Study links farmer beliefs and soil practices to stronger natural pest protection
The soil microbiome plays an important role in supporting ecosystems, crop health, and natural pest control. However, it has not always been clear which farming practices best support beneficial soil microbes or why farmers choose certain methods.
A recent study conducted at the University of Illinois Urbana-Champaign and Cornell University examined these questions by analyzing surveys and soil samples from 85 organic farmers in New York. Researchers studied how farmer beliefs influence management practices and how those practices affect soil microbes and plant defense.
“Our goal was to build a socio-ecological model that looks at how farmer beliefs about the soil microbiome mediate their management practices, and how those practices in turn affect ecological responses,” said lead author Elias Bloom, postdoctoral research associate at Cornell.
Scientists used DNA sequencing to identify microbes in soil samples. They also tested pest resistance by growing pea plants in soil mixed with microbiome extracts and introducing aphids under controlled laboratory conditions.
The study identified three farming practices that consistently improved the soil microbiome and strengthened plants’ natural defenses against pests. These practices were no tillage or minimal soil disturbance, the use of cover crops such as grasses grown in different seasons, and targeted watering methods like drip irrigation or hand watering.
In contrast, the use of insecticides and pesticides within the previous three years reduced beneficial microbiome activity and weakened plant defenses. Compost use produced mixed results, depending on the original soil conditions.
The research also showed that farmer beliefs strongly influenced which practices were adopted. In many cases, beliefs about soil health and microbes mattered more than economic considerations.
“It is important to keep in mind that pest suppression is just one function of the microbiome. There are still many unknown functions, and we don’t know which of these will be needed in the future as challenges in agriculture continue to arise, so it’s important to conserve microbial diversity,” said co-author on the study, Clare Casteel.
Researchers are now studying how providing farmers with microbiome information and cost-share options may increase the adoption of conservation practices. These findings highlight the importance of education and extension efforts to promote sustainable soil management.
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