Contract farming can reduce transaction costs and improve agricultural productivity. With the establishment of stable and effective contractual relationships, not only have agricultural products been provided with a stable market, but the standardization, refinement, and branding transformation of agricultural products can also be realized, thus further promoting the progress of agricultural modernization. The willingness of farmers to renew their contracts is a key factor in maintaining long-term, stable cooperative relationships. This research has empirically verified the impact model of tie strength between companies and farmers in contractual agriculture on the willingness of farmers to renew their contracts and revealed the working mechanism of tie strength on sustainable participation of farmers in contract farming. This study has utilized the survey data from 286 agricultural households in Inner Mongolia, China, and the method of structural equation modeling（SEM）, with the following results:(1)Interaction and reciprocity have a significant positive influence on trust. (2)Trust has a significant positive impact on farmers' willingness to renew their contracts. Also, reciprocity and interaction have an indirect impact on contract renewal willingness through trust .(3)Perception of economic value can significantly increase the contract renewal willingness of farmers and plays a mediating role between trust and contract renewal willingness.Overall, on the basis of tie strength, this research has provided a new perspective for the investigation of the sustainable stability of contract farming and empirical evidence for the sustainable development of the contract farming supply chain.

China’s Grassland Eco-Subsidy Program has been implemented since 2011 to protect and sustain grassland resources and improve the economic situation of herders. In this case study, we evaluated the policy from the perspective of pastoral differentiations and their willingness to accept (WTA) the eco-subsidy. Using the contingent valuation method (CVM), we interviewed 410 herder households in the grass-livestock balance sub-policy zones across Inner Mongolia, and examined how their horizontal and vertical differentiation affected their WTA and compensation expectations in a sorted Logistic model and a Tobit model, respectively. Our findings suggest that horizontal differentiation of herders (variations of income sources and employments) promoted the WTA for eco-subsidy and inhibited the increase of compensation expectations. A large vertical differentiation extent (income disparity) lowered the WTA but raised expectations for payment levels. Besides, factors such as operating pasture area, precipitation, and supervision intensity had significant impacts. Grazing income remained the primary income source for most herder households, reflecting the characteristics of "the rational economic man." Our results suggest a need for policy improvements to guide herders towards becoming "rational ecological men.” By considering this differentiation, policymakers can better tailor the program to meet the needs and expectations of diverse herder households.