The effects of dynamic incentives on the recycling of livestock and poultry manure in a multiscenario evolutionary game

Accelerating the recycling of livestock and poultry manure is an important direction to control nonpoint-source pollution in the middle and lower reaches of the Yangtze River. Based on evolutionary game theory, this study analyzes the complex behavioral interaction between farmers and breeding enterprises. We define the ideal scenarios and clarify the influence of key variables on the equilibrium results. The results show the following: (1) Replication dynamic analysis and an evolution phase diagram show that the optimal behavior strategy of farmers and breeding enterprises is organic fertilizer and recycling, and the evolutionary game between the parties tends toward the optimal solution. (2) When the government subsidy was mu=0.55, farmers' and breeding enterprises' strategies tend to reach the optimal equilibrium the fastest after 3 weeks and 1 week, respectively; when government administrative efficiency was k=5, farmers' and breeding enterprises' strategies tend to reach the optimal equilibrium the fastest after 10 weeks and 1 week, respectively. (3) Taking Anhua County of Hunan Province as an example, during the period of 2018-2020, the subsidy standard gradually increased from 25 to 45%, and the administrative efficiency increased by 63.3%. The enterprises involved in reconstruction to recycle waste increased by 218.9% and 132.2% in 2018-2019 and 2019-2020, respectively, which verifies the effectiveness of the evolutionary equilibrium results. The conclusions of this study can provide a reference for decision making regarding the fecal waste recycling of breeding enterprises and farmers.