Work Block 5 Coordinator: Mark Reed, University of Leeds, UK

Modelling where soil and water conservation technologies are effective and viable

When local stakeholders have selected promising soil and water conservation technologies for their area, and these technologies have been tested in field experiments, it may still be difficult to formulate recommendations for their use. For example:

• The experimental conditions for which selected technologies were tested are limited and do not reflect the variable conditions within a region. Rains may have been plentiful so that water conservation did not boost yields, or a terracing experiment was set up on a slight slope so that it remains uncertain how terraces would perform on steeper slopes;
• The time it takes for technologies to develop full effectiveness and benefits is longer than technologies can be tested during a five year research project. Build up of soil organic matter after changing tillage methods or crop rotations is a slow process, and long-term yield increases will not have been observed;
• Policymakers and extension services would like to know whether a technology performs across a range of conditions before committing to stimulating adoption. Apart from differences in environmental conditions and the time it takes to develop full benefits, the investment costs and access to markets are important factors influencing the viability of a technology.

Modelling offers an alternative and complementary approach to evaluate the likely biophysical effects of adopting different remediation strategies at a regional scale and their financial viability. ** expand here