Desenvolvimento do DRIS para a cultura do amendoim

Abstract

The Diagnosis and Recommendation Integrated System (DRIS) is presented as a mathematical method that defines the critical linkages and expresses the recommended nutritional values for a culture, thus this tool can solve nutrition problems in plants. The aim of this study was to elaborate the DRIS norms for the cultivar Runner IAC-886 (Arachis hypogaea L.) in the region of Guararapes-SP / Brazil. The data for this work were obtained in area of sugarcane renovation. Samplings were covered by 112 plots with different productivities and the chemical leaf analysis (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn). The reference population (A) was determined through the cut-off point with yields of up to 20% of maximum yield (≥ 4,367 and ≤ 5,458 kg / hectare), and the remaining defined as subpopulation (B) (≥ 2,519 and ≤ 4,367 kg / hectare). The relationships between nutrients in the direct and inverse order (X / Y and Y / X) were calculated. After that, the means (XA and XB), the standard deviations (DP A and DP B), the variances (S2A and S2B) and their relationships (VA / VB) were calculated, resulting in 110 nutritional relationships, and keeping the 55 (direct or reverse). The indices of each nutrient were determined, where (+) excess, (-) limiting and (0) balanced. The Nutrition Balance Index was calculated, and the best (21.8) belongs to productivity of 3,697 kg / ha. Critical ranges and nutritional values were defined for each nutrient evaluated. In conclusion, the best IBN (21.8) was of the productivity of 3,697 kg / ha, the most limiting nutrient in the study was K and the most excessive S.