A review on management of urea fertilizer to minimize losses of nitrogen from rice fields
Namrata Kashyap, Biplab Choudhari and Budhesh Pratap Singh
Volatilization of NH3 from urea and other N fertilizers is controlled by a number of diverse soil properties and environmental conditions that make losses diﬃcult to predict in the ﬁeld. In general, higher pH, temperature, crop residue, and moisture conditions increase the potential for volatilization, while increased incorporation depth from tillage, rain, or irrigation decrease volatilization potential. Due to soil characteristics such as high Cation Exchange Capacity and buﬀering capacity, substantial inputs of bicarbonates and Ca on irrigated land, and generally cool conditions during major fertilizer application periods, the potential for substantial urea volatilization in many cropping systems of the is likely relatively low. Nevertheless, the lack of direct ﬁeld measurements of NH3 volatilization is coupled with the complexity of fertilizer management practices for the many diverse crops grown in the area is reason to exercise caution and use good urea management practices. Understanding the factors that inﬂuence volatilization will allow urea users to select management practices that minimize volatilization.