Relative Significance of N Nutrition on Biomass, Yield and Economics of Sugarcane (Saccharum Officinarum) Plant – Ratoon System

Field experiments were conducted at Sugarcane Breeding Institute, Coimbatore during two crop seasons as plant and ratoon crop to find out the effect of levels of N nutrition on the biomass and yeild of sugarcane. Treatments involving four nitrogen levels viz., 280, 350, 420 and 490 kg N ha-1 were laid in the main plots while the subplot treatments included its split application at different days after planting (DAP) (3 splits on 45, 90, 135 DAP, 4 splits on 45, 90, 135 & 180 DAP, 5 splits on 45, 90, 135, 180 & 225 DAP, 6 splits on 45, 90, 135, 180, 225 & 270 DAP). The treatments had a significant influence on the number of millable canes recorded in both the plant and the ratoon crop. Biomass yields that were highest was obtained with 350 kg N/ha. High yields of 140.7 tha-1 and 118.6 tha-1 were recorded with the application of recommended dose of nitrogen (280 kg N ha-1) in the plant and ratoon crop respectively. Yields with N application at 45, 90 and 135 DAP exceeded those recorded over other splits. The economics recorded also favoured the above treatment