EVALUATING THE SUSTAINABILITY OF A SMALL-SCALE LOW-INPUT ORGANIC VEGETABLE SUPPLY SYSTEM IN THE UNITED KINGDOM - Organic Agricultural Practices - page 28

Assessment of environmental impacts exclusively from the distribu-
tion phase reveals that the local distribution system provides signifi cantly
lower environmental impacts per functional unit for all of the impact cat-
egories considered (Table 6). The relative advantage of the case system
compared to the model system reached from 69% for the non-renewable
resource use up to 98% in the case of human toxicity potential.

TABLE 6: Environmental impacts per functional unit exclusively for the distribution phase
(the same for M-Low and M-High).

Impact Category Unit Case

Distribution

Model
Distribution

Relative Advantage
of Case System (%)

Non-renewable,
fossil and nuclear

MJ eq 23,783 75,923 69

GWP 100 kg CO 2 eq 1629 4890 67

Acidification, GLO m 2 92 469 80

Eutrophication aq. N, GLO kg N 0.73 3.74 81

Eutrophication aq. P, GLO kg P 0.00 0.05 91

Human toxicity HTP 122 6646 98

Terrestrial ecotoxicity TEP 2 21 92

Aquatic ecotoxicity AEP 513 1445 64

Phosphorus kg 0 0 71

1.6 DISCUSSION

1.6.1 LCA VERSUS EMERGY ASSESSMENT—HANDLING OF
CO-PRODUCTS

The assessment of sustainability of the organic low-input vegetable supply
system using emergy accounting and LCA has shown that the two meth-
ods lead to the same conclusion regarding the supply chain but differ to
some extent in the assessment of the production systems. The sometimes
contradictory results of the emergy and LCA results are to a large part
due to differences in how co-products, e.g., manure, are accounted for. In