Enhancing smallholder farmers’ willingness to adopt organic fertilizer in Zhejiang Province, China: a configurational analysis of pathways

Abstract

Organic fertilizer substitution can reduce agricultural non-point source pollution, but subsidy programs in China often exclude smallholder farmers. This study evaluates the effectiveness and feasibility of subsidizing smallholders in Zhejiang Province and identifies combinations of internal factors associated with their willingness to adopt organic fertilizer substitution. Data were obtained from 288 smallholder farmers in 11 green agricultural pioneer counties. The contingent valuation method and willingness to accept were used to estimate expected subsidy levels under different substitution ratios. The theory of planned behavior and fuzzy-set qualitative comparative analysis were then integrated to examine six internal conditions: ecological rationality, economic rationality, exemplary norms, directive norms, competence perception, and policy perception. Subsidies increased stated willingness, and the estimated willingness to accept was generally below prevailing subsidy levels. At a 40–60% substitution ratio, the expected subsidy was 124.74 Chinese yuan per metric ton. No single internal condition was necessary for high willingness. Instead, six configurations formed four pathways: Learning, External Normative, Resource-oriented, and Benefit-oriented. These pathways show that technical learning and competence, institutional and peer influence, access to on-farm organic resources, and perceived economic and ecological benefits operate in different combinations across heterogeneous smallholders. Policy should (1) implement tiered subsidies according to farm scale and substitution needs, (2) refine agricultural technology extension by combining accessible training with online and offline communication, and (3) strengthen social learning through peer demonstration and locally trusted information channels. The configurational approach offers a differentiated basis for promoting organic fertilizer substitution in comparable smallholder regions.