Sustainable Agriculture and Food: Four volume set (Earthscan Reference Collections)

436 Modern Agricultural Reforms

3.77 million kg of fruits of different varieties harvested each year. The out-
put value of courtyard husbandry reached 80,000 yuan RMB in 1991. In
1990 a biogas engineering project was installed in ecological demonstration
households, using the dung of chickens, pigs and humans as raw material. A
13m^3 biogas pit was built in each household. These biogas digesters could
produce 1660m^3 biogas per year, which can save 9960kg of firewood. The
remaining liquid and sludge from biogas pits was returned to the fields as
good quality manure to improve soil fertility or to feed fish. Until 1991, 100
ecological demonstration households were constructed, accounting for 12
per cent of the total.
4 Establishing multi-step utilization and regeneration of agricultural by-products
and ‘wastes’. In the village there were 33 households raising 2,164,000 chick-
ens, and all the chickens’ faeces were used to feed fish, giving an annual saving
in fish fodder of 113.6kg. The second application of eco-engineering was a
mulberry–silkworm–pig–crop integrated production system: (i) mulberry was
cultivated to produce leaves used as forage for silkworm; (ii) the silkworm
chrysalis was used for raising pigs; and (iii) the faeces of pigs was returned to
the fields as fertilizer. These three integrated steps constituted a complete eco-
logical recycling chain. In 1991 the net income from silkworm cocoons, pigs
and grains reached 3.19 million yuan RMB, 58.91 per cent more than that of

1988. A third type of eco-engineering was a chicken–pig–mushroom–biogas
      integrated production system.
      5 Reorienting village enterprises toward environmentally healthy development.
      Following regulations for environmental protection, some lower-pollution or
      non-pollution enterprises were encouraged. Meanwhile, some strict measures
      were taken in heavy-pollution enterprises in order to control emissions. By
      1991 the wastewater emitted from heavy-pollution enterprises such as the
      Shandu Electroplating Factory and the umbrella manufactory had met the
      State’s Second-class Standard of environmental control (Table 18.9). After four
      years, significant environmental benefits had been attained. Table 18.10 shows
      the improvement in the quality of water through specific treatment, and
      Table 18.11 shows improvement in quality of soil. The treated rate of the
      ‘three wastes’ from village enterprises rapidly approached zero by 1991.
      6 Improving village infrastructures and life quality. According to the general
      development plan of 1988–1991, a number of new projects for strengthening

Table 18.8 The change in soil fertility from 1988 to 1991

Year Organic

matter (%)

Nitrates

(ppm)

Available

potassium (ppm)

Available

phosphorus (ppm)

1988 2.58 63.64 136.18 16.67

1991 2.63 70.64 141.72 16.81

RGR to 1988 (%) 1.94 11 4.07 0.84