A pilot study of tropical soil organic matter will be conducted. Field studies being conducted in Yurimaguas, Peru and in several other tropical agricultural sites will provide data on soil organic matter dynamics. Some of these data will then be used to modify a soil organic model developed for temperate zone agroecosystems so that it can be used in the tropics. The remainder of the data will be used to validate the modified model. The model is a cutting-edge synthesis of current thinking in soil biology and chemistry. Its application to tropical soils problems will provide much need integration of here-to-fore unsynthesized information on tropical soils and their responses to management. With this synthesis tool we should be better able to manage the often fragile soils of the tropics. The investigators involved in the pilot study are world- recognized experts in their respective fields. Dr. Sanchez has demonstrated, for almost two decades, his ability to work in remote field settings in Latin America. Institutional support at North Carolina State University and Colorado State University are excellent.