6. More People, Less Erosion

“Necessity is the Mother of Invention”

 Esther Boserup (1965)

   

The primary cause of soil degradation is erosion. The book “More People, Less Erosion” examines a single case study from Kenya in which the local people transformed their fortunes by restoring eroded soils through good soil management techniques.

Fig. 1 Front cover of the book “More People, Less Erosion”, written by Tiffen et al. (1994). The book examines a case study of successful physical soil restoration in Kenya

Before: 1930s

In the 1930s, the hilly, semi-arid Machakos district in Kenya was heading towards desert, due to soil erosion. At this time, land was plentiful and people were few. Rather than sustainably managing the land, it was easier and more economic for farmers to just degrade one area (mainly via overgrazing) and move on. Eventually, all the land became degraded.

What changed?

Between the 1930s and the 1990s the population in Machakos trebled, markets in Nairobi became accessible (due to improved transport links etc) and a fruit-canning factory was built nearby.

After: 1990s

Land was now a limited and more valuable resource. This motivated the local people to improve its productivity. As Esther Boserup famously put it “necessity is the mother of invention”. They terraced the hillsides, which retained soil and water and they planted fruit trees (to sell fruit to the canning factory), which further held the soil together. These two simple methods of physical soil management restored and enhanced soil quality and transformed the livelihoods of the local people.

Fig. 2 The rolling terraced hills of the Machakos District, Kenya (Source: Project Survival Media, photo by Joe Lukhovi, taken in March 2012)