Influence of compost/sludge application on sugarcane yield and nitrogen requirement on a sand soil

Mineral soils in southern Florida are very low in organic matter content and most of the nitrogen (N) for sugarcane (Saccharum spp.) must be supplied in split fertilizer applications. Information is needed regarding how the interaction of organic amendments and fertilizer N influences sugarcane yields. A field study on a sand soil (Alfisol) was established to determine (1) potential sugarcane yield benefits of a compost/sludge amendment, and (2) the influence of the amendment on N fertilizer requirement. A split-plot Latin square design was used with five N rates (main plots) and presence or absence of compost/sludge broadcast at 113 m(3) ha(-1) (subplots). Annual N rates were 0, 67, 134, 202, and 269kg N ha(-1). Compost/sludge application increased cumulative t sucrose ha(-1) by 36% averaged across N rates. The amendment also lowered annual N requirement by an average of 38%, but maintenance applications of compost/sludge will be required every four years.