Desert Development: How Does It Relate to Anti Desertification Measures? - Combating Desertification in Asia, Africa and the Middle East - page 416

Fig. 20.4 Dynamics between people, livestock, cropland and desertification

The Han system of agriculture had been developed in the more reliable climatic
zones of east and central China and was originally confined to the more humid
regions of China. They were not always suitable for extrapolation to the arid zone,
despite the availability of hitherto untapped sources of snow melt water from the
mountains of west China. Soils there were high in exchangeable sodium and had
high pH. Irrigation and drainage had to be quite sophisticated. Often they were not.
Salinization often led to abandonment of vast areas because irrigation/drainage
techniques were poor and water was frequently wasted (Zhu Zhenda and Lui Shu
1983 ). Often too, the installation of reservoirs led to reduced downstream flows of
rivers and to the creation of even drier conditions under which recruitment of trees
and shrubs to the desert environment was no longer guaranteed. Coupled with this
the harvesting of fuelwood by the new settlers soon destabilized the desert areas.
By the 1960s the westerly expansion of this system of agriculture that relied
on developing the artificial oases was well established. The system was pushed
westward and northward but by the 1980s major land degradation problems began
to emerge.
From 1949 successive episodes of “land conversion/reclamation” occurred: the
first in the 1950s and again in the early 1970s. As increasingly marginal lands
were brought into production, crop yields dropped and croplands were routinely
abandoned after two rotations. The ill-fated efforts during the Cultural Revolution
were particularly damaging. The inevitable consequence of the above land use
pattern included the loss of stabilizing vegetation cover, soil structure and moisture