content in the diagnostic leaves were considered low for N, P, K, S and Mg content; and medium for Ca, Cu, Fe, Mn e Zn. Yield variability showed yield differences among cells. Linear correlation coefficients between nutrient content and grain yield were significant and negative for Cu, Mn and Zn.
Zea mays; mineral nutrition; field-scale; no-till; Oxisol; Cerrado
