• Driving Near Recently Sprayed Fields Exposes People to Pesticides
  • Weeds Can Be Managed Without Chemical Pesticides
  • Learn to Manage Pests Naturally
  • Link to SK Organic Resources
  • Learn To Manage Weeds Without Chemical Pesticides
  • SNAP Display at Event
  • LIving Near Fields Increases Pesticide Exposure
  • Learn About Colony Collapse Disorder and How to Protect Bees
  • Learn About Pesticides in Foods
  • Grow a Lush Garden Organically

Soils - Pesticides in

also see pesticide drift/research and neonicotinoids, glyphosatefungicides,  water, digestive tract/microbiome, microbiota changes and wildlife/Terrestrial Invertebrates

Weed Killer Use Destroys Soil Life and Ecosystems, Paper Finds   (Beyond Pesticides, November 11, 2022) 'A paper published in Trends in Ecology & Evolution in late October sounds an unnerving alarm about the globally ubiquitous use of herbicides and the ecological destruction being caused. It asserts that widespread environmental contamination with these herbicide compounds is influencing soil, plant, and animal microbiomes in ways that are not only not well understood, but also, can have significant impacts on the functioning of organisms and their ecosystems — with evolutionary implications. '   'The study authors also note that adjuvant, “inert” ingredients in herbicide formulations can sometimes be even more toxic to non-target organisms than the active ingredients themselves,' In the US, these are untested for that effect and also secret. They are also secret in Canada but I am unsure if they have been tested for effects on non-target organisms. Likely not.   'The study identifies classes or modes of action for a host of herbicide active ingredients, including whether they act directly or indirectly on microbiota, and their respective effects on soil, plant, or animal microbiomes. Among the modes (and sample compounds) that have direct impacts on microbes are:

  • ACC (acetyl-CoA carboxylase) inhibitors (e.g., diclofop-methyl, haloxyfop)
  • ALS (acetolactate synthase) inhibitors (sulfonylureas, triazolopyrimidines)
  • EPSPS (5-enolpyruvylshikimate-3-phosphate synthase) inhibitors in the shikimate pathway (glyphosate)
  • glutamine synthetase inhibitors (glufosinate)The mechanisms that exhibit indirect impacts, including on cellular metabolism and hormone synthesis, are auxin-like herbicides (2,4-D, dicamba); photosystem (related to photosynthesis) inhibitors (triazines, paraquat, diphenyl ether); and gibberellin (plant hormone that stimulates stem elongation, germination, and flowering) inhibitors (acetochlor, metolachlor, pendimethalin).
  • The indirect impacts on microbiota include those that degrade bacterial diversity, erode microbial community structure, and disable nitrogen-fixing bacteria.'

Fungicide Use Harms Beneficial Soil Life, Jeopardizes Crop Yields  (Beyond Pesticides, October 25, 2022) 'Fungicide use harms soil and jeopardizes crop yields by reducing the prevalence of arbuscular mycorrhizal fungi (AMF), according to recent research published in Nature Ecology and Evolution. AMF are important fungi that form symbiotic relationships with plants in both natural and cropland soils, and their presence helps facilitate nutrient uptake, particularly for phosphorus. The natural grassland soils took up 64% more 33P (phosphorus, an essential crop nurient) than soils from the cropland sites. Analysis also finds that AMF richness and microbial biomass was lower in croplands soils by 41% and 29% respectively, with these soils having significantly more available P than in natural grassland soil.  Cropland soils that were not treated with a fungicide had an average P transfer 2.3 times greater than soils that had three fungicide applications over the last year in the study. In fact, P recovery rates decreased in tandem with the number of each additional fungicide application. Unsurprisingly, scientists found evidence for fungicides diminishing AMF richness, thereby reducing P uptake.' This experiment was done of the weed Plantago lanceolata because of its known ability to form associations with a range of different AMF species. Most domesticated crops grown today are not bred to have a symbiotic relationship with AMF. 

Plastic Coated Pesticides Adding to Soil and Ecosystem Contamination with Microplastics   (Beyond Pesticides, June 3, 2022) This article explains the role of plastics in climate change as well as the widespread contamination of everything wiht them. Agricultural uses of plastics go from synthetic mulches to coating pesticides and fertilizers, purportedly to allow for controlled release of chemicals or nutrients. '...agriculture is one of the largest users of products with intentionally added microplastics, and that this use is rising (11% growth is projected for 2018 to 2025). Microplastics remain in the soil long after the encapsulation’s function — slow release — ends, polluting the soil and readily dispersing into the air or water.' These coatings are greenwashed as “planet-safe” choices. The marketing 'involves no mention of “plastics,” but instead, use of less well-known and poorly understood terms, such as “polymer,” in describing the coating material. Further, “plastic encapsulation may be portrayed as a plus for the environment.' SNAP Comment: although not technically a pesticide, I have linked this to this page. As plastics are well known for adsorbing all kinds of toxins, miroplastics may increase the half-life of applied pesticides. 

Glyphosate Kills Microorganisms Beneficial to Plants, Animals, and Humans   (Beyond Pesticides, October 28, 2021) A study published in Frontiers in Environmental Science finds the popular herbicide glyphosate negatively affects microbial communities, indirectly influencing plant, animal, and human health. Exposure to sublethal concentrations of glyphosate shifts microbial community composition, destroying beneficial microorganisms while preserving pathogenic organisms. 

Monoculture Agriculture Leads to Poor Soil Health     (Beyond Pesticides, October 6, 2021) 'Agricultural soils under monoculture cropping systems are not as healthy as soils with diverse plantings, finds research recently published in the journal Agrosystems, Geosciences and Environment. Soil and soil quality are declining rapidly in the United States and around the world, with recent data indicating that the U.S. Corn Belt has lost 35% of its topsoil.' The research compared a soy,/corn monocultures to perennial grass.   'The study notes these perennial systems have much more microbial diversity, over eight times more mycorrhizal fungi, and higher ratios of fungi to bacteria.     The higher ratio of fungi to bacteria is likely indicative of the frequency of plowing in the monoculture systems, which occurred each year after harvest, according to the study. Repeated tillage breaks fungal connections that help stabilize soil, which can lead to worsening soil structure.    Prior studies that utilize the long-term cropping systems studied in the current paper indicated the regular use of 28% urea-ammonium nitrate fertilizer, glyphosateglufosinate, and atrazine have a strong propensity to harm soil health.'

Vital soil organisms being harmed by pesticides, study shows    The tiny creatures are the ‘unsung heroes’ that keep soils healthy and underpin all life on land (The Guardian, 4 May 2021)    'The researchers found the measured impacts of farm chemicals on earthworms, beetles, springtails and other organisms were overwhelmingly negative. Other scientists said the findings were alarming, given the importance of these “unsung heroes”.' The study 'covered more than 275 species and 284 pesticides, but excluded any chemicals currently banned in the US.    Donley said: “It’s not just one or two pesticides that are causing harm, the results are really very consistent across the whole class of chemical poisons.” A 2012 review showed that pesticides can also harm microbial life in soils.'

Toxic Pesticides Are Polluting Over Half of Arable Land, Reinforcing Need for Global Organic Transition   (Beyond Pesticides, April 7, 2021) 'Toxic pesticides are putting more than half of the Earth’s farmland at risk of pesticide pollution that contaminates water, harms biodiversity, and ultimately undermines food security, according to research published in Nature Geosciences last month.   A pesticide was deemed to put a location at risk if the predicted environmental concentration of the pesticide was expected to be above the no-effect concentration for ecotoxicological harm. The high risk designation was noted when expected environmental concentrations were more than three orders of magnitude (1,000x) higher than the no-effect concentration.     Scientists determined that 75% of global agricultural land was at risk, with 31% at high risk. Considering the additive effects of pesticide use, researchers found that 64% of ag land was at risk from more than one of the 92 pesticide active ingredients evaluated. Shockingly, 21% of farmland is at risk by more than 10 pesticides.'

Pesticides Are More Widespread in Both Conventional and Organic Agricultural Soils than Previously Thought    (Beyond Pesticides, April 1, 2021) 'A legacy of toxic pesticide use in agriculture is showing up as residues on organic farms, emphasizing the threat of a history of weak regulatory standards that has left farmland poisoned and the urgent need to transition to organic. A study, published in Environmental Science & Technologydocuments the findings of pesticide residues on organic farmland and shows a decrease in residues after transition, with lingering effects for decades.' Researchers studied residues of 46 current pesticides. Conventional soils had 9 times higher pesticide contamination and the longer land was organic, the lower the residue. These pesticide residues affect soil organisms and consequently soil processes and functions. More studies are needed. 

Implications for Human Health: Glyphosate-Related Soil Erosion Re-Releases Toxic Pesticides from Soil   French West Indies study.  (Beyond Pesticides, March 4, 2021) A new study finds glyphosate use stimulates soil erosion responsible for releasing banned, toxic pesticide chlordecone (Kepone), which was used in banana production. ... Researchers note, “Chlordecone fluxes drastically increased when glyphosate use began, leading to widespread ecosystem contamination. As glyphosate is used globally, ecotoxicological risk management strategies should consider how its application affects persistent pesticide storage in soils, transfer dynamics, and widespread contamination.” Conventional pesticide use contaminates soil and their respective Critical Zone (CZ) compartments.  SNAP Comment: I wonder how many other chemicals it might release through erosion... However, there was a lot more soil drifting in SK before chem fallowing with Roundup.

Study Finds that Regenerative Agriculture Is Undermined by Toxic Pesticide Use   (Beyond Pesticides, September 18, 2019) A new report published by Friends of the Earth (FOE), “Pesticides and Soil Health” highlights healthy soil as a key pillar of regenerative, organic agriculture. FOE focuses in on an often-overlooked aspect to soil health, “that eliminating or greatly reducing toxic pesticides is key to building healthy soils and ecosystems for a healthy planet.”   'Toxic chemicals damage the soil microbiota by decreasing soil microbial biomass and altering the composition of the soil microbiome. Fungi-rich soil improves productivity and increases carbon sequestration capacity, but use of pesticides results in a bacteria-dominant ecosystem. Changes in soil composition also result in “vacant ecological niches, so organisms that were rare become abundant and vice versa.” This unhealthy and imbalanced soil has reduced fertility and resilience, and plants grown in such conditions are more vulnerable to parasites and pathogens.  This degraded soil sequesters less carbon than soil with a diverse array of microbiota.

Neonicotinoid Insecticides: Environmental Occurrence in Soil, Water and Atmospheric Particles  (Chapter 2 of Pesticides book, Avid Science. Renata Raina-Fulton, July 30, 2016) 
'they can partition into the particle phase in the atmosphere or be lost during or subsequent to seeding from soil dust created from planters. Presence of neonicotinoid containing particles in the atmosphere is of concern for direct exposure to bees as well as movement
in the environment such as subsequent deposition into surface waters. Concentrations of neonicotinoids in water, soil and atmospheric particles will be discussed'

New evidence of pesticides in Calgary air, soil  (Bridget Brown, CTV Calgary,  June 10, 2015)   'An environmental testing facility has found pesticides that are expected to dissipate in a matter of days persisting in Calgary’s soil and air for months after lawn and garden season has ended.2,4 D is supposed to have a half-life in the order of two weeks,” he says, “and the last application of 2,4D would be the previous fall. and yet in April, we find it.”'  The team also found  atrazine and Dicamba. 'The amount of Dicamba exceeded provincially regulated safe levels.'    SNAP COMMENT: I hope the lab is still in business and the scientist still employed!

Pesticides found in more than 80% of tested European soils   (PhysOrg,January 18, 2019, CORDIS)    'Pesticide residues were found in 83% of the analysed agricultural soils in 166 different pesticide combinations. The most common mixtures detected at the highest concentrations were the controversial weedkiller glyphosate and its metabolite aminomethylphosphonic acid, followed by the commonly used pesticide dichlorodiphenyltrichloroethane (banned in the EU in 1986), and the broad-spectrum fungicides boscalidepoxiconazole and tebuconazole'  'We are increasingly seeing the negative side of chemically intensive system of food production. Today, 2,000 pesticides with 500 chemical substances are being used in Europe. However, data on how such substances affect soil quality is incomplete and fragmented, and fails to clearly reflect their overall impact on soil systems and human health.'

Multiple Pesticide Residues in Soil Raise Alarm (Beyond Pesticides, November 30, 2018)   A pan-European study. 'A study published this month in Science of the Total Environmenreveals numerous pesticide residues persisting in soil, harming the viability of agricultural lands and increasing risk of off-site contamination...Samples were then analyzed for the concentration of 76 pesticide residues. These 76 pesticides were selected as being most often applied on conventional crops. Eighty-three percent of samples contained varying degrees of pesticide residues, with 25 percent showing one pesticide residue and 58 percent showing mixtures of two or more. Only 17 percent of the tested soils had no pesticide residues detected. More residues detected inhe northern, eastern and western EU regions. Glyphosate was the most widely detected.'  SNAP comment: If anone bothered to look t agricultural soils n Saskatchewan or Canada, widespread soil contamination would be found too. We already know glyphosate and is by-product AMPA persist in our northern soils.