Non‐target effects of herbicides on soil nematode assemblages

Abstract

The decrease in predator abundance suggests that herbicide application disturbs soil food webs. The increase in bacterivore and decrease in fungivore abundance suggest that bacterivores are more tolerant and both fungivores and predators more sensitive to herbicide applications. Herbicides also have non-target effects on omnivores, which may be due to the increased amount of food resources for omnivores after weed control. Additionally, the use of herbicides may result in a risk of an increase in plant-parasitic nematode abundance.

A temporal assessment of nematode community structure and diversity in the rhizosphere of cisgenic Phytophthora infestans-resistant potatoes

“…However, the work correlates with results reported by Smith et al [49] who examined the impact of the Benomyl™ systemic fungicide on prairie tall grass and it also relates to the use of herbicide [27], which combined, reinforces the theory that the PR nematode group is highly sensitive to chemical disturbance. The only contradiction to this is the fact that the same response was not recorded with Sarpo Mira, suggesting that this cultivar can possibly counteract the negative impact on the PR group; possibly due to the extreme growth vigour of the cultivar, thereby presenting a larger biomass for the PR group to prey on [50].…”

“…Trophic group absolute value, without distinguishing between c–p, is another method with which to investigate nematode trophic structures [27, 47, 48]. Here no statistical difference was identified in quantitative values between the cisgenic Desiree and either its genetic comparator, cv.…”

“…In contrast, the weather conditions of 2014 and 2015 were more supportive of an enrichment condition, which can be linked with the reduction of PF (and increase of BF and OM). This would arise from the activation of soil biological processes, hence increasing food resources for the nematode populations [27]. …”

“…Widespread and highly diverse, nematodes form part of the food web of soil by occupying primary, secondary and tertiary positions in at least five trophic groups: bacterial feeding (BF), fungal feeding (FF), predators (PR), omnivorous (OM) and plant feeding (PF) [21], making them excellent indicators of fluctuations in soil composition arising from for example, plant genotype and/or type of soil management and environmental conditions in the rhizosphere. To date, multiple studies have been carried out using soil nematodes as indicators in different ecosystems evaluating for example the impact of crop management [22, 23], fertilizers [24], water availability [25], seasonal fluctuations [26] as well as the application of crop protectants [27]. From the perspective of monitoring nematode diversity in response to the cultivation of GM crops, several reports have detailed interactions in regards to GM maize, carrying Cry-type insecticidal proteins [28, 29].…”

Efeito de Herbicidas sobre a Biota de Invertebrados do Solo em Área de Restauração Florestal

“…Com isso, altera-se o funcionamento do solo (Cortet et al, 1999), como os processos de decomposição vegetal (Hendrix e Parmelee, 1985), a manutenção da estrutura do solo, a transformação e a mineralização da matéria orgânica e o controle de organismos considerados pragas (Gill e Garg, 2014). Há autores que concluem que há efeitos negativos do uso de herbicidas sobre a estruturação da comunidade de invertebrados do solo, como colêmbolos (Haque et al, 2011), nematoides (Zhao et al, 2013), minhocas (García-Pérez et al, 2014) e diversos grupos de microrganismos (Crouzet et al, 2010;Camelo et al, 2011;Karpouzas et al, 2014;Darine et al, 2015).…”