“For example, glyphosate, used widely to curb grass growth between vine rows since the 1990s, was detected, through its metabolite, in a sediment sample over the last 20 years. Further, this herbicide-induced erosion has re-mobilized DDT and its metabolites – banned in 1972 but lingering in the vineyard soil – into the lake.”
The researchers reasoned that erosion was occurring because of the permanently bare soil conditions created by frequent herbicide spraying. “The soils underwent a change in storage conditions, converting from sinks to sources of pesticides,” the study asserts.
The discovery of this new externality associated with conventional farming strengthens calls from proponents of organic agriculture to replace toxic chemicals with practices that work with nature and build natural pest resiliency from the soil up. Included within the Organic Foods Production Act is the requirement that organic farming systems “contain provisions designed to foster soil fertility, primarily through the management of the organic content of the soil through proper tillage, crop rotation, and manuring.” Previous studies have shown that instituting organic practices does create healthier soils than conventional techniques. A paper published in 2010 found that organic strawberry farming resulted in both healthier soils and higher quality fruit. Research from the U.S. Department of Agriculture’s Agricultural Research Service determined that organic farming builds soil organic matter better than no-till conventional techniques that rely on chemical herbicide inputs.
As organic agriculture continues to grow, it is important that consumers become active in defending the integrity of organic production, so that harmful practices which undermine healthy soil are never instituted. Take action for strong organic standards by visiting Beyond Pesticides Save Our Organic program page. And learn more about the importance of organic agriculture through our program page.
Source: PNAS, environmentalresearchweb.org