LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

PARALLEL SESSION 1C: ECODESIGN AND ENVIRONMENTAL MANAGEMENT 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
3. Results
Potential environmental impacts are provided on the Total Results and Detailed Results sheets. Results
are expressed by functional unit in six impact categories. In this study, results were for the three production
systems, including the reference situation from default data and a case study for each production system (Table
2), described as follows:
3.1. Tomato production in a multi-tunnel greenhouse
Results for the reference situation showed that the structure, fertilisers and auxiliary equipment were major
contributors to all impact categories. The structure made the greatest contribution to the impact categories
of abiotic depletion (50%), global warming (37%), photochemical oxidation (54%) and cumulative energy
demand (50%) due to the high amount of steel and plastic in the frame, covering and floor. Fertilisers were
the main burden in acidification (39%), mainly because of ammonia emissions into the air during their application;
and eutrophication (56%), because of nitrate emissions to water, since there was an open-loop irrigation
system. The auxiliary equipment had significant contributions because of substrate and electricity consumption,
between 16% and 39%, depending on the impact category. The climate control system made nil
contributions, as there was no heating. Pesticides and waste management stages made contributions below
3% in the total production system.
The case study for a smaller greenhouse, lower fertiliser doses and higher yield showed contributions below
the reference situation, between 13% and 37%, depending on the impact category. Structure contributions
decreased between 2% and 9% as the amount of metal and plastic was reduced. Nevertheless, relative
contributions of structure increased in the total production system. Reduction of fertiliser doses directly reduced
the contribution to EUP, as a lower amount of lixiviates reached aquifers. A higher yield made reductions
to all impact categories, as a mass functional unit was used.
3.2. Tomato production in a Venlo glass greenhouse
In this production system, a CHP was used for heating and electricity production. Energy allocation of
natural gas was used to determine the impact of using natural gas to heat the greenhouse (Torrellas et al.,
2012). The climate control system was the main contributor to all the impact categories, between 81% and
97% of the total in the reference situation because of the high natural gas consumption to heat the greenhouse.
The structure was the second burden and made contributions between 2.0% and 10% because of metal
and glass contributions. Fertilisers made contributions between 0.6% and 8.6% due to emissions during the
manufacturing process and ammonia emissions into the air after these fertilisers are applied to the soil. Auxiliary
equipment contributions were lower than 1.9% of the total, and those of pesticides and waste management
were all around 0%.
With a reduction of 35% of natural gas consumption, climate control stage contributions decreased significantly
in all impact categories between 22% and 33%. Nevertheless, the climate control system was still
the main burden, with contributions between 75% and 95% of the total.
3.3. Rose production in a Venlo glass greenhouse
The climate control system was the main contributor in the reference situation and in this case study because
of natural gas consumption for heating and electricity consumption for lighting. Contributions were
between 98% and 99% in the reference situation and the case study. The structure made contributions below
1.1% in both production systems. In the case study with diffuse glass, structural contributions increased
compared with the reference situation by between 4% to 16%, depending on the impact category, as extra
electricity was needed in the anti-reflective coating process. In this situation, because of the effect of a higher
yield, contributions to other impact categories decreased by 4% compared with the reference situation.
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