Abstract:
Zinc is an essential component for the healthy growth of plants and animals. Zinc concentration level in different arable soils of the world is very low. Owing to continuous crop production, the amount of Zinc is decreasing day by day in arable soils. Urea is the major macronutrient fertilizer used for the healthy growth of plants. Combining urea with zinc can give a perfect solution, to increase zinc coated fertilizer use. The focus of this research was on synthesizing and characterization of zinc coated Urea fertilizer. Zinc Oxide particles were coated on Urea granules by different techniques i.e. wet coating and slurry coating. Different binders were being used for coating purpose. The coated urea granules were investigated through different analytical techniques like SEM, XRD and XRF to know the morphology, structure of coating and composition respectively. In both coating techniques, Slurry coating technique was best because in this technique all coated particles of zinc oxide were of uniform size and coating efficiency was very high as compare to wet coating technique. In wet coating, coated zinc oxide particles were of not same size, large lumps and irregularities were seen on the surface of granules in SEM images, amount of zinc coated was low. In all the binders, Slurry used in Zinc Coated Urea 7 containing molasses, paraffin oil and water mixed with zinc oxide was the best of all. By using this binder slurry, the coating efficiency of zinc was very high. The release rate of zinc from all coated granules was measured up to 24 hours. Among all, release rate of zinc in Zinc Coated Urea 7 (ZnU7) was the steadiest, while using other binders or slurries zinc release rate was either so fast or so slow. The amount of dust produced in zinc coated urea 7 was comparatively lowest of all samples. Over all, it was observed that coating of zinc oxide by slurry containing molasses, paraffin oil and water was the best in term of coating efficiency, uniformity in size of coating particles of zinc oxide, morphology and release rate of zinc oxide.
