Title: Widespread occurrence of pesticides in organically managed agricultural soils—the ghost of a conventional agricultural past

Pesticides are applied in large quantities to agro-ecosystems worldwide. To date, few studies have assessed the occurrence of pesticides in organically managed agricultural soils, and it is unresolved whether these pesticide residues affect soil life.

This study screened 100 fields under organic and conventional management with an analytical method containing 46 pesticides (16 herbicides, 8 herbicide transformation products, 17 fungicides, seven insecticides).

Pesticides were found in all sites, including 40 organic fields. The number of pesticide residues was two times and the concentration nine times higher in conventional compared to organic fields.

Pesticide number and concentrations significantly decreased with the duration of organic management. Even after 20 years of organic agriculture, up to 16 different pesticide residues were present.

Microbial biomass and specifically the abundance of arbuscular mycorrhizal fungi, a widespread group of beneficial plant symbionts, were significantly negatively linked to the amount of pesticide residues in soil. This indicates that pesticide residues, in addition to abiotic factors such as pH, are a key factor determining microbial soil life in agroecosystems.

This comprehensive study demonstrated that pesticides are a hidden reality in agricultural soils, and the results show that they have harmful effects on beneficial soil life.

Citation: Judith Riedo, Felix E. Wettstein, Andrea Rösch, Chantal Herzog, Samiran Banerjee, Lucie Büchi, Raphaël Charles, Daniel Wächter, Fabrice Martin-Laurent, Thomas D. Bucheli, Florian Walder, and Marcel G. A. van der Heijden (2021). Widespread occurrence of pesticides in organically managed agricultural soils—the ghost of a conventional agricultural past? Environmental Science & Technology, 55 (5), 2919-2928.

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Article: WeedsNews6783 (permalink)
Categories: :WeedsNews:research alert, :WeedsNews:soil research, :WeedsNews:organic farming, :WeedsNews:pollution
Date: 24 March 2025; 7:31:47 pm Australian Eastern Daylight Time

Author Name: David Low
Author ID: adminDavid