50 The Global Food System
supporting dense populations, soil erosion continues to be a problem throughout
the world. To farmers, erosion reduces the biological productivity of soils and the
capacity to sustain productivity into the future. Although soil erosion is clearly
costly to economies as well as to farmers, it is difficult to calculate reliably the pre-
cise costs, though studies in Mali, Malawi and Java suggest that the costs to farmers
are substantial, representing 3–14 per cent of gross agricultural product.
One surprising cause of soil erosion is bad soil conservation programmes.
There are many examples throughout the world of impressive terracing and bund-
ing disappearing when local people have not been involved in planning and imple-
mentation. Poor terracing results in worse erosion. The impact of these programmes
has been to make many things worse. A failure to involve people in design and
maintenance can create considerable long-term social impact, inducing widespread
disenchantment among local people for all conservation projects that followed.
Biodiversity has fallen under modern agriculture. Farmers of traditional and
low input agricultural systems have long favoured diversity on the farm, and it is
only recently that fields monocropped to single species and varieties have become
common. The introduction of modern varieties and breeds has almost always dis-
placed traditional varieties and breeds. During the 20th century, some 75 per cent
of the genetic diversity of agricultural crops has been lost. Only about 150 plant
species are now cultivated, of which just three supply almost 60 per cent of calories
derived from plants.
Agricultural modernization has helped to transform many rural communities
in both industrialized and developing world countries. The loss of jobs, the further
shift of economic opportunity away from women to men, the increasing speciali-
zation of livelihoods, the increasing concentration of land in the hands of wealthy
villagers and urban investors, the growing gap between the well-off and the poor,
and the co-option of village institutions for the purposes of the state, have all been
features of this transformation. Cases are described of social change in Britain,
Japan, the US, Mexico, Indonesia, Tanzania and India. In all of these the social
costs have been substantial. Modern agriculture, though not the sole cause, has
clearly been a contributor to these changes.
References
AAN. 1993. Use of conservation tillage on the increase survey finds. Alternative Agriculture News
11(12), 2
ACORA. 1990. Faith in the Countryside. The Archbishops’ Commission on Rural Areas, London
Agarwal B. 1984. Rural women and high yielding rice technology. Economic and Political Weekly
19(13), A39–A52
Agarwal B. 1985. Women and technological change in agriculture: The Asian and African experience.
In Ahmed I (ed) Technology and Rural Women: Conceptual and Empirical Issues. George Allen and
Unwin, London
Agresti A. 1979. Analysis of Association Between 2,4,5-T Exposure and Hospitalised Spontaneous Abor-
tions. Environmental Health Sciences Centre, Oregon State University, Corvallis