Reduction of Environmental Impacts of Plant Protection Products Is Possible

Zurich-Reckenholz, 14.06.2018 - Agroscope researchers investigated the risks and environmental impacts of plant-protection products (PPPs) in Switzerland’s main agricultural crops. They found that a targeted selection of active substances and systematic adherence to the principles of integrated plant protection can significantly reduce the risks and undesirable environmental impacts of PPPs.

Plant-protection products (PPPs) safeguard agricultural crop yields as well as product quality. However, PPPs also have undesirable side-effects for humans and the environment.

In a study, Agroscope researchers determined the effects of PPPs on organisms in water bodies, in the soil, and in the immediate vicinity of the fields (i.e. in the off-crop habitats) for five agricultural crops: oilseed rape, wheat, carrots, potatoes and sugar beet.

The typical treatment sequences for each of three cultivation methods with different treatment intensities were investigated: an average variant based on the Proof of Ecological Performance (PEPmean); a variant with a higher treatment intensity (PEPhigh); and a variant based on the cultivation guidelines of the Swiss quality-label organisation IP-SUISSE (IPS). The two methods of risk assessment and life cycle assessment were used for the evaluation (see below). The study was funded by the Migros Cooperative Association (MGB) and actively supported by IP-SUISSE.

Potential for Reduction Differs according to Crop

Compared to the typical treatment intensity in PEP (PEPmean), the cultivation methods based on IP-SUISSE guidelines had significantly-lower-to-similar risks and environmental impacts for PPPs. Reductions in oilseed rape and wheat, and in potatoes in some cases, were particularly marked. The greatest differences were noted in the off-crop habitats. The high-treatment-intensity methods (PEPhigh) had significantly higher environmental impacts or risks for several indicators. In general, Integrated Plant Protection approaches such as compliance with damage thresholds play a major role in reducing treatment intensity. At the same time, yield and quality losses must be avoided.

Need for a Differentiated, Comprehensive Assessment

In some instances, the results for the analysed environmental compartments (water, soil and off-crop habitats) differ significantly. A meaningful assessment of plant-protection strategies must therefore take all affected environmental compartments into account.

In the cultivation methods investigated, a wide range of PPPs are used to combat numerous pests and diseases. Nevertheless, our study showed that in most cases, just a single (or a very few) active substances have a decisive influence on risks and environmental impacts. This shows on the one hand that a differentiated analysis is essential, and on the other that forgoing the use of crucial active substances can bring about striking improvements.

The complementary assessment of environmental risks via risk assessment and environmental impacts via life cycle assessment conducted here enables a comprehensive evaluation, and supplies important decision-making bases for reducing undesirable side-effects on the environment.

Risk Assessment and Life-Cycle Assessment

The risk assessment allows us to gauge the ecotoxicological risks of PPPs whilst bearing in mind site- and application-specific factors. For this, we availed ourselves of the SYNOPS method, which was used to analyse the risks for aquatic and soil-dwelling organisms, as well as for beneficials and bees in the off-crop habitats.

The life cycle assessment (LCA) provides a generic assessment of aquatic and terrestrial ecotoxicity as well as an impact assessment for relevant environmental impacts whilst bearing in mind the upstream and downstream stages, based on a meaningful unit (here, 1 kg harvested crops). The PestLCI Consensus Model and the Impact Assessment based on USEtox and ReCiPe2016 were used to assess ecotoxicity. For the remaining environmental impacts, the analysis was conducted according to Agroscope’s SALCA method.

Address for enquiries

Thomas Nemecek, Deputy Head, ‘Life Cycle Assessment’ Research Group
Agroscope, ‘Agroecology and Environment’ Research Division
Reckenholzstrasse 191, 8046 Zurich, Switzerland
thomas.nemecek@agroscope.admin.ch, +41 58 468 72 54

Laura de Baan, Staff Research Scientist, ‘Ecotoxicology’ Research Group
Agroscope, ‘Plant and Plant Products’ Competence Division
Schloss 1, 8820 Wädenswil, Switzerland
laura.debaan@agroscope.admin.ch, +41 58 460 61 95

Carole Enz, Media Service, Corporate Communication Agroscope
Schloss 1, 8820 Wädenswil, Switzerland
carole.enz@agroscope.admin.ch, +41 58 460 62 72