The contributions of enchytraeids and earthworms to the soil mineralization process in soils with fungicide

Abstract

Pesticides may harm soil organisms such as earthworms and enchytraeids, but knowledge is lacking on their relative sensitivity to these chemicals and the consequences on soil functions. The aim of this study was to assess the impact of exposure to a commercial fungicide formulation (Swing® Gold, containing dimoxystrobin and epoxiconazole) on the function of earthworms (Aporrectodea caliginosa) and enchytraeids (Enchytraeus buchholzi) in soil organic matter (SOM) mineralization. The soil organisms were incubated alone and together in a 26-day laboratory experiment. At the recommended field rate, the fungicide induced a decrease in the SOM mineralization and a delay in the maximum daily CO 2 emissions compared to the control soil without fungicide. Soil fauna also influenced SOM mineralization with a higher cumulated CO 2 release after 26 days in the control soil with earthworms (by 21%) than without fauna. When both earthworms and enchytraeids were present, SOM mineralization did not increase, and there was a negative effect on earthworm weight gain. Finally, an alteration of fauna influence with treatment was observed from day 19, meaning that the effect of fauna on SOM mineralization changed with fungicide treatment. Earthworms no longer promoted SOM mineralization when fungicide was present at three-fold the recommended field rate. The effects of enchytraeids on SOM mineralization were similar with and without fungicide exposure. This study underlines the importance of considering the relative sensitivity of soil organisms to environmental factors and interactions between them when assessing soil functioning.

Entomopathogenic fungi based microbial insecticides and their physiological and biochemical effects on Spodoptera frugiperda (J.E. Smith)

“…The search for dependable biological control agents to supplement the use of chemical control began in the early 1980s, when it was discovered that the majority of the insects being managed via chemical control were developing resistance to various types of chemical insecticides and that such chemicals were having a negative impact on beneficial soil living organisms, particularly earthworms ( Pelosi et al., 2021 ). Earthworms are considered a crucial soil indicator species due to their ability to significantly alter the chemical properties of the soil and improve overall soil health ( Tondoh et al., 2007 ; Yuvaraj et al., 2019 ; Yuvaraj et al., 2020 ; Yuvaraj et al., 2021a ; Yuvaraj et al., 2021b ).…”

Chronic exposure to tebuconazole alters thyroid hormones and plumage quality in house sparrows (Passer domesticus)

“…Among vertebrates, birds are particularly relevant to study this question because many bird species exploit or live near agricultural areas and are potentially exposed to triazoles through multiple routes of exposure (Robinson, 2004;Lopez-Antia et al 2016;Fernández-Vizcaíno et al 2020Ortiz-Santaliestra et al 2020;Angelier et al 2023). This contamination is likely associated with chronic exposure to low concentrations of triazoles, for example in water, soil, air and seeds (e.g., Kahle et al 2008;Rokbani et al 2019;Pelosi et al 2021;Lopez-Antia et al 2016. In this context, specific bird species (e.g., non-migratory species) can be relevant sentinel species of agroecosystems because they rely on this specific environment to complete their annual life cycle.…”