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Organic farming helps biodiversity, pest control

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Organic farming helps biodiversity, pest control
A team of
researchers from Washington State University and the University of Georgia have
found that organic farming increases biodiversity among beneficial,
pest-killing predators and pathogens.

July 7, 2010 – A team of
researchers from Washington State University and the University of Georgia has
found that organic farming increases biodiversity among beneficial,
pest-killing predators and pathogens.

In potato crops, this led
to fewer insect pests and larger potato plants.

“It’s always been a
mystery how organic farmers get high yields without using synthetic
insecticides,” says co-author Bill Snyder, associate professor of entomology at
Washington State University. “Our study suggests that biodiversity conservation
may be a key to their success.”

Ecosystems with more total
species, and more beneficial species that are relatively evenly distributed,
are thought to be healthiest. The use of insecticides can harm biodiversity by
reducing the number of species and by making some species (often pests) much
more common than others. The study, which was funded by USDA’s National
Institute of Food and Agriculture (NIFA) and published in the July 1 edition of
the journal Nature, shows that organic farming practices lead to many equally
common beneficial species, and that this reduces pest problems.

In potato fields that used
conventional control practices (e.g., applications of broad-acting
insecticides), usually just one species of beneficial predatory insect or
pest-killing pathogen was common. In contrast, in organic fields several
beneficial species were about equally common. Experiments showed that groups of
evenly abundant beneficial species, typical of organic farms, were far more
effective at killing potato beetle pests. Because natural enemies are usually
more even in organic crops of many different kinds, not just potato, these
benefits could be widespread.

NIFA funded this project
through the National Research Initiative Arthropod and Nematode Biology and
Management competitive grants program.