Persistent Herbicides and Composting

Herbicides are liquid or solid products used by homeowners, farmers, ranchers, and more to combat weeds. While herbicides have detailed labels that list all appropriate uses, warnings, and restrictions, there are still a number of ways that they can wind up in products intended for composting. Continue reading to learn what persistent herbicides are and how they can impact composting. Contact A1 Organics or visit us at one of our locations in Commerce City, Keenesburg, Sheridan, or Eaton for more information.

Herbicides in Compost

Trying to stay on top of the types of herbicides on the market is nearly impossible since there are thousands of retail herbicide products produced by a wide number of companies. Additionally, these companies continue to manufacture new herbicide products as they look for ways to overcome plant resistance to specific ingredients or to specifically target a specific group of plants. The chemical industry also continues to research new herbicides that are less toxic to water, soil, wildlife, and humans.

There are a number of studies that have shown that most herbicides rapidly degrade during the composting process. This degradation process is measured in half-life since this is the amount of time required to reduce the concentration of the herbicide by half. The time frame for herbicides during the composting process can range from one day to two years, and the concentration is reduced by one or more of the following pathways:

• Decomposition by microbes
• Chemical decomposition
• Volatilization into a gas
• Decomposition by sunlight
• Plant uptake and metabolism
• Leaching into soil
• Surface runoff

Persistent herbicides are long-lasting because many of the traditional decomposition pathways that are effective in breaking down other herbicides are either ineffective or too slow.

Persistent Herbicides

When vegetation that was treated with a persistent herbicide is then composted at a facility, the results may be a finished product that has concentrations of the herbicide that can then negatively affect certain sensitive plants. The irony is that the environmental benefits of persistent herbicides — relatively low toxicity and plant family-specific action — are the source of the problem when it comes to composting.

The active ingredients in persistent herbicides are designed to mimic natural plant auxins, which are the growth hormones that control plant cell growth. Persistent herbicides disrupt plant growth by binding to the auxin receptor sites, which in turn makes the site unavailable for the plant-produced biological auxin. By blocking the auxin, the persistent herbicide is able to stop the growth of the weed. In order for a compost facility to prevent or mitigate persistent herbicide contamination in a composted product, there are a number of details that must be understood and evaluated, including why and how they were used, where they were used, and much more.

Composting Denver

At A1 Organics, we are committed to providing our customers with the highest-quality composting products available. We offer four locations along the Front Range for your convenience in Commerce City, Keenesburg, Sheridan, and Eaton. Contact us today to purchase composting, soil, or to schedule organic recycling services.