Growth and yield of sugarcane as influenced by nitrogen levels and green manuring

Dhaincha (Sesbania aculeata) was sown, as an intercrop (one and two rows) between two rows of sugarcane, 30 days after spring planted sugarcane and green manured (in situ) at 45 and 60 days after sowing (DAS). Variations in shoot and root biomass (kg/ha), fresh weight of root nodules (kg/ha) and nitrogen accumulation (kg/ha) in dhaincha were observed. The highest shoot and root biomass and nitrogen accumulation was observed at 60 DAS with 2 rows of dhaincha. Nitrogen application to plant crop of sugarcane produced higher shoot biomass of dhaincha at 225 kg N/ha. Plant crop yield in sugarcane was significantly reduced when two rows of dhaincha intercrop were incorporated (green matured, in situ) at 60 DAS. This was largely due to reduction in biomass and leaf area. Ratoon yield, on the other hand, was significantly increased (5–8%) with dhaincha green manuring in plant crop. Highest ratoon yield was observed with 2 rows of dhaincha intercrop incorporated at 60 DAS. The present study highlights that integrated nutrient management in sugarcane can be practiced by green manuring with dhaincha intercrop and fertilizer N application for sustaining the yield of sugarcane-ratoon system.