Abstract

ALVES FLORES, Rilner et al. Potassium Nutrition In Ratoon Sugarcane Under A Conservation Cropping System. Cienc. suelo [online]. 2014, vol.32, n.1, pp.53-62. ISSN 1850-2067.

Ratoon sugarcane response to potassium is dependent on the environmental conditions of the region. Cropping systems that do not burn crop biomass after harvest leave crop residues on the soil, affecting the soil-plant nutrient dynamics system and fertilizer requirements. The objective of this study was to evaluate the effect of potassium fertilization of first and second ratoon sugarcane crops on potassium contents in the soil, in the plant, and yield and quality of stalksin an Oxisol under a conservation cropping system. The following potassium rates were tested: 0, 27, 54, 108, and 162 kg K ha^-1, arranged in a randomized block design with five replicates. The application of potassium increased soil nutrient concentrations at six months, reaching 2.87 and 2.61 mmol_c dm^-3 with the highest rate in the first and second ratoons, respectively. The increase in available exchangeable-K content in the soil favored a greater plant uptake of this nutrient, reaching 12.1 and 10.0 g kg^{-1 in the first and second ratoons, respectively. The increase in potassium absorption by plants was reflected in the production of stems; the highest yields (87.0 and 132.9 t ha-1}) were obtained with the application of 162 kg K ha^{-1 in the first and second ratoons, respectively.}

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