Ammonia Volatilization Loss From Subsurface-Applied Urea.

Urea fertilizer represents over 50% of nitrogen fertilizer market worldwide. Urea is a good nitrogen source mainly because it has high nitrogen analysis (46%), it is easy to handle, it is easy to store, and present little transportation restrictions. However, losses related to ammonia volatilization make this important nitrogen source a challenge to be managed mainly when urea is surface-applied and not incorporated into the soil. Best management practices recommend incorporation of surface-applied urea with rainfall, irrigation, or tillage to eliminate volatilization losses. This practice can greatly increase the efficiency of urea. However, some studies have indicated that volatilization loss from urea is still present even after incorporation under certain conditions. The objective of this report was to revise some of these studies looking at conditions when incorporated urea is still prone to volatilization loss and strategies to minimize it.