Ammonia volatilization from ammonium sulfate as sulfur source

Surface application of ammonium sulfate (AMS) as S source to soils with pH >= 7.0 is subjected to ammonia (NH3) volatilization. However, AMS volatilizes less NH3 than urea does. In soils with pH <7.0, unlike urea, very little NH3 volatilization from AMS occurs. The associated N with AMS may enhance early biological N fixation by leguminous crops as compared to S sources without N such as polyhalite.

Automated summary

Surface application of ammonium sulfate (AMS) as S source can lead to NH3 volatilization in soils with pH >= 7.0, but with less extent compared to urea. However, in soils with pH < 7.0, AMS volatilizes very little NH3, unlike urea. The N associated with AMS can enhance early biological N fixation by leguminous crops compared to S sources without N, such as polyhalite.