Fontes de fósforo (fluida ou sólida) na produtividade agrícola e industrial da cana-de-açúcar

Abstract

With the increased use of liquid fertilizers in sugarcane farming, having deeper knowledge about agronomic effects of some of the fertilizer products becomes a necessity. The study was carried out under field conditions using the cultivar SP71-1406. The experiment was driven during approximately three years, and was located at São Luiz SA sugar-mill, Pirassununga (SP). The objective of this study was to evaluate the agronomic effect of different phosphate fertilizers on plant cane using liquid and solid forms. Residual effect, sugarcane yield and quality of the raw material were some of the factors studied. The phosphorus sources tested were triple superphosphate, single superphosphate, phosphoric acid and a mixture of phosphoric acid + rock phosphate. They were used in the rates of 100 kg ha-1 of P2O5. The first two fertilizers (superphosphates) were applied in the granulated form and the last ones in the liquid form. The phosphorus fertilizers were applied on the furrow just before planting. The results allowed concluding that there was no difference between solid and liquid form in the agricultural and industrial productivity. After the third cut, the Agronomic Efficiency Index showed that phosphates source reduced in the following order: single superphosphate (110%) > triple superphosphate (100%) > phosphoric acid (73%) > phosphoric acid + rock phosphate (48%).