不同再生稻栽培模式碳足迹与经济效益评估

Evaluating carbon footprint and economic benefit under different cultivation modes of ratooning rice

通过大田试验,在湖北省武穴市花桥镇设置不同再生稻栽培模式:常规人工插秧模式CK与2个机插秧优化栽培模式OM1、OM2,探究不同栽培模式下稻田甲烷(CH_(4))和氧化亚氮(N_(2)O)排放、碳足迹以及净生态系统经济效益,为再生稻低碳丰产栽培提供理论依据。结果显示,栽培模式显著影响CH_(4)排放,但对N_(2)O排放影响不显著;OM2模式CH_(4)周年累积排放量相比CK和OM1模式分别降低43.5%和26.3%;栽培模式显著影响水稻产量与碳足迹;与CK、OM1模式相比,OM2模式头季产量显著增加15.2%与5.8%;再生季产量显著提高44.2%和34.7%;优化模式OM2相对于CK与OM1显著降低了碳足迹,降幅分别为40.0%和24.0%;OM2模式净生态系统经济效益最高为20 768 CNY/hm^(2),分别是CK与OM1模式的1.38与1.28倍。研究结果表明,OM2相比其他模式降低了CH4排放和碳足迹,提高了水稻产量和净生态系统经济效益。

Ratooning rice as a cultivation mode of rice with low cost and high benefits has been pro⁃moted in China,but the effects of the mode on carbon footprint of rationing rice production are unclear.A field experiment was conducted to study the effects of different cultivation modes of ratooning rice including conventional cultivation mode(CK),two optimized cultivation modes(OM1 and OM2)on the emission of methane(CH_(4))and nitrous oxide(N_(2)O),grain yields,carbon footprint and economic benefits in cen⁃tral China.The results showed that the OM1 and OM2 modes were optimized from the perspectives of wa⁃ter and fertilizer managements,stubble height,straw treatment in the first season and winter management compared with CK.The cultivation modes significantly affected CH4 emissions but had no effect on N_(2)O emissions.OM2 significantly reduced the annual cumulative CH_(4) emissions by 43.5%and 26.3%relative to CK and OM1,respectively.Cultivation modes significantly affected grain yields and carbon footprint.Compared with CK and OM1,OM2 significantly increased the yields of first rice season by 15.2% and 5.8,and the yield of ratooning rice season by 44.2% and 34.7%,respectively.OM2 significantly decreased the carbon footprint by 40.0% and 24.0%relative to CK and OM1,respectively.The highest net ecosys⁃tem economic benefit of OM2 was 20768 CNY/hm^(2),which was 1.38 and 1.28 times of those of OM1 and CK,respectively.It is indicated that OM2 mitigates CH4 emissions,reduces carbon footprint,increases rice yields and improves NEEB compared with other modes.OM2 is a sustainable cultivation mode of ra⁃tooning rice with low-carbon emission,high yield and high economic benefit.It will provide scientific basis for cultivating ratooning rice with low carbon and high yield.