An investigation into the possible relationship between the decrease in the number of meadow birds and the presence of pesticides on livestock farms in the Province of Gelderland, the Netherlands

In this study the presence of 664 pesticides and 21 anti-parasitic drugs was investigated in concentrated feed, manure and soil on 24 Gelderland livestock farms (15 conventional and 9 organic). Furthermore, a tree nursery participated in this study, from which the soil was examined.

In the three substrates, 134 different fungicides, herbicides, insecticides and biocides were found in ecologically relevant concentrations. No sample was free of pesticides. A total of 116 different pesticides was found on 16 conventional farms and 71 on 9 organic farms. Pesticide residues in organic concentrated feed were on average 3.7 times lower than in conventional concentrated feed. The levels in the soil and in the manure were much less different between conventional and organic. On 20 of the 24 cattle farms studied, no anti-­‐parasitic agents were found above the detection limit in the manure. These were found at three conventional farms and at one organic farm.

High concentrations of pesticides in manure and soil on livestock farms may be an important cause of the dramatic decline of many meadow bird species. Even on organic farms, the measured concentrations are higher than expected. The pesticides found enter livestock farms via purchased concentrates and straw.

The full report (in Dutch) can be found here