UMD Expert Urges Better Understanding of Farmer Pesticide Strategies to Address Impacts of Organic Farming.
Farm rows in California
Image Credit: David Silver, Creative Commons
When organic farms and conventional farms are located near one another, their farming practices can have implications for their neighbors. GMO pollen from conventional crops can drift to organic fields, and insects, fungi and weed seeds from organically farmed lands can drift to conventional fields.
University of Maryland Professor in the Department of Agricultural and Resource Economics, Erik Lichtenberg was recently asked by the journal Science to comment on a paper exploring this phenomenon in their March 22, 2024, issue.
The paper showed that conventional farmers in Kern County California used more pesticides when more organically managed fields were nearby. Meanwhile organic farmers, who use natural pesticides, apply less pesticide if more organic farms are nearby. The authors concluded that when organic farms are scattered across the landscape, overall pesticide use goes up. That’s because increases in pesticide use on conventional land outweigh reductions in use on organic farms.
The paper suggests that reducing pesticide requires something like zoning, with organic and conventional farms grouped into separated clusters. But Lichtenberg, who is an expert in the economics of pesticide regulation and pest management, cautions that, although the study was well done, the results should not be used to make dramatic decisions about where and how to locate organic and conventionally managed fields just yet.
Making decisions about how to address pesticide use in mixed farmlands based on this information is “akin to drawing inferences about the prevalence of disease by observing which medications were taken,” Lichtenberg said. “Such inferences are necessarily limited because the same medication can often be used to treat more than one disease.”
He noted that the study did not address how farmers select pest management strategies, why pesticide application strategies shifted with proximity to organic fields, which pests they are combating, or which crops they choose to grow.
“As organic farmland continues to expand, adverse interactions of the kind studied in this paper are likely to grow,” he said. “Effective action to minimize such spillovers requires a greater understanding of how they arise.”
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Lichtenberg’s article appears in Science Perspectives, Science, March 22, 2024.
