Abstract:
The addition of urease/nitrification inhibitors is an important measure to reduce greenhouse gas emissions in paddy fields. The interaction effects of biochemical inhibitor combinationsN-(n-butyl)thiophosphoric triamide (NBPT), N-(n-propyl)thiophosphoric triamide (NPPT) and 2-chloro-6-(trichloromethyl)pyridine (CP) and fertilization models (one-off and three-time fertilizations) on greenhouse gases (CH
4 and N
2O) emission flux were investigated from yellow clayey field during rice (
Oryza sativa) growth season using two factors randomized block design, and calculated global warming potentials (GWPs) and greenhouse gas intensity (GHGI). The results show that CH
4 and N
2O emission flux had obvious seasonal variation under different fertilization treatments. The three-time urea fertilization treatment significantly reduced CH
4 and N
2O emissions, GWPs and GHGI during rice growth season than those of one-off urea fertilization treatment by 13.5%, 20.7%, 14.4% and 25.0%, respectively. Nitrification inhibitor CP treatment significantly reduced the peak of N
2O emission flux, as well as CH
4 and N
2O emissions during rice growth season under different fertilization models. On the other hand, urease inhibitor NBPT/NPPT combined with CP treatment could more effectively reduce CH
4 and N
2O emissions, as well as GWPs and GHGI during rice growth season. Application of a new urease inhibitor NPPT alone or combined with CP had the similar greenhouse gas emission laws with NBPT during rice growth season. In conclusion, combined biochemical inhibitors and appropriate managements can guarantee the production of rice and effectively reduce greenhouse gas emissions from paddy field, therefore, it is a feasible fertilization practice for low carbon emission and higher yield of rice.