Biomass Accumulation and Technical and Economic Efficiency of Potassium Sources Applied via Fertigation to Corn

To achieve high corn yield, optimal amounts of nutrients that can be extracted by the crop must be supplied at adequate proportions. Vinasse from sugarcane ethanol production can be applied as a soil fertilizer to corn crops in ethanol production plants. In this context, the present study compared the effects of mineral potassium fertilization with potassium chloride and organic fertilization with concentrated sugarcane vinasse on corn dry matter and grain yield and explored the technical and economic efficiency of these sources. The experiment was carried out at the experimental station of the Federal Institute Goiano, Rio Verde Campus, Brazil. The experiment followed a randomized block design in a 2 × 4 factorial scheme, with three replicates. The treatments comprised two sources of potassium, namely concentrated vinasse and potassium chloride, applied at four doses of potassium, representing 0%, 50%, 100%, and 200% of the recommended rate for corn. The dry matter accumulation of corn throughout the crop cycle, yield components at harvest, and technical and economic efficiency of the applied potassium sources were measured. Neither potassium dose nor its source affected leaf, stem, and aboveground dry matter accumulation at harvest. Regardless of the potassium source, the 100% dose produced higher cob dry mass, grain dry mass, grain dry mass per ear, grain yield, number of bags of 60 kg ha−1 produced per hectare, and harvest index. The agronomic efficiency of vinasse compared to potassium chloride was 68.5% at the 100% dose of the recommendation, showing enough potential as an organic fertilizer in corn crop.