A review of 400 studies shows all types of pesticides are harmful to soil biodiversity

Soil health hinges on robust communities of soil bacteria and insects. However, a recent science review published in Frontiers in Environmental Science shows that pesticides sprayed both above and below ground are dramatically reducing soil biodiversity. Covering 400 studies that included responses of 275 unique species including earthworms, beetles, ants, and ground nesting bees, this review found that in 71% of cases, pesticide use negatively impacted soil invertebrates, and pesticides of all types that are currently registered for agricultural use were found to be harmful. “By pesticide type, 74.9% of tested parameters were negatively affected by insecticides, 63.2% by herbicides, 71.4% by fungicides, 57.7% by bactericides, and 56.4% by pesticide mixtures.” This study is the first comprehensive review to explore the direct connection between soil invertebrates and the impacts that pesticides can have on their communities.

This work is critical for several reasons: 

1) There is much discussion in the scientific community about an ‘insect apocalypse” and how this threatens critical ecosystem function that human success relies upon, and this work reveals that pesticide use contributes to the widespread decline of insects, 

2) This works shows pesticide use must be reduced to utilize agricultural soils as a carbon sink to help fight climate change, because healthier soil stores more carbon and healthy soil requires below ground biodiversity, 

3) The U.S. EPA (Environmental Protection Agency) does not currently include impacts on soil biology in its risk assessments of pesticides, but this work shows that environmental impacts of pesticides include harm to soil life. Therefore, future risk assessments should include these parameters in their measurements, and

4) The implications of this review are that organic farming, which uses fewer and less toxic chemicals and only as a last resort, helps protect insects above and below ground, supporting soil health and overall ecosystem function.


Banner Photo Credit:  Matheus Queiroz, unsplash.com

Photo Credit:  Ingo Doerrie; unsplash.com