Effect of phosphorus and potassium doses and their application schedule on yield, juice quality and nutrient use efficiency of sugarcane-ratoon crop sequence

A field experiment was conducted during 2000–2002 to study the effect of P₂O₅: K₂O doses on the productivity; uptake and efficiency of planted crop of sugarcane and subsequent ratoon on silty clay loam soil at Pantnagar. The plant crop responded significantly to application of P and K up to 60 and 40 kg ha⁻¹. When both plant and ratoon crops were fertilized with 60:40 kg of P: K ha⁻¹, these gave mean cane yield of 88.0 t ha⁻¹, sugar yield of 10.6 t ha⁻¹ and net return of Rs. 90643 ha⁻¹, which was higher by 21.5 t ha⁻¹, 3.2 t ha⁻¹ and Rs. 33919, respectively, over no phosphorus:potassium application. The increase in yields and returns was primarily due to production of more number of millable canes with more cane weight. Nutrient use efficiency was also highest with 60:40 kg of P₂O₅: K₂O ha⁻¹ applied to both the crops, being 239 kg kg⁻¹ of P₂O₅ and 359 kg kg⁻¹ of K₂O applied.