Regulation of the mycotoxin deoxynivalenol by Folsomia candida (Collembola) and Aphelenchoides saprophilus (Nematoda) in an on-farm experiment

• Highest numbers of Aphelenchoides saprophilus were found in presence of deoxynivalenol (DON) contaminated straw.
• Population density of Folsomia candida was generally higher after 4 weeks.
• Highest reduction of DON concentration was found in single species treatments.
• Activity of nematodes and collembolans promotes the decontamination of DON in soil.

A field experiment based on a minicontainer-system was conducted on decontamination as an ecosystem service provided by soil fauna (Folsomia candida, Collembola and Aphelenchoides saprophilus, Nematoda). The objective was to investigate if the introduced soil fauna is able to reduce the concentration of the mycotoxin deoxynivalenol (DON) in wheat straw. The minicontainers were filled with soil and either DON-contaminated or non-contaminated wheat straw. Soil fauna was introduced in different combination into the minicontainers (single-collembolan, single-nematode, mixed and a non-faunal control treatment) and placed into the topsoil (0 – 5 cm) of an arable field. Each treatment was replicated five times. After 2 and 4 weeks, soil fauna was counted and DON content was detected in soil and straw. Population density of A. saprophilus developed mostly when received DON-contaminated wheat straw. Individual numbers of F. candida was highest in the mixed, non-infected treatment after 4 weeks. DON concentration in remaining straw of the contaminated minicontainers was reduced in the single collembolan treatment and in the single nematode treatment after 2 weeks. In contrast, there was an increase of DON in the non-faunal control treatment and the mixed treatment. After 4 weeks DON concentration decreased throughout all treatments compared to the initial concentration. In soil, a DON concentration was measured throughout all treatments after 2 weeks, which was reduced significantly after 4 weeks. We conclude that nematodes and collembolans significantly contribute to the degradation of the mycotoxin DON in wheat straw and protect soil from DON contamination as an ecosystem service.