Improvement of Nitrogen Use Efficiency Derived from Ammonium Sulfate Substitute Fertilizer in Sugarcane Cultivation through the Addition of Organic Amendment

Abstract

For increasing nutrient use efficiency and cane yield on application of ammonium sulfate (AS) fertilizer substitution was performed through addition of soil amendment. A pot experiment was conducted for seven month of sugarcane growth. The experiment used factorial randomized complete block design with three replication. Factor I was the application of AS fertilizer and its substitution which consisted of nine levels: three treatments using AS fertilizer, three treatments of AS substitute fertilizers using the mixture of urea+gypsum and three treatments using the mixture of urea+gypsum+biocompost. Factor II was the kinds of soil amendment which consisted of three levels: calcite, boiler ash, and biochar of sugarcane trash and one control treatment. The measured variables were leaf N content and uptake, nutrient use efficiency, and yield variables. The results of this study showed that the treatment using mixture of urea+gypsum tend a higher N uptake than AS fertilizer. Application of boiler ash and biochar had the highest N nutrient upatake. The highest nutrient use efficiency was found at the lowest rate of mixture of urea+gypsum (100 kg N ha-1) with application of soil amendment using biochar or boiler ash. The average increase in cane yield on this treatment compared to control by 250%. It is suggested that application of organic soil amendment is needed to increase N use efficiency of AS substitute fertilizer.