RESPOSTA DA CANA-DE-AÇÚCAR A ADUBAÇÃO POTÁSSICA NOS TABULEIROS COSTEIROS DA PARAÍBA

Abstract

New measures for management of sugarcane (Saccharum spp.), in particular the harvest without straw removal by burning, has led producers to review their fertilization practices. In the state of Paraiba, that culture plays an important role in the economy as well as great importance in its PIB, but in the state, that culture is produced mostly in coastal soils (soils of tableland) with low natural fertility and easy leaching of potassium element (K). This study aimed to evaluate the response of cane sugar submitted to different concentrations of K (Potassium) and application forms (cover and gutter). The experiments were conducted on the farms of the mill: Japungu and Monte Alegre. Nitrogen and phosphate fertilizer was the same (20 kg ha-1) in all experimental areas. The experimental design was randomized blocks factorial (2 x 5) + 1, with four replications, the first factor corresponding forms of fertilizer application (single dose at planting, and split rates at 60 and 120 days); The second factor the doses of K (0, 60, 120, 180 and 240 kg ha-1); and a control (formulation used by the mill). The plots consisted of ten lines of 10 m area being useful the 6 central and line spacing according to each mill. After harvesting and subsequent weighing, samples from each plot for industrial analyzes were withdrawn: Weight of Wet Cake (PBU); Total soluble solids (BRIX); Sucrose (POL); Purity of the juice cane sugar (PZA); Industrial Fiber Cana (FIB); Percentage Gross Sugar (PCC); and total recoverable sugar (ATR). After the joint analysis of data, it was observed that the Mill Monte Alegre with full irrigation system showed the best results for industrial variables as well as higher productivity in all treatments with average productivity of 120.12 t ha-1 compared to 60.1 t ha-1to the mill Japungu under rainfed system. In relation to the adopted fertilization management (foundation and cover), no differences were seen in the average for the variables analyzed within production units.