不同稻作系統(tǒng)的單位經濟收益碳足跡 （kg CO2-eq yuan-1）

 

　　近日，華中農業(yè)大學宏觀農業(yè)研究院、植物科學技術學院農業(yè)生態(tài)研究團隊與中國農業(yè)科學院農業(yè)環(huán)境與可持續(xù)發(fā)展研究所合作研究，回答了不同水稻生產系統(tǒng)如何實現固碳減排的問題。

 

　　該研究基于農業(yè)生態(tài)團隊在湖北省不同試驗站采用統(tǒng)一的靜態(tài)箱-氣相色譜法測定的水稻-冬閑模式、水稻-油菜輪作模式、水稻-小麥模式、雙季稻（早稻+晚稻）和水稻-小龍蝦共作模式等水稻生產系統(tǒng)的CH4和N2O排放試驗數據，結合生物地球化學循環(huán)DNDC（DeNitrification DeComposition）模型，將觀測結果使用模型統(tǒng)一到相同環(huán)境背景進行比較模擬，并分別采用基于過程的生命周期評估（PLCA）方法和成本效益分析方法對生產系統(tǒng)的碳足跡和經濟效益計算，系統(tǒng)評估不同水稻生產系統(tǒng)不同減排措施下的經濟產出和碳足跡。

 

　　研究結果表明，每種水稻生產系統(tǒng)需要配置不同的減排措施，才能夠實現高收入-低排放，并且相同的措施在不同模式中的減排角色可能不同。該研究可為不同水稻生產系統(tǒng)增效低碳生產提供技術指導。

 

　　研究成果以“Comparing rice production systems in China: Economic output and carbon footprint”為題發(fā)表在Science of the Total Environment上，宏觀農業(yè)研究院凌霖博士后為第一作者，曹湊貴教授為通訊作者。上述研究獲得國家重點研發(fā)計劃項目和中央高?；究蒲袠I(yè)務費專項資金等項目的共同資助。

 

　　【英文摘要】

 

　　In recent years, many rotational and integrated rice production systems coupled with several greenhouse gas （GHG） emissions mitigation practices have been developed and adopted for demand of low carbon production. However, there have been only few studies about comparisons on the balance between high production and mitigation of GHG emissions in different rice production systems. We therefore aimed to evaluate economic output and carbon footprint of different rice production systems, based on several long-term experiments conducted by our lab. CH4 andN2O emission were measured by the same static chamber/gas chromatogram measurement procedure in different rice production systems, including rice-fallow, rice-rapeseed, rice-wheat, double rice, and integrated rice-crayfish production system. Then, we applied the DeNitrification DeComposition model to simulate CH4 and N2O emission over different years under the same condition for comparison. Carbon footprint was calculated following the process-based life cycle assessment （PLCA） methodology. The economic benefit of rice production systems was assessed by cost-benefit analysis. According to the analysis, the double-rice production system exhibited the highest intensity of carbon footprint （ICF = 4.14 kg CO2-eq yuan?1）， rain-fed treatment in the rice-rapeseed system had the lowest （ICF = 0.68 kg CO2-eq yuan?1）。 The intensity of carbon footprint in different treatments in the integrated rice-crayfish production system was around 0.8 kg CO2-eq yuan?1. Overall, the results of this case study suggest: （1） the proposed practices in different rice production systems are no straw returning （rice-fallow）， no-tillage without straw returning （rice-wheat）， rain-fed farming （rice-rapeseed）， no insect and no inoculation （double rice）， and feeding with straw returning （rice-crayfish）； （2） rotational and integrated systems can achieve high net output with low carbon emission; （3） reducing the amount of nitrogenous fertilizer application is the most important and effective GHG mitigation practice for rotational systems.

 

　　論文鏈接：https://doi.org/10.1016/j.scitotenv.2021.147890