Summary

Environmental LCA assessment of the Swiss federal program "extensive

production of cereals and rape seed"

The environmental impact of the extensive production of cereals and rape seed (Extenso) was analysed by means of life cycle assessment (LCA) on behalf of the Swiss Federal Office for Agriculture (FOAG). Subsidies are granted under the Extenso program when the use of fungicides, insecticides and growth regulators is renounced.

The network of ecological pilot farms (for the years 1994-1996) served as the main data basis for the study. The data cannot be considered as being representative of the current situation for cereals and rape seed production, but the cost frame of the project would have been exceeded through their actualisation. Indeed the lack of up-to-date and representative agro-environmental production data is a general problem of the ecological evaluation. For this reason, particular attention was paid to this fact when analysing the results.

The following cropping variants were analysed for wheat, barley and rape seed: conventional, integrated and organic farming, Extenso and No-Extenso intensities, mineral and organic fertilisation as well as plain and hill production regions. The Extenso program brought about an up to 50% reduction of the quantity of the spread plant treatment products (PTP) as well as a yield loss between 13% and 23%. It mitigated the ecotoxic effects of PTP on aquatic and terrestrial systems. However, this effect was partly caused by a reduced application of herbicides and was dominated to a large extent by the impact of heavy metals (coming first of all from fertilisers). With respect to biodiversity (expert opinion), the Extenso program is primarily favourable for rape seed production. For all other environmental impacts however (energy consumption, global warming potential, eutrophication, acidification, human toxicity and soil fertility [expert opinion], there were no assured advantages.

Large differences were observed between the different farming methods (conventional, integrated, organic) and for the most investigated environmental impacts. They were mainly caused by the farming system and through fertilisation. These factors were revealed to be much more important than the Extenso program. It is concluded that the Extenso program induced a reduction of the PTP use, but that it brings only minor advantages from the overall environmental point of view. Provisory recommendations were drawn from the study with respect to additional measures for the evaluation and the improvement of the Extenso program (better database, integration of new aspects). The following adaptations and supplements should be analysed: Taking into account of herbicide use and fertilisation, extension to other crops, narrow selection of active ingredients of pesticides and re-examination of five of them (chlorothalonil, isoproturon, dimefuron, methabenzthiazuron and lambda-cyhalothrin).

According to the ISO norm 14040 on Life Cycle Assessment, the present study should be subjected to an independent critical review. However, since the authors of the report and the project supervision were of the opinion that beforehand the production data should be actualised in order to improve their representativeness, it was decided to postpone it. Consequently, the study must be considered as a proof of the adequacy of LCA to evaluate the Extenso program. It serves to recognise the potential environmental impacts of the investigated crops and to identify the likely contribution of the program to the promotion of an environmental friendly agriculture. However, it may not be the basis for any decision for the future configuration of the Extenso program.