Biomass yield, nutritional status and industrial quality of sugarcane as a function of nitrogen and potassium fertilization

Abstract

Sugarcane plant uptakes a large amount of nutrients from the soil. Thus, crop yield may decrease due to the reduced availability of nutrients in the soil. The aim of this study was to evaluate plant nutritional status, yield and juice quality of variety RB867515 in the first regrowth cycle, fertilized with doses of nitrogen and potassium. Therefore, a study was set up in a randomized complete block design (RCBD) with four replicates. The following treatments were applied to the first regrowth sugarcane: (T1) control: no nitrogen (N) and potassium (K) fertilization; (T2) N and K fertilization, replenishing 75% of the N and K removed by cane-plant harvest; (T3) N and K fertilization, replenishing 100% of the N and K removed by the cane-plant harvest; (T4) N and K fertilization, replenishing 125% of the N and K removed by the cane-plant harvest. The increase in the fertilizer dose promoted a linear effect in leaf N content and biomass of N and K concentration, but did not influence the quality of the juice, which had average concentrations of 22.23; 19.63; 88.30 and 16.50 (Brix, Pol, Purity and PC, respectively). TRS was also not influenced by fertilization, with an average value of 162.82 kg t-1. Biomass yield increased linearly with fertilization, yielding the regression equation of Y = 82.74 + 0.3394 x, with R2 of 0.9824. The values obtained indicated excellent quality sugarcane.