Abstract:
Urea consisting 46% Nitrogen (N) by weight is the most common and principal nitrogen rich fertilizer used in today’s world. Almost half of world population use it to increase the productivity of crop. However with low nitrogen use efficiency of urea and severe micronutrient deficiencies like Zinc (Zn), the productivity has not been up to the mark and nutritional quality of foods from these crops is very low. The early decomposition and fast release rate not only leads to decreased nitrogen use efficiency but also leads to contamination of ground water and hazardous emissions to atmosphere. Similarly the micronutrient deficiencies like Zn are transferred from soils to plants and to humans and animals who feed on the foods from these plants. This pose a major threat for agriculture globally and future food security.
For this purpose, seven coated urea fertilizers Zinc oxide-coated (ZnO), Zinc oxide sonicated-coated (ZnO-Son), Zinc oxide with Gelatin-coated (ZnOG), Gelatin-coated (G), Zinc oxide with molasses-coated (ZnOM), Zinc sulphate with molasses-coated (ZnSM) and Zinc sulphate-coated (ZnS) urea were prepared using different coating solutions in a fluidized bed coater. All samples were characterized through SEM to check the surface morphology of coated fertilizer and examined through XRD and FTIR techniques to observe compositions and interactions between urea and coating materials. Crushing Strength tests were carried out to verify if coated samples could withstand the physical impacts of inventory and transportation operations.
Pot tests with Rye grass as test crop were also carried out to evaluate effect of coating on yield, N and Zn uptake. Soil samples were also taken to determine Zinc content in soil for each applied fertilizer sample.
Characterization tests verified the presence of component materials in the coated samples and physical nature of interaction between urea and coated materials. ZnOG was the best sample in terms of yields , N and Zn uptake and Nitrogen use efficiency. All the samples of Zinc oxide resulted in improved response in terms of plant yields, N and Zn uptake.
Keywords: Nitrogen use efficiency, Zinc (Zn), Micronutrient deficiency, Coated urea, Nitrogen and Zinc uptake, Gelatin.
