Historical heavy metal pollution of Swiss vineyard and drained organic soils

Departure: ETH Zurich, 8.15

Return: ETH Zurich, ca. 19.00

Lunch break: from ca. 13.15 to 14.15

Number of participants: Minimum 20, maximum 30

Recommendations: Sturdy shoes sun and rain protection. Easy walking.

Cost: 100.- Swiss Francs/person (transport, lunch, snack bag, visits, trip guides)

Organizers: Stéphane Burgos, Liv Kellermann and Dylan Tatti (Bern University of Applied Sciences) and Emmanuel Frossard (ETH Zurich).

This excursion will present two major forms of historical heavy metal pollution of Swiss agricultural soils linked to: (a) the use of copper as fungicide in vineyards and (b) the application of organic wastes as soil amendments.

This excursion is going into the Seeland region. Thanks to the mild and sunny climate, this region was already a preferred settlement site of stone age pile dwellers, long before the Romans introduced wine production to Helvetia; and being located at the border between the French and German speaking parts of Switzerland, it has had a rich cultural and political history ever since.

In the first part of the excursion we will visit a vineyard on Mont Vully, beautifully located between the lakes of Murten and Neuchatel. Due to the intensive use of Bordeaux mixture in the past, vineyard soils are heavily contaminated with copper (Cu) in Switzerland as in other countries. Nowadays, the application of Cu has been reduced drastically due to the increasing use of synthetic fungicides and to a more targeted use of Cu based on better disease prediction. The breeding of new grape varieties with higher disease resistance will hopefully enable further reduction in the use of Cu-based fungicides. But the Cu problem is not the only aspect of viniculture that will be addressed in this excursion. Viniculture has a long history in Switzerland going back to Roman times, and vineyard soils are also interesting from a pedological point of view.

The second part of the excursion will bring us into the lowland next to Mont Vully, the largest former peatland area of Switzerland. This area was drained and converted to agricultural use in the late 19th century. To improve the fertility of the drained peat soils, organic wastes from the city of Berne were distributed on this land in the first half of the 20th century. The practice was discontinued in 1954 when the organic matter became more and more contaminated with non-organic materials such as broken pottery, glass and other household wastes. But only decades later, it was discovered that also considerable amounts of metals had been introduced into the soil with the application of the wastes. The discovery led to the largest remediation of metal-polluted agricultural soil in Switzerland.