Tropical Soil Biology and Fertility Programme (TSBF) TSBF was established in 1984 under the patronage of the Man and Biosphere programme of Unesco and the Decade of the Tropics initiative of the International Union of Biological Sciences (IUBS). The objective of the programme is to develop appropriate and innovative approaches for sustaining tropical soil fertility through the management of biological processes and organic resources. To achieve this objective, TSBF aspires to: make available to farmers and other land managers in the tropics methods of soil management which will improve agricultural productivity but conserve the soil resource contribute to increasing the carbon storage equilibrium in tropical soils in the face of global changes in land use and climate improve understanding of the role of biological resources in soil fertility and the sustainability of tropical land-use systems improve the research and training capacity of national institutions in the tropics in the fields of soil biology and management of tropical ecosystems. TSBF is a voluntary participatory international research programme whose members are committed to the concept that the fertility of tropical soils is controlled by biological processes and can be managed by the manipulation of these processes. Research is conducted at both the ecosystem level and the process level on the basis of two principles: that the capacity to manage soil fertility depends on a mechanistic understanding of the biological processes regulating nutrient flux, organic matter dynamics and soil physical structure maintenance, and that successful management for sustainable soil fertility must be implemented at the ecosystem level by integrating soil biological processes with those of human decision making in relation to all components of the ecosystem.