Table 3-.
Emergy synthesis and input structure of the commercial and subsistence rapeseed production systems (sej ha−1) except as noted.
| Unit | Transformity | Refs. for transformity | Emergy (sej ha−1) | Distribution | |||
|---|---|---|---|---|---|---|---|
| Commercial | Subsistence | Commercial | Subsistence | ||||
| Renewable environmental inputs(R) | |||||||
| Solar energy | J | 1.00E+00 | Definition | 4.00E+13 | 3.28E+13 | 0.10% | 0.13% |
| Wind, kinetic energy | J | 1.25E+03 | Campbell, and Erban, 2017 | 8.03E+12 | 6.58E+12 | - | - |
| Rain, chemical | J | 2.25E+04 | Campbell (man.) | 7.83E+14 | 4.57E+14 | - | - |
| Evapotranspiration | J | 2.88E+04 | Campbell (man.) | 1.00E+15 | 7.08E+14 | - | - |
| River water (chemical potential) | J | 3.61E+4 | Campbell (man.) | 1.95E+15 | 1.77E+15 | - | - |
| Subtotal | 1.99E+15 | 1.80E+15 | 4.81% | 7.31% | |||
| Renewable environmental inputs used in a nonrenewable way (N0) | |||||||
| Soil organic matter reduction | J | 9.36E+04 | Brandt-Williams, 2002 | 1.96E+16 | 2.67E+15 | 47.34% | 10.2% |
| Soil mineral erosion | g | 1.27E+09 | Odum 1996 | 1.80E+15 | 4.08E+15 | 4.36% | 16.53% |
| Subtotal | 2.14E+16 | 6.74E+15 | 51.71% | 27.35% | |||
| Purchased inputs(FR)&(FN) | |||||||
| Human labour | J | 2.22E+06 | Lu et al., 2009 | 5.06E+14 | 9.75E+14 | 1.22% | 3.95% |
| Machinery | g | 1.01E+10 | Campbell et al., 2005 | 2.30E+13 | 7.07E+12 | 0.06% | 0.03% |
| Fossil fuel and lubricant | J | 8.60E+04 | Bastianoni et al., 2009 | 6.62E+14 | 1.11E+14 | 1.60% | 0.45% |
| Nitrogen fertilizer | g | 3.09E+10 | Brandt-Williams, 2002 | 7.73E+15 | 4.64E+15 | 18.70% | 18.80% |
| Phosphorus fertilizer | g | 2.82E+10 | Brandt-Williams, 2002 | 4.23E+15 | 4.23E+15 | 10.24% | 17.15% |
| Potash fertilizer | g | 2.23E+09 | Odum, 1996 | 3.35E+14 | 1.12E+14 | 0.81% | 0.45% |
| Sulphur fertilizer | g | 2.05E+10 | Campbell et al. (2014) | 2.05E+15 | 2.05E+15 | 4.96% | 8.31% |
| Micro fertilizer | g | 3.91E+09 | Lan et al., 2002 | 1.17E+13 | 0.00E+00 | 0.03% | 0.00% |
| Organic fertilizer | g | 2.96E+08 | Odum, 1996 | 0.00E+00 | 3.55E+15 | 0.00% | 14.41% |
| Pesticide | g | 1.89E+10 | Hu et al., 2010 | 1.89E+13 | 9.45E+11 | 0.05% | 0.00% |
| Herbicide | g | 1.89E+10 | Hu et al., 2010 | 3.02E+13 | 0.00E+00 | 0.07% | 0.00% |
| Electricity | J | 2.31E+05 | This work | 7.97E+14 | 0.00E+00 | 1.93% | 0.00% |
| Installation of irrigation system | Rials | 2.50E+08 | Asgharipour et al. (man.) | 1.25E+15 | 0.00E+00 | 3.03% | 0.00% |
| Seed | Rials | 2.50E+08 | Asgharipour et al. (man.) | 3.30E+14 | 4.40E+14 | 0.80% | 1.78% |
| Subtotal | 1.80E+16 | 1.61E+16 | 43.49% | 65.34% | |||
| Total(U) | 4.13E+16 | 2.47E+16 | 100.00% | 100.00% | |||
| Output(Y) | |||||||
| Economic yield(E) | g | sej g-1 | This work | 7.24E+09 | 2.25E+10 | ||
| Economic yield(E) | J | sej J-1 | This work | 2.60E+05 | 8.02E+05 | ||
| Straw yield | g | sej g-1 | This work | 4.01E+09 | 1.25E+10 | ||
| Straw yield | J | sej J-1 | This work | 2.60E+05 | 7.97E+05 | ||
a
Transpiration is an integrated measure of all the renewable inputs required to support plant production (Odum, 1996), therefore it was chosen to represent R, to avoid double counting. In our view, the emergy of the solar radiation supporting photosynthesis must also be included for a complete accounting of the emergy of transpiration supporting rapeseed production.