Pesticides encompass herbicides, insecticides and fungicides. They’re chemical compounds designed to kill, each with its own targets and modes of action. As little as 0.1 percent of an applied pesticide interacts with its targeted weed or pest. The remainder contaminates the soil, air, and water and can cause significant collateral damage throughout the ecosystem. Pesticides can undercut regenerative agriculture goals by harming soil communities and altering critical biochemical processes in the soil. By disrupting soil communities, pesticides can cause significant changes in the composition, diversity, and basic functioning of important soil microflora.
The United States uses more than 1 billion pounds of pesticides every year. Pesticides can also linger in the soil for years or decades after they are applied, continuing to harm soil health.
Thus, soil organisms encounter a cocktail of toxic chemicals. Research shows that mixtures of pesticide residues in the soil are the rule, not the exception since farmers typically use multiple pesticides. For example, the U.S. Department of Agriculture estimates that Washington apples are treated with an average of 51 different pesticides in 6 to 17 applications per year. This continuous use of pesticides doesn’t give soil communities time to recover.
While it makes sense that pesticide use will eventually impact soil biology, it might not be so clear that they can reduce photosynthesis, the plant’s engine for energy production that also supports mineralization of soil nutrients via exudation of sugars to the soil microbiology. Pesticide application causes oxidative stress, or the degradation of chlorophyll pigments and proteins, ultimately causing a reduction in the photosynthetic efficiency of plants. It is also important to note that plants under stress (i.e., excess heat) may be extra vulnerable to phytotoxicity.
This is a big deal because the overall impact is a loss of production and growing days, and that leads to a decrease in yields and greater risk exposure.
Pesticides kill or harm soil invertebrates that provide essential ecosystem benefits like cycling nutrients that plants need to grow, decomposing dead plants and animals so they can nourish new life, and mitigating pests and diseases. The key point is that pesticides create or promote imbalances, through the destruction of biodiversity, resulting in the rise to dominance of other, nontarget pests or pathogens. Some organisms can be suppressed, but others may proliferate in the resulting vacant ecological niches, so organisms that were rare become abundant and vice versa.
Research also shows that pesticides can impact larger fauna that helps maintain the structure and fertility of the soil, and they can affect the balance between bacterial and fungal populations in the soil which is important for optimizing carbon sequestration. Good soil biodiversity also reduces the impacts of extreme droughts and floods, which are becoming more common as the climate changes.
The negative effects of pesticides are not limited to the area of application. Runoff and airborne drift can carry pesticides into distant aquatic environments or other fields, grazing areas, human settlements, and undeveloped areas.
While pesticide companies claim their products are needed to feed the world’s growing population, there is more and more data pointing in the opposite direction: that sustainable food production is the preferred long-term approach.
There are other alternatives to the use of these heavy chemistries, which include the use of bio-pesticides.
Andaman Ag, of course, remains at the forefront of biological products. We have organic biocontrols including a citrus acid-based fungicide called FungOUT and a cinnamon-based insecticide/miticide called CinnAcar. Both products have been tried and tested for years, are sold worldwide, and offer growers a viable alternative to harming our soils and reducing photosynthesis production in our crops. We’re in it for the long run.
