LAUSR

Abstract The application of animal manure contributes greatly to improving soil fertility and maintaining/increasing wheat yield; however, it is rarely used in China's wheat production. This distortion emphasizes the importance of comprehensive analysis of manure use from theoretical and practical perspectives. A meta-analysis on China's wheat production was therefore conducted to quantify the effects of animal manure applications (SNM: substituting chemical N fertilizer by manure under the same total N input; AMCF: additional manure based on the same chemical fertilizer) on wheat productivity, environmental costs, and economic profits, and a large-scale farmer survey was performed to explore the reasons for the low manure-use rate. Overall, soil organic carbon (SOC) content in SNM and AMCF increased by 21% and 32%, respectively, relative to using chemical fertilizer alone (control). For SNM, yield increased by 5–8% when chemical N fertilizer was substituted with manure at