Objective  Farmers’ behaviors of protecting black soil depend on the objective evaluation of soil quality and the correct usage of chemical fertilizer and other inputs. There is no final conclusion whether the relationship between them is “knowing then doing” or “doing then knowing”.

  Method  Therefore, based on the household survey data of 944 grape growers in Beizhen City, Liaoning Province, a theoretical model of farmers’ fertilization behavior and soil quality was constructed to empirically test the relationship between them. The simultaneous equation model was used to verify the formation mechanism of farmers’ soil quality cognition.

  Result  The results showed that farmers have abnormal cognition of soil quality, that is, fertilization behavior significantly and positively affected the cognitive level of soil quality, rather than soil quality cognition determined fertilization behavior. Further analysis showed that when the level of human capital and social capital of farmers was high, this abnormal phenomenon of cognition and behavior disappeared, indicating that the higher level of human capital and social capital is helpful to correct the cognitive deviation of farmers on soil quality. In addition, neighborhood effect played an important role in farmers’ fertilization decision-making process.

  Conclusion  Therefore, agricultural training activities should be carried out in depth, focusing on improving farmers’ knowledge literacy, setting an “example” force, promoting farmers to correctly understand soil quality, and then farmers take rational fertilization behavior.