Toxicity of AMPA to the earthworm Eisenia andrei Bouché, 1972 in tropical artificial soil

Abstract

Aminomethylphosphonic acid (AMPA) - one of glyphosate’s main metabolites - has been classified as persistent in soils, raising concern regarding the widespread use of glyphosate in agriculture and forestry. Glyphosate may have negative or neutral effects on soil biota, but no information is available on the toxicity of AMPA to soil invertebrates. Therefore our aim was to study the effect of AMPA on mortality and reproduction of the earthworm species Eisenia andrei using standard soil ecotoxicological methods (ISO). Field-relevant concentrations of AMPA had no significant effects on mortality in acute or chronic assays. Except at the highest concentration tested, a significant biomass loss was observed compared to controls in the chronic assay. The number of juveniles and cocoons increased with higher concentrations of AMPA applied, but their mean weights decreased. This mass loss indicates higher sensitivity of juveniles than adults to AMPA. Our results suggest that earthworms coming from parents grown in contaminated soils may have reduced growth, limiting their beneficial roles in key soil ecosystem functions. Nevertheless, further research is needed to better understand the mechanisms underlying the sublethal effects observed here.

Effect of glyphosate application on soil quality and health under natural and zero tillage field condition

“…However, repeated and time-prolonged applications with glyphosate (as for RF4 and RF5) had an adverse effect on the biological properties of the soil and on the microbial population, leading to lower counts (although maybe remaining more specialized cells regarding the glyphosate degradation, rising AMPA as a consequence). There was a negative impact of AMPA in the soil microbial community as that reported in earthworms (Domínguez et al 2016) and also in the soil's structure, evidenced by an inverse correlation of AMPA with TAM, DHA, and WSA. Also, the separation of sample RF3 from the group of biological indicators and nutrients, and its closeness to samples with a longer history of application and growing concentrations of AMPA showed a decline in quality as glyphosate application events proceeded.…”

Soil ecotoxicology in Latin America: Current research and perspectives

“…Typical exposure temperatures include 23, 25, or 28 °C , reflecting the tropical climate in most of the Latin America territory. In southern Brazil, where subtropical climatic conditions prevail, the recommended temperature was 20 °C . Pesticide ecotoxicology for soils in this region (Table ) shows 21 contributions from Brazil, followed by Argentina (3), Costa Rica, and Mexico (2 each).…”

Ecotoxicological assessment of glyphosate‐based herbicides: Effects on different organisms

“…In agricultural fields, glyphosate is sprayed on plant foliage; however, some of the chemical could be deposited directly on the soil surface or carried by the wind to neighboring soils or leach after rainfall to neighboring water bodies, leading to exposure of nontarget terrestrial and aquatic organisms . In Brazil in 2011, approximately 340 million L of glyphosate were sprayed, which caused concern in relation to its possible nontarget effects, especially potential impacts on the health of humans and the ecosystem .…”