Characteristics of ammonia volatilization of slow release compound fertilizer in different pH values of purple soils

By using Venting method indoor incubation experiment, the ammonia volatilization and kinetic characteristics of uncoated slow release compound fertilizer(SRF) were studied with different pH values of purple soils. The results showed that the soil pH values had significant influence on ammonia volatilization of SRF, ammonia volatilization increased with soil pH values increasing, the order of them was calcareous purple soil>neutral purple soil>acidic purple soil. Compared with the large particle urea(PUR), SRF could significantly reduces rate and total amount of ammonia volatilization from soil, which were decreased by 14.2% and 7.18% in calcareous purple soil, decreased by 32.3% and 24.1% in neutral purple soil, and decreased by 76.8% and 10.7% in acid purple soil, respectively. In the three kinds of purple soils, the dynamics of ammonia volatilization of SRF could be quantitatively described by three equations: the first—order kinetics equation, Elovich equation and parabola equation, and could predict the ammonia volatilization of SRF with these models. SRF could reduce the loss of nitrogen fertilizer, then reduce envionment pollution.