Agriculture Reference
In-Depth Information
administrative unit as planning and management purpose in China. Four
indices of agricultural input intensity and six of output intensity have been
derived with principal component analysis at this level for the Beijing
mountainous areas using the amount of emergy of each agricultural input
and output derived from agricultural census data [24]. Their eigenvectors
are given in Tables 4 and 5. The several indices refl ecting agricultural
input and output intensity were dimensionless, and the meanings of these
indices according to their eigenvectors are shown in Table 6. The higher
the index value, the greater the agricultural input or output intensity.
TABLE 4:
Eigenvectors of the input intensity [24].
Components
IPC
1
IPC
2
IPC
3
IPC
4
Sunlight
0.990
−0.075
−0.083
0.018
Rain, chemical energy
0.983
−0.056
−0.086
0.070
Rain, geopotencial energy
0.932
−0.163
−0.159
−0.096
Earth cycle
0.991
−0.071
−0.086
0.028
Wind, kinetic energy
0.991
−0.071
−0.086
0.028
Soil loss
0.991
−0.071
−0.086
0.028
Agricultural electricity
−0.252
0.364
0.527
0.156
Nitrogen fertilizer
−0.102
0.792
0.165
0.448
Phosphorus fertilizer
−0.062
0.852
0.011
0.305
Potash fertilizer
−0.103
0.890
0.113
0.139
Compound fertilizer
−0.119
0.809
0.270
0.184
Pesticides
0.005
0.109
0.787
−0.103
Agricultural plastic mulch
−0.165
−0.024
0.673
0.180
Machinery power
0.003
0.619
0.348
−0.085
Human labor
0.140
0.344
0.620
0.494
Livestock labor
0.135
0.020
−0.034
0.875
Organic manure
−0.088
0.471
0.268
0.648
Seed
−0.090
0.761
0.234
0.425
