Development of novel slow release urea fertilizer

Abstract

The earth’s population is increasing every day which cause a rise in global food requirements. To overcome the problem of global food security, farmers are bound to employ the chemical fertilizers for agricultural needs as well as to minimize the environmental pollution hazard in the form of various emissions to atmosphere. The most important nitrogenous fertilizer that is extensively used in crop growing is urea that contains about 46% of nitrogen content. Nevertheless, it was found that up to 70 percent of the nitrogen is lost to atmosphere during common urea application that resulted in significant economic loss, contamination of atmosphere and enhanced expenditure. The efficiency of urea utilization can be enhanced by reducing its dissolution rate. This research will focus on the use of biodegradable organic polymer with bentonite, gypsum and sulphur as a coating material. Coating technique will be used to produce slow release urea fertilizer. Slow release urea samples were prepared by using rotary drum coating technique. Various formulations of different coating materials were made and their dissolution rates were determined. Spectrophotometry and High pressure liquid chromatography (HPLC) were used to calculate the dissolution rates of slow release urea fertilizers. Surface morphology was determined by using Scanning Electron Microscopy (SEM). Optimization study carried out on best selected sulfur and gypsum coated urea samples: S.G urea, 4S.G urea, 6S.G urea and 8S.G urea. Dustiness of these samples was calculated. Higher efficiencies were observed with increasing amount of binder. Effect of binder directly related to the efficiency and reduction in dissolution rate. These materials not only increased the efficiency of fertilizer in terms of reduction in dissolution rate of urea fertilizer but also acted as multi functional fertilizers or compound fertilizers.