Diversity, adoption and performances of inter-row management practices in immature rubber plantations. A review

Perennial cropping systems begin their cycles with a pluriannual immature period. Appropriate management, including the inter-rows, is essential for the long-term viability, and productivity of the plantation while reducing the length of the unproductive period. Despite its significant economic and environmental impacts, the immature period is still poorly characterized and rarely included in the assessment of perennial cropping systems sustainability. Rubber plantations are an interesting case, as a major perennial system in the tropics. Here we conducted a systematic review to identify (1) management practices in inter-rows of immature rubber plantations; (2) the variables used in the literature to analyze the adoption drivers of these practices and to assess their effects on plantation functionalities and performances; and (3) the main effects of diversification practices on plantation functionalities and performances. The major results showed that (1) different inter-row management practices, including a diversity of crops, are possible during the immature period; (2) adoption of diversification practices is driven by few global factors but mostly depends on the specific socio-economic and agroecological context; (3) diversification practices are usually assessed with respect to agronomic and economic performances, and their impacts are generally positive. We identified missing knowledge required for a comprehensive view on current inter-row management practices in immature rubber plantations. First, technical operations should be included in the characterization and assessment of inter-row management practices. Second, a multicriteria assessment framework is required to cover all the sustainability dimensions to guarantee the diffusion of more performant management practices. In order to include the diversity of perceptions of sustainability in rubber plantations, this multicriteria assessment should be based on relevant criteria that combine farmers' and scientists' points of view. Detailed characterization of current immature rubber plantations merged with multicriteria assessment will be essential for the design of more sustainable rubber tree cropping systems.