Application of Glycerin and Polymer Coated Diammonium Phosphate in Alkaline Calcareous Soil for Improving Wheat Growth,Grain Yield and Phosphorus Use Efficiency

Low-use efficiency of phosphatic fertilizers in calcareous soils is a serious issue worldwide resulting in sub-optimal phosphorus (P) availability to plants. Polymer-coated fertilizers provide an effective solution to enhance P-use efficiency in such soils by reducing fixation and ensuring slow and consistent phosphate supply to growing plants. The present field experiment was conducted to evaluate the effectiveness of commercial diammonium phosphate (DAP) fertilizer and coated DAP with polymer and/or glycerin to improve plant growth, grain yield, and P-use efficiency of wheat crops. The results revealed that application of 100% recommended rate of glycerin + polymer coated DAP significantly enhanced plant height, number of fertile tillers m^-2, 1000-grain weight, grain yield, and P uptake in comparison with commercial DAP fertilizer. Moreover, polymer coated DAP produced comparatively better results than glycerin coated DAP alone. The sustainable yield index, P agronomic and recovery efficiencies were also improved and recorded higher with glycerin + polymer-coated DAP fertilizer at 100% of the recommended rate. Furthermore, higher P uptake, P recovery, and agronomic efficiencies in response to coated DAP were found responsible for sustainable wheat yield. Overall, the glycerin + polymer-coated DAP with 75% recommended rate showed statistically identical results to uncoated DAP with 100% recommended rate. The amount of applied P vulnerable to fixation was significantly reduced with the application of glycerin + polymer-coated DAP thereby resulting in improved plant growth, grain yield, and P-use efficiency of wheat crops.