Large-scale anti-erosion projects in Africa often fail because farmers don’t see the use of them. They are based on the insights of scientists who see soil degradation and erosion as the cause of low productivity, whereas farmers see drought as the cause.
The change that farmers notice has indeed happened, but it is not big enough to be statistically significant. ‘But these are marginal areas’, says Slegers. ‘It’s quite possible that small changes do have noticeable consequences for the farmers.’
What is more, for the farmers, there is more to drought than a lack of rain. It is also important how drought-resistant the soil is, and how crops react. The farmers in Tanzania distinguish between dark, red and light soils, and they know the water retention capacity of the different soils. Slegers’ conclusion is that the ideas of scientists and farmers about the causes of low agricultural production are more compatible than has been assumed. Although farmers talk in terms of drought, they do take into consideration the state of the soil and the way the farmer treats it.
Slegers also asserts that past projects aiming to combat soil degradation were too large-scale. They focused on creating terraces, for instance, and this practice was at odds with the ideas and customs of the farmers themselves. For example, Slegers saw how Tanzanian farmers plant pumpkins or water melons between their maize. The large leaves of these plants help prevent evaporation of moisture from the soil. In Ethiopia, farmers use organic fertilizer which improves the water-retaining properties of the soil. ‘It is better for projects to work with such existing practices’, says Slegers. Joris Tielens
Monique Slegers received her PhD on 7th November. Her supervisor was Professor of Soil and Water Conservation, Leo Stroosnijder.