Sugarcane Farmers

Six different field experiments were conducted in 2003 to test the effects of fertilizer inputs on the yield and yield components of current sugarcane varieties. Results of a multi-location outfield test to determine the optimum rate of N fertilizer for LCP 85-384 indicated the optimum rate was on the low end of present recommendations. Results of ratoon crop response to N application rates were similar to those of previous years in this large outfield study. Cane yield optimized between 80 and 100 lb N/acre on light soils and 100 to 120 lb N/acre on heavy soils. Sugar yields were optimized at slightly lower rates. Overall, the data indicate optimal response occurs for the variety LCP85-384 at rates 20 to 40 lb N/acre less than now recommended. Nitrogen fertilizer rates from 60 to 180 lb N/ac had minimal effect on cane or sugar yield of first ratoon crops for three varieties. Nitrogen use efficiency for biomass declined with increasing N rate, but tended to be higher across rates for LCP85-384 than the other varieties. Applying a range of N fertilizer rates in early April vs late May for 3rd ratoon LCP85-384 harvested in late September resulted in a slight N rate x timing interaction for cane yield. When applied in April, cane yield from 40 lb N/ac application was less than 80 lbs and above. There were no significant differences among N application rates applied in May. Sugar yield and CRS were unaffected. Broadcasting full or split applications of stabilized ure