Abstract：In a rice pot incubation experiment, the nitrogen transformation in the rice field surface water and potential nitrogen runoff loss risk were studied by applied urea with new nitrification inhibitor 3,4-dimethyl pyrazole phosphate (DMPP) in the powder soil and blue clayey paddy soil. The results showed that, in the powder soil and blue clayey paddy soil, the ammonium concentration were increased 24.8% and 16.7%, nitrate, nitrite and total inorganic nitrogen concentrations were declined 47.7% and 70.9%, 90.6% and 88.9%, 13.5% and 23.1% in the rice field surface water, respectively. So, the potential nitrogen runoff loss risk could greatly be decreased when the storm or field drainage happened. Furthermore, the electric conductivity value was also declined in the rice field surface water with the DMPP addition in the urea, decreasing the salt-ion runoff loss risk at the storm or field drainage and being beneficial for protecting the water body.
