Fosfatos reativo e solúvel associado a torta de filtro na adubação da cana planta

Abstract

The use of reactive rock phosphates, with gradual and continuous availability of phosphorus in the soil solution may be an alternative to ensure the productivity of the plant and ratoon cane and reduce the formation of labile P not. A blend of phosphate fertilizers with different solubilities may be a strategy to provide readily available P in order to plant sugarcane productivity and to provide P that will be available over the years, because only the use of soluble phosphates in planting sugarcane can unavailable phosphorus the development, maturation of sugarcane plant and ratoon due to fixation by soil. Furthermore, there may be the effect of changes mineral source of P due to the presence of organic fertilizers. Thus, the present work was to study the best ratio in the production of phosphate fertilizers plant cane, and determining the effect of the filter cake mixed with these sources of minerals P, Super Single (SS) and the Natural Phosphate Arad (FNA), and evaluate biometric parameters, technological and production of cane sugar. The experiment was conducted at the Campus II of the University of the West Paulista - UNOESTE in Presidente Prudente-SP, in a soil classified as Typic dystroferric between March 2011 and June 2012. The experiment was conducted in randomized complete block design with four replications in a split plot, as the plots formed by the application of 150 kg ha-1 P2O5 via superphosphate (SS) and (or) phosphate Arad reactive (FNA). And the subplots were composed by the presence or absence of filter cake (TF). Thus, treatments were: 1) 100% SS with TF; 2) 100% SS without TF; 3) 66% 33% SS and ANF, with TF, 4) 66% 33% SS and ANF, without TF; 5) 33% SS and 66% FNA, with TF; 6) 33% SS and 66% FNA without TF; 7) 100% FNA, with TF; 8) 100% FNA without TF, all applied in the furrow planting. The results were submitted to analysis of variance and t test comparison of means at 5% probability. The total or partial replacement of the soluble source of phosphorus by a source less reactive did not alter the productivity of the sugar cane plant, regardless of the presence or absence of filter cake. Fertilization at planting with 66% of the dose and the remainder with Super Simple Natural Phosphate Arad increased levels of available P in soil. No effect of phosphorus sources and filter cake on technological parameters of sugar cane cut first. The use of filter cake did not increase the productivity of the sugar cane plant, independent of the phosphorus source used.