Estabelecimento de padrões nutricionais para o ATR da cana-de-açúcar

Abstract

The present research aims to stablish DRIS guidelines for sugarcane plantation based on Total Recoverable Sugars (ATR), through the study of the relation between nutrients and quality as well as their interactions that influence ATR production at sugarcane plantation, like some of the variable able to affect them. Were used foliar analysis results for the nutrients N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn with the productivity of 80 stands which belonged to Maracaí database, an area in the São Paulo State countryside, comprising a total area of approximately 1.020 hectares. These stands presented 4 different genetic materials, RB 72454, RB 845210, SP 813250 and RB 935744. The foliar samples were collected in the months of April to June 2012.It was used, for the formation of the database, the division in 7 ATR productive levels ≥150, ≥152.5, ≥155, ≥157.5, ≥160, ≥162.5, ≥165 Kg.ton-1, for high productivity, with the establishment of all the binary relations among the nutrients studied, then it was averaged the rate, the standard deviation and the variation of each nutrient concentration, as well as the relation among them, in each sub-population, being kept 55 relations that presented the biggest ratio in the variation among the sub-population. It was calculated the index for each nutrient and each population IBN. So, it was defined the productivity of 160 Kg.ton-1 as an index to be used because it has been the one which has presented the best relationship between IBN and the analyzed productivities. It was verified that, among all the analyzed samples, the scarcest were Ca, S, B and Cu. Referring to the nutrients P, K, Fe, Mn, the levels haven’t been different to the existing standards, however, with regard to the others, it was observed in this study, that they have been below existing standards.