The effect of conservation tillage in managing climate change in arid and semiarid areas—a case study in Northwest China

Climate change and agriculture are strongly related. The management of farmland can influence a variety of agro-ecological processes and affect greenhouse gas (GHG) emission. Based on reported data, this study conducted a meta-analysis to evaluate the role of conservation tillage (CT) in managing climate change in Northwest China. The results indicated that CT significantly improved the concentration of soil organic carbon (SOC), crop yields, and crop water use efficiency (WUE) compared with traditional tillage, and the practices with straw return were significantly higher than those without straw return. With an extended duration of the management, the SOC sequestration of each CT practice showed an increasing trend, but the crop yield did not show an obvious trend. After 5 ~ 10 years and more than 10-year management, CT practices reduced GHG emissions by 5.40 ~ 16.16 t CO2-eq∙ha−1 and 8.22 ~ 21.53 t CO2-eq∙ha−1 compared to traditional tillage, respectively. In most CT practices, winter wheat-summer maize rotation (W-M) planting pattern had the best SOC sequestration, and spring wheat showed the highest increasing of yield and WUE. More specifically, compared to traditional tillage, the SOC concentration under W-M increased by 10.15 ~ 20.09%, and the yield and WUE under spring wheat increased by 6.87 ~ 17.83% and 8.82 ~ 46.32%, respectively. In conclusion, CT played a positive role in tackling climate change in Northwest China.