Pesticides Found Extensively Detrimental to Soil Organisms

Soil degradation, climate change, heavy tropical monsoonal rain and pests are some of the challenges young farmers face. Credit. IPS

A single handful of soil contains a huge diversity of anywhere between 10 and 100 million organisms and they all have important roles to play in the function of healthy soil such as nutrient cycling, soil structure maintenance, the regulation of pests and diseases, and carbon sequestration.

Pesticides are often applied directly to soil as drenches and granules and increasingly in the form of seed coatings. A comprehensive review of the impacts of agricultural pesticides on soil invertebrates has found that pesticide exposure negatively impacted soil invertebrates in 70.5% of 2,842 tested parameters. Nearly 400 studies were reviewed, involving 284 different pesticide active ingredients.

The review found that all classes of pesticides pose a clear hazard to soil invertebrates—by killing them, reducing reproduction and species diversity, impacting growth and cellular function, or other negative impacts. Insecticides had a negative impact on over 60% of the tested parameters in the field studies, followed by bactericides at 50% and fungicides around 40%. For tested parameters involving mixtures of pesticides, the negative impact was found in 55%. The organisms most negatively impacted by pesticide use were ground-nesting bees and parasitic wasps that provide natural pest control.

This review underscores the need for soil organisms to be represented in any risk analysis of a pesticide that has the potential to contaminate soil, and for any significant risk to be mitigated in a way that will specifically reduce harm to soil organisms and to the many important ecosystem functions they provide. The authors therefore call for the inclusion of a soil health analysis in the pesticide risk assessment process.

Source: https://doi.org/10.3389/fenvs.2021.643847

https://www.frontiersin.org/articles/10.3389/fenvs.2021.643847/full

- Third World Network