Modeling relationship between soil potassium, plant potassium, yield and juice quality of sugarcane

Potassium plays a crucial role in sugarcane growth, yield formation, and sugar accumulation. A field experiment was conducted to model the relationship between soil potassium, plant potassium uptake, yield, and juice quality of sugarcane under different potassium split application schedules. The experiment was carried out for two plant crops and one ratoon crop on black cotton soil at Vasantdada Sugar Institute farm using a randomized block design with three replications. Nine potassium management treatments, including recommended dose of fertilizers, farmers’ practice, and soil test–based fertilizer (STBF) approaches with varied split applications, were evaluated. Pooled results revealed that application of 100% recommended dose of potassium (RDK) based on soil testing, applied in four equal splits at planting, 45, 180, and 240 days after planting, significantly increased cane yield (124.2 t ha⁻¹), commercial cane sugar (CCS) yield (19.6 t ha⁻¹), plant population, cane height, cane girth, and benefit–cost ratio (4.5) compared to RDF. Juice quality parameters such as brix, pol, purity, and CCS percentage were not significantly influenced by potassium split application. The study concluded that soil test–based potassium application in appropriate splits improves productivity and profitability of sugarcane without adversely affecting juice quality.