Only recently have large numbers of no-tillers discovered the value of cover crops to aid their soil and cash crops. Many no-tillers are still learning how and when to burn down the cover crops to prevent competition with their corn, soybeans, etc.
But researchers with the USDA’s Agricultural Research Service and Iowa State University are now studying what they call “living mulch” — cover crops that are not totally controlled when cash crops are seeded into them.
Like cover crops, living mulches help improve soil quality and stave off weeds and erosion, according to the researchers. But living mulches might offer the additional benefit of providing habitat for beneficial predators that feed on destructive insects.
The scientists’ 2-year study shows that predators killed many more pupae of the European corn borer in fields with living mulches than in mulch-free plots.
The study used alfalfa and kura clover for mulches. Researchers found increases in the number of predators and in the number of pupae the predators ate in a rotation of corn, soybeans and forage crops. The predators were mostly carabid ground beetles and spiders.
In the living mulches, predatory insects killed 66 percent of the borer pupae planted in corn, a 51 percent increase over non-mulched control plots, and 65 percent of the pupae in soybeans, 13 percent more than in the control plots.
The scientists are conducting similar studies targeting other insect pests.
The study found that living mulches alone might not offer sufficient pest suppression, and the mulches…