This book reflects the results of more than ten years of cooperative research involving Wageningen Agricultural University (y. l AU) in the Netherlands, the Tropical Agricultural Research and Higher Education Center (CATIE; Centro Agron6mico Tropical de lnvestigaci6n y Ensefianza) in Costa Rica and the Costa Rican Ministry of Agriculture and Livestock (MAG; Ministerio de Agricultura y Ganadeda) as part of the Research Program on Sustainability in Agriculture (REPOSA) in the Central American country. The type of cooperation was unusual as it focused on both research and the education of students undertaking either M. Sc. thesis projects or a program of practical training in the various aspects of studying land use. Since funding was provided by W AU, a high degree of scientific autonomy was created that has clearly benefited the independent, scientific rigor of the work. Over the ten-year period, the program has changed from being a patchwork of various insulated specialist projects, into a truly interdisciplinary effort, leading to the development of innovative tools for analyzing land use on a number of geographical scales. These tools are presented in this book. Besides CATIE and MAG, cooperation with other Costa Rican partner institutions has been essential from the beginning, and this process of interaction has also evolved considerably over time.

Since the 1980s many developing countries have implemented macro-economic policy reforms to curb inflation, reduce fiscal deficits and control foreign debt. The policy instruments used, such as exchange rate adjustment, budget cuts, trade policy reforms, public expenditure reviews and privatisation, have different and sometimes opposite consequences for agricultural land use. During the same period awareness was growing that deteriorating soil quality could become a limiting factor to increase or even sustain agricultural production. As a result, food availability and even accessibility for large population groups in developing countries may be jeopardised in the near future. Recently, quantitative models have made useful contributions to understanding the impact of economic policy reforms on the sustainability of land use. They provide a consistent analytical framework to deal with complex issues such as the direct and indirect effects of economic, agricultural, environmental and population policies, the role of market imperfections in transmitting economic policy signals, and the interactions between soil quality, agricultural production and household economic decision making. Different types of models can be distinguished: bio economic models, focussing on the link between farm household decisions and the agricultural resource base, household and village models, examining the impact of the socio-economic environment on farm household decisions, and more aggregate models, analysing interactions between sectors and their implications for sustainable land use.

The need to increase food production, enhance economic growth and reduce poverty in an environmentally sustainable context is an issue of growing importance. This book addresses the linkages and tradeoffs involved in solving such key challenges.