Purpose – The purpose of this paper is to investigate the influence of four components of social capital on farmers’ participative behaviour in collective actions for constructing and operating small-scale groundwater irrigation systems on the Guanzhong Plain, Shaanxi Province, China. Design/methodology/approach – The four components (social networks, social trust, social reciprocity and social participation) were derived by employing exploratory factor analysis. Logistic model was used to estimate the influence of these components on farmers’ participative behaviour. Information was obtained from a field survey covering six counties in 2011 of Shaanxi Province, China. Findings – The findings indicate that considering different components of social capital allows for a better understanding of farmers’ participative behaviour. The authors find that higher levels of social trust and social participation lead to a higher propensity for collective action, while social reciprocity reduces the probability of participation. Other socio-economic factors and farming characteristics such as education levels, cultivated area, cropping patterns and grain subsidies also have a significant impact. Practical implications – The findings suggest creating favourable conditions for communication and information exchanges between households, which enhance their trust of each other, and encourage farmers to participate in collective affairs. Moreover, supportive rules are necessary for the future development of collective action. The results of this study also have implications for national irrigation plans for small-scale irrigation facilities in other developing countries. Originality/value – A consideration of the different components of social capital allows for a more precise understanding of farmers’ participative behaviour.