Fontes de fósforo associadas á adubação orgânica no plantio da cana-de-açúcar

Abstract

The objective of this work was to evaluate different sources of phosphorus fertilization in association with organic matter in sugarcane crop. The experiment was conducted in Penápolis, northwest region of the Sao Paulo state, Penapolis during 2006/2007 agricultural year with RB 72454 genotype. Six treatments were done with phosphorus sources for the crop in soluble, reactive and natural form being this last source supplied in three doses associated with organic matter. The phosphate fertilization was applied in the ridge during the sowing. Crop was conducted following the rules for the region. The complete randomized blocks design was used with four repetitions. The following characteristic were studied: sugarcane tillering was at 90 days, growth and absorption of phosphorus by the plant at 180 days, soil soluble phosphorus at 360 days and yield at twelve months old crop. Results indicated that there was no influence of phosphate fertilization in crop tillering, whereas the treatment that received fertilization with reactive phosphate increased the number of internodes in the plant at 180 days. Treatments that had received fertilization with soluble phosphate and natural phosphate in 200 dose kg per hectare provided significant increments in foliar P concentration at 180 days. Concentration of phosphorus in soil was increased with fertilization using reactive e natural phosphate in association with organic matter. The results of productivity of the culture showed that the use of different sources of phosphorus in the culture did not modify significantly the production of the year sugarcane