Integrated Farming Systems at Different Scales 439crop-cultivation subsystem including cereal crops, vegetables and fruit; the second
is the breeding subsystem involving chicken breeding, duck breeding, pigs, milk
cow breeding and aquaculture; and the third is the industry-sideline production
subsystem, including a number of cottage industries for processing agricultural
products, such as a flour processing factory, a fodder processing factory, a soft-
drink production factory, a slaughter and meat processing factory and a sweet
porridge factory.
In order to solve the problems of shortage of firewood and link different com-
partments of the production system into an integrated system, one of the success-
ful experiments was the development of biogas. The biogas system consisted of
four components:
1 Straw of grain crops, residues of vegetables and by-products from food process-
ing were used to feed cows and pigs.
2 The faeces and urine from cows and pigs were put into biogas ponds as raw
materials for biogas generation.
3 Biogas was used for cooking, water-heating and lighting.
4 Biogas residues and liquids were used as fertilizer for fishponds, vegetables or
crop cultivation. Through this system, planting–animal husbandry–biogas
generation–planting, or planting–agricultural product processing–animal hus-
bandry–biogas generation–planting formed an ecological cycle with multi-
energy utilization and material recycling (Figure 18.3).
In addition, in the eco-village an intensive material recycling system was also devel-
oped at the household level (Figure 18.4). A biogas generation pond was built in
the homeyard, and connected to the toilet, pigsty and poultry breeding house. The
excrement of animals was mixed with residues of vegetables and straws from crops
Figure 18.3 General material flow in Liuminying eco-village (large cycle)