The Environmental and Social Costs of Improvement 31addicted to subsidies which normally come as part of development projects.’
(Sanghi, 1987).
The impact of these programmes has been to make many things worse. A fail-
ure to involve people in design and maintenance can create considerable long-term
social impact. The enforced terracing and destocking in Kenya, coupled with the
use of soil conservation as a punishment for those supporting the campaign for
independence, helped to focus the opposition against both authority and soil con-
servation (Pretty and Shah, 1994; Gichuki, 1991). This led, after independence, to
the deliberate destruction of many structures because of their association with the
former administration (Anderson, 1984). In neighbouring Somalia, a large Food
and Agriculture Organization (FAO)-funded project constructed dams during the
1970s to check gullies, but because of poor construction, many collapsed or
diverted the floods, so accelerating gully erosion instead of preventing it. This
induced widespread disenchantment amongst local people for all conservation
projects that followed (Reij, 1988). Such attitudes are a critical constraint for many
current soil conservation programmes.
The Loss of Biodiversity
Why farmers prefer diversity
Farmers of traditional and low input agricultural systems have long favoured diver-
sity on the farm. Today, there is still a huge variety of mixtures cultivated, includ-
ing cereals, legumes, root crops, vegetables and tree crops. In Africa more than 80
per cent of all cereals are intercropped, producing in some cases highly complex
patterns on the ground, with up to 20 species grown in close proximity (Vander-
meer, 1989; OTA, 1988). In Latin America, about 60 per cent of maize is inter-
cropped and 80–90 per cent of beans are grown with maize, potatoes or other
crops (Francis, 1986). In one field in the Andes in Peru, Robert Rhoades recorded
some 36 potato varieties growing in 13 rows (Rhoades, 1984). These were all
shapes and sizes, and a variety of colours, including black, red, blue, purple, yellow
and white. Altogether some 3000 traditional varieties are still grown by Andean
farmers.
In very variable conditions, farmers rarely standardize their practices. They
maintain diversity, develop a variety of strategies and so spread risk. Mixtures of
crops and varieties clearly provide farmers with a range of outputs, and also repre-
sent logical approaches to coping with variable environments. Mixed crops can
also be less variable in time and space, and combined yields are often greater, par-
ticularly if differences in root and shoot geometry allow the crops to use light,
nutrients and water more efficiently (Vandermeer, 1989; Francis, 1986; Rao and
Willey, 1980; Trenbath, 1974). Intercropping can reduce weed problems, so influ-
ence labour requirements; returns to labour can be increased; and erosion and run-
off may be reduced by the greater ground cover given by the mixture (OTA, 1988).