How farmers learn to change their weed management practices: Simple changes lead to system redesign in the French West Indies

Herbicides used in agriculture pollute water worldwide. However, several weed management alternatives can reduce herbicide applications. The understanding of interactions between agronomics and the learning and social processes that favor changes in practices on a territorial scale is still far from complete. Despite the call for systemic change approaches, most studies are still based on technology transfer. Research and extension services provide references on alternative weed management practices and promote their use among farmers. We surveyed 33 farmers in a 45 km2 tropical catchment plus five institutional extension services. We analyzed changes in weed management practices on the 33 farms belonging to three different agricultural chains: local diversified horticulture, sugarcane, and export banana. For each change, we analyzed the learning processes and the networks involved in information exchanges. First, we show that the complexity of the practices promoted by extension services limits their adoption. Second, we show that simple practices adopted by farmers are part of a slow trajectory of change involving the gradual acquisition of knowledge. A redesign of cropping systems can emerge as the result of a gradual adding of complexity in practices and/or a specific systemic change on a cropping system scale. Sharing knowledge and resources in a non-competitive way speeds up changes among farmers sharing resources and promotes the redesigning of cropping systems. Third, we show that the structure and functioning of relational networks limit changes in practices on a watershed scale. We thus recommend that innovation design should incorporate co-designing of the pathway of change, by designing a succession of simple changes rather than a complex final system only. We recommend including non-competitive resource pooling among farmers in the co-designing of innovation.