Molasses Distillery Slops Supply Nitrogen and Potassium Fertilizer to Flooded Rice

Abstract

Yields of four consecutive rice crops that received P fertilizer only increased with each increment of rum distillery slops, from an average of 2,033 kg of rough rice/ha when no slops were applied to 5,905 kg/ha when 240 hl of slops were applied/ha weekly for 12 weeks starting 2 weeks after planting. At this level of slops, a total of 215 kg of N and 475 kg of K were applied to each rice crop. Applying fertilizer N in addition to 160 hl of slops/ha weekly did not increase yields. Leaf contents of N, P, K, Ca, and Mg were not affected by the level of slops applied. Soil pH decreased with increasing levels of distillery slops. Exchangeable NH₃ content of the soil was not affected by the application of slops. Exchangeable and HN0₃-extractable K increased with increasing levels of slops, from a total of 313 kg/ha when no slops were applied to 699 kg/ha when 240 hl of slops were applied/ha weekly for 12 weeks to four successive rice crops.