Product Type, Rice Variety, and Agronomic Measures Determined the Efficacy of Enhanced-Efficiency Nitrogen Fertilizer on the CH4 Emission and Rice Yields in Paddy Fields: A Meta-Analysis

Enhanced-efficiency nitrogen fertilizer (EENF) is a recommend for rice production because of its advantage on improving use efficiency. However, efficacy CH4, the dominant greenhouse gas, emission from fields showed great variation under field conditions. And factors influencing are still unclear. We synthesized results 46 studies and analyzed impact product type, variety, primary agronomic measures (rice cropping system, (N) application rate, water management options) effectiveness EENF CH4 yield. Overall, EENF, including inhibitors (IS) slow/control-released (S/CRF), significantly reduced by 16.2% increased yield 7.3%, resulting in significant reduction yield-scaled 21.7%, compared with conventional N fertilizer. Nitrapyrin, DMPP (3,4-dimethylpyrazole phosphate), HQ (Hydroquinone) + Nitrapyrin relative higher mitigation than other products; lower products. The response hybrid varieties to IS S/CRF was greater that inbred varieties. all three systems, highest late season double system. Whereas, did not reduce seasons single system rice-upland crops rotation when rate less 100 kg ha?1, affect ha?1 or above 200 ha?1. Continuous flooding unfavorable mitigate enhance These emphasized necessary link products practices assess their emissions