Beyond the trees: Exploring the determinants of intercrop management intensity in smallholder immature rubber systems in Thailand

Résumé fourni par la source

CONTEXT Ensuring natural rubber production while minimizing negative impacts in rubber-based cropping systems is a major challenge that must be addressed from the immature period, which typically lasts 6–7 years before tapping begins. Management during the immature period is critical to ensure optimal plantation long-term development. Intercropping is widely practiced in the inter-rows during the first four years after planting, with varying levels of management intensity. While previous studies have examined the adoption of intercropping in immature rubber plantations, what determines intercrop management intensity remains unexplored. OBJECTIVE The aim of this study was to explore the determinants of intercrop management intensity in smallholder immature rubber plantations, focusing on three technical operations: planting density, mineral fertilizer rates, and herbicide use. METHODS Semi-directive interviews were conducted with 73 farmers managing rubber plantations intercropped with cassava in Buriram province, pineapple in Rayong province, or upland rice in Trang province, Thailand. Based on a literature review, 38 variables representing the external and internal farm context, as well as other livelihood strategies, were identified as potential determinants of intercrop management intensity. Random forest algorithms were used to select the most contributing variables for each technical operation, and Classification and Regression Trees were then applied to assess how these variables shaped management intensity. RESULTS AND CONCLUSION Twelve variables emerged as determinants of the technical operations studied. They were linked to the external context of the farm (i.e. soil problems, difficulty of weed species management, and financial support for rubber replanting), the internal context (e.g., savings, tractor ownership) and livelihood strategies (other crop areas). Each determinant was associated with only one technical operation, and its effects were mostly not distinguishable across intercropping systems. Some determinants, such as participation in training programs on intercropping, may represent promising entry points for promoting the transition toward more sustainable rubber-based systems, with potential implications for policy design and implementation. SIGNIFICANCE By identifying factors associated with intercrop management intensity, this exploratory study provides critical insights for understanding the levers and barriers to adopting and scaling more sustainable practices in immature rubber-based systems. These findings can inform both local extension services and broader policy initiatives aimed at improving sustainability in smallholder rubber production.

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