Role of microbial communities in fertility of soil of perennial tropical plantations: potentialities for oil palm plantations

The perennial plantations of rubber trees (Hevea brasilensis Muell. Arg.), oil palm trees (Elaeis guineensis) and coffee trees (Coffea L.) are economically important in South-East Asia. Despite some initiatives promot-ing organic farming, mineral fertilisers are predominately used for growing these crops, with huge economic and environmental consequences. It is well known that for many agricultural and horticultural systems, a healthy soil microbial community leads to healthier plants and increased yields. That can be explained by the extensive interactions between plant roots and soil micro-organisms that further affect plant nutrition either directly by influencing mineral nutrient availability, or indirectly through root-growth promotion enhancing uptake efficiency. The increased understanding of the roles of root- or rhizosphere-associated microbes in plant nutrition and/or crop yields has resulted in their promotion for use in agricultural production as alterna-tives or supplements to mineral and/or organic fertilisers. However, little information is available concerning perennial plantations. Moreover, there is an obvious lack of promotion of beneficial soil micro-organisms to farmers, associated with a lack of market penetration of microbial inoculants for limiting the use of mineral fertilisers. Our presentation describes how the soil micro-organisms could efficiently be used for improving and sustaining the production of perennial plantations in South-East Asia. Several examples will be given to illustrate the way forward and an example of oil palm plantations will be emphasised. (Texte intégral