A meta-analysis was conducted on the main crops in the Loess Plateau regions to assess the changes in crop yield, water use efficiency, soil organic carbon, economic benefits, energy use and their response to no-till and straw mulching. The results indicated that no-till straw mulching (NTS) increased wheat and pea yield by 14.3% and 29.5% compared with tillage (T), respectively. Water use efficiency has been enhanced by 12% for maize under tillage straw mulching (TS) treatment, but decreased by 7.8% were for soybean under no tillage. The straw mulching treatment, regardless of tillage practices, significantly increased the surface soil (0–10 cm) organic carbon content, while similar effects were not found under no-till treatment alone. The analysis of carbon sequestration showed that the annual average benefits of carbon credit of farmland under NTS treatment was 2385.12 CNY ha. The four crop energy inputs were 21.01 GJ ha under T treatment, which was higher than NT and NTS treatments. Carbon balance analysis showed that T, TS, NT and NTS treatments had higher carbon emissions in wheat fields than other crops, with the highest value of 1196.2 kg ha under T treatment. For economic benefits, the average maize revenue under the NT treatment of the four crops reached 18,672.5 CNY ha, which is –860 CNY ha less than the average of the T treatment. The implementation of conservation tillage in the Loess Plateau region can significantly increase crop yield, improve water use efficiency, enhance soil carbon sequestration capacity, and increase economic and agroecological benefits on a system level.

中文翻译：

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黄土高原地区保护性耕作和秸秆覆盖对作物产量、水分利用效率、固碳及经济效益影响的荟萃分析

对黄土高原地区主要农作物进行荟萃分析，评估农作物产量、水分利用效率、土壤有机碳、经济效益、能源利用的变化及其对免耕和秸秆覆盖的响应。结果表明，与耕作（T）相比，免耕秸秆覆盖（NTS）使小麦和豌豆产量分别增加了14.3%和29.5%。耕作秸秆覆盖（TS）处理下的玉米水分利用效率提高了12%，但免耕处理下的大豆水分利用效率下降了7.8%。无论耕作方式如何，秸秆覆盖处理都会显着增加表层土壤（0-10厘米）的有机碳含量，而单独免耕处理则没有发现类似的效果。碳汇分析表明，NTS处理农田碳信用年平均效益为2385.12元·公顷。T处理下四种作物能量投入为21.01 GJ ha，高于NT和NTS处理。碳平衡分析表明，T、TS、NT和NTS处理的麦田碳排放量高​​于其他作物，其中T处理的最高值为1196.2 kg·ha。从经济效益来看，NT处理下四种作物的平均玉米收入达到18672.5元公顷，比T处理的平均收入减少了–860元公顷。在黄土高原地区实施保护性耕作，可以显着提高农作物产量，提高水分利用效率，增强土壤固碳能力，从系统层面提高经济效益和农业生态效益。