RESEARCH PROGRAM
Food production for growing populations in the tropics will result in more land under agriculture. As most of the arable land in the tropics is currently occupied, the pressure is on lands with infertile soils and currently occupied by tropical forests. The rapidly increasing numbers of smallholder farmers on marginal lands, will need technologies designed with a good knowledge of the biophysical, chemical, and physiological constraints to food and wood production. An expanded understanding of tropical soil management and conservation will also be crucial to the successful development of technologies for the rehabilitation and productive use of degraded and abandoned lands. Unsustainable cropping systems can be expected to have a global impact on society and the environment via increased migration, loss of biodiversity, and increased greenhouse gas emissions.
A key research challenge is to design and disseminate systems with appropriate crop associations and rotations that maximize soil cover, rooting depth and nutrient utilization efficiency. To make these systems attractive to farmers, I address both productivity and socioeconomic factors. Where farmers are unable to use external inputs, reduced-input production systems will be needed. The rediscovery, selection and use of traditional food crop species, the harnessing of the beneficial effects of mycorrhizal fungi and nitrogen-fixing symbionts, and the development and use of integrated nutrient and pest management strategies will enhance the resilience of these systems. I hypothesize that such systems will provide farmers with access to good amounts of calories and nutrients even during severe outbreaks of pests, drought, and years of low cash crop prices. My current research focuses on collaborative and interdisciplinary approaches with researchers and farmers to develop and test appropriate cropping systems in the context of farming landscapes in the Brazilian Amazon and Madagascar.