Modifying nitrogen fertilizer practices can reduce greenhouse gas emissions from a Chinese double rice cropping system

•Polymer coating urea halved the GWP and improved crop yields.•Polymer-coated urea reduced CH4 emission significantly.•Nitrification inhibitors reduced N2O emission significantly.•N2O emissions accounted for 27–37% of total GWP over whole rotation.•N2O emissions and CH4 consumptions were notable during fallow period. Practical nitrogen fertilizers are required that simultaneously increase yield and reduce greenhouse gas (GHG) emissions from rice (Oryza sativa L.) paddies. A field experiment was conducted to measure methane (CH4) and nitrous oxide (N2O) fluxes in situ during two double rice-winter fallow rotations (2012–2014) under five different nitrogen fertilizer treatments: traditional urea (CK), polymer-coated controlled release urea (CRU), urea with N-Sever nitrapyrin (NU), urea with 3,4-dimethylpyrazole phosphate (DMPP), and urea with effective microorganisms (EM). The results revealed that GHG emissions ranged between 77.2 and 178.2kg CH4ha−1 and 4.18 and 10.11kg N2Oha−1 averagely over the whole rotation, and significant differences (P