Wetenschap - 11 oktober 2001

Integrated models provide policy makers with useful tools

Integrated models provide policy makers with useful tools

Land use can be improved by applying models which are dynamic and incorporate the knowledge of local experts such as agricultural extension workers. Huib Hengsdijk looked into ways of improving existing land use models.

Technical models of agricultural land use can be useful tools for policy makers. Wageningen University developed this kind of model during a research project on sustainability of agriculture in Costa Rica, where it had an office until recently. Two land use models were developed there, PASTOR and LUCTOR. Hengsdijk refined these models by incorporating process knowledge to make the models dynamic rather than static, and locally specific data, such as the amount of labour needed to grow certain crops, or the quality distribution of fruit produced under different conditions.

Local knowledge, a mixture of what government agronomists, extension officers and farmers themselves know about the local agrosystem, is often not well documented in developing countries. This knowledge is made explicit in PASTOR and LUCTOR, the advantage then being that it is transparent and open to critical review by others, explains Hengsdijk. He also adjusted the models to make them capable of interpreting data in a more dynamic way. On soil fertility, for example, the models assumed static conditions, whereas soil fertility is in a continuous state of flux between enrichment and depletion nutrients.

Hengsdijk calls his work an engineering approach, providing an improved theoretical basis to the existing models. What Wageningen is good at is educating engineers who can integrate various technical research disciplines.

Who benefits from this? Local policy makers, as the models can give them an idea of the technical possibilities for land use in their area given production, conservation or environmental objectives. Policy makers can then use this information to work directly on creating the social or economic conditions to realise their goals.

Joris Tielens