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

Integrated Farming Systems at Different Scales 429

1980 many scientists and organizations have undertaken homestead garden ecosys-
tem studies. Among the most significant is the Shijiazhuang Agricultural Moderniza-
tion Institute, CAS, which made special and systematic studies and published a series
of research articles. Numerous examples indicate that the land productive ratio of
homestead garden ecosystems is much greater than that of general farmland. On

Table 18.2 Analysis of nutrient balance in a plastic shed subsystem

Item Quantity/yr N P 2 O 5 K 2 O

Input material for cultivating oyster mushrooms 6683.40 37.26 65.12 46.42

Output of oyster mushrooms 5717.50 19.12 28.51 15.87

Consumed by residents 50.00 0.17 0.26 0.15

Export to market 5667.50 18.95 28.25 15.72

Residue after cultivating oyster mushrooms 4484.23 18.39 33.95 30.25

Pig feed 385.00 1.58 3.09 2.60

Stored compost returned to farmlands 4099.23 16.81 32.86 27.65

Table 18.3 Analysis of nutrient balance in a biogas digester subsystem

Item Quantity/yr N P 2 O 5 K 20

Inputs

Human faeces (fresh weight) 273.00 2.84 0.98 0.93

Human urine (fresh weight) 2190.00 9.42 1.32 6.13

Pig faeces (fresh weight) 3759.50 22.56 16.92 18.80

Pig urine (fresh weight) 5665.00 17.00 7.36 11.33

Total 51.82 26.58 37.19

Outputs

Biogas manure (dry weight) 1000.00 16.20 19.70 5.50

Biogas liquid (fresh weight) 2000.00 22.00 6.80 12.60

Total 38.20 26.50 18.10

Table 18.4 Analysis of nutrient balance in a pig pen subsystem

Item Quantity/yr N P 2 O 5 K 20

Input

Feed 3255.00 65.43 43.62 31.90

Output

Pig faeces (fresh weight) 3759.50 22.56 16.92 18.80

Pig urine (fresh weight) 5665.00 17.00 7.36 11.33

Pig catch (pork) 825.00 25.87 19.34 1.77