Optimization of nitrogen and phosphorus fertigation schedule for drip-irrigated sugarcane

Abstract:

Sugarcane is one of the most nutrient-demanding crops grown in tropical India, yet conventional broadcast fertilisation wastes up to 40% of applied nitrogen through volatilisation and leaching. This research tested eight drip-fertigation schedules combining varied nitrogen (150, 200, 250 kg N/ha) and phosphorus (40, 60, 80 kg P₂O₅/ha) splits across three growth phases of sugarcane variety CoP 09437 at Central Agricultural University, Imphal, Manipur, during 2022-2023. The highest cane yield (108.4 t/ha) was obtained with 200 kg N + 60 kg P₂O₅ distributed as 25%-40%-25%-10% across germination, tillering, grand growth, and maturity phases. This treatment also recorded the best nitrogen use efficiency (54.2 kg cane/kg N) and phosphorus recovery of 23.8%. Juice quality parameters including Brix, pol, and purity showed no significant variation across fertigation schedules. The optimised split schedule reduced total fertiliser input by 18% compared with the blanket recommendation while maintaining equivalent yield, making it both cost-effective and environmentally sound for drip-irrigated sugarcane in northeast India.