基于秸秆全量还田的不同耕作方法下稻麦生产的碳效率及收益评估

为探明江苏稻麦轮作农业的固碳减排效应，本研究以江苏沿江地区稻麦两熟田块为研究对象，利用基于秸秆全量还田的不同耕作方法下（麦稻宽行交互保护性耕作技术模式和稻麦周年机械化耕作方式）作物产量、系统物质投入以及人工投入等资料，估算稻麦生产的碳投入、碳产出、碳效率以及经济收益。结果表明：保护性耕作方式和机械化耕作方式下稻麦轮作系统年度碳投入总量分别为1836.5 kg/hm2和2290.5 kg/hm2，保护性耕作的种子、化肥以及机械的碳投入较低，但劳动力碳投入高于机械化耕作方式。两种耕作方式的年度碳产出总量分别为18.23 t/hm2和16.15 t/hm2，保护性耕作较机械化耕作增加了12.9%。年度的碳效率在两者之间也存在差异，保护性耕作的生产效率、生态效率以及经济效率分别较机械耕作提高了40.4%，40.8%和40.3%。另外，保护性耕作的年度纯收益为20.25×103 yuan/hm2，较机械化耕作增加了22.8%。说明秸秆全量还田下采取保护性耕作方法既可以提高碳效率也能增加经济收益，取得环境效益和经济效益的双赢。

An Evalucation of Carbon Efficiency and Economic Income under Different Farming Methods with Full Straw Returning

The object of this study was to investigate carbon sequestration potential of rice-wheat rotation system in Jiangsu Province. The rice-wheat cropping fields along Yangtze River in Jiangsu province were chosen to estimate the carbon input, carbon output, carbon efficiency and economic income in rice and wheat production, based on research data of grain yield, material and labor inputs under different farming methods with full straw returning, including wheat-rice wide-row alternative protective farming technology mode and annual mechanized farming for rice and wheat. The results showed that the amount of annual carbon input under protective farming (PF) and mechanized farming(MF) were 1836.5 kg/hm2 and 2290.5 kg/hm2 respectively. Compared with MF, carbon input of seeds, chemical fertilizer and machinery under PF was lower, but carbon input of labor was higher. The annual carbon output under PF and MF were 18.23 t/hm2 and 16.15 t/hm2, respectively, and PF was 12.9% more than MF. The annual carbon efficiency also had significant difference between PF and MF. Compared with MF, PF increased production efficiency, ecological efficiency and economic efficiency of Carbon by 40.4%, 40.8% and 40.3%, respectively. Besides, the annual income net of PF reached 20.25×103 yuan/hm2 and was 22.8% more than MF. The results indicated that the protective faming method with full straw returning could increase carbon efficiency and economic income and realize a win-win situation of environment benefit and economic benefit.