The introduction of sustainable practices is considered a win-win strategy for low-income countries because of its potential to simultaneously improve food security and address environmental issues. Despite the numerous studies that focus on the adoption of technological innovations, little work has been done on the socio-psychological behaviour of farmers with regard to sustainable practices. This study investigates smallholder farmers' intentions towards two practices: minimum tillage and row planting. The decomposed theory of planned behaviour is used as a theoretical framework to analyse the intentions. The findings reveal that attitudes and normative issues positively explain farmers' intentions to adopt both practices. Perceived control also has a positive significant effect on the intention to apply minimum tillage. When the intention is formed, farmers are expected to carry out their intention when opportunities arise. Moreover, perceived usefulness, social capital, and perceived ease of operation are also significant predictors of farmers' attitudes. Furthermore, social capital and training are factors that positively affect the normative issue, which in turn also positively mediates the relationship between training, social capital and intention. Finally, it is shown that neither the perceived resources nor information from the media significantly affect farmers' intentions. This paper thus confirms that social capital, personal efficacy, training and perceived usefulness play significant roles in the decision to adopt sustainable practices. In addition, willingness to adopt seems to be limited by negative attitudes and by weak normative issues. Therefore, to improve adoption of sustainable practices by smallholder farmers, attention should be given to socio-psychological issues. This could lead to improvements in farm productivity and enhance the livelihoods of smallholders.