This paper evaluates the impact of Zambia’s Farmer Input Support Programme (FISP) reform on the degree of crop diversification and crop rotation. The paper combines a rich two-wave panel of rural household survey data, high-resolution satellite rainfall data, and primary in-depth interviews with Agriculture Extension workers. The paper finds that expanding the number of crops supported beyond just maize positively impacted both the level of crop diversification and the intensity of crop rotation. These results show that reforms are potent in stimulating the adoption of climate-smart farming behaviours. However, the impact is undermined by the absence of functioning markets for alternative crops, the entrenched culture of mono-cropping maize, and the general lack of knowledge and resources necessary to adopt new technologies.