Cover crops have numerous benefits, which we’ve discussed at length in this blog—everything from improving soil health, increasing water infiltration, suppressing weeds, and more. One under-utilized benefit of covers is how cover crops can be used for pest management.
I interviewed Justin McMechan, assistant professor for crop protection and cropping systems at University of Nebraska Extension, about using cover crops as part of an integrated pest management plan. Here are some key takeaways from our discussion:
- An integrated pest management plan applies not just to insects, but also plant diseases and weeds.
- Current research is studying the role of cover crops and how they influence insect populations, especially arthropods (such as spiders and centipedes). Cover crop termination timing, cash crops planted, and cover crop species all factor into an integrated pest management plan.
- A study from South Dakota found rootworms in slender wheat grass are one example of an insect species that were documented to have decreased pest pressure. Having beneficial insects in the cover crop system has also indirectly been effective in reducing destructive insects.
- Growing seasons and the timing of planting influence which cover crop species are planted in various geographic areas. However, cereal rye is a common species of cover crop, and the timing of its planting impacts the amount of biomass that results in the spring. And the amount of biomass dictates what insects are present in that system. Other states are studying crimson clover and how it works with insects in cover cropping systems.
- Most research currently available focuses on above-ground pests, such as black cutworm and armyworms, which are attracted to dense vegetation, including cover crops, in the spring.
McMechan acknowledges that there is a lot of research still to be done in this area, and that more research will help growers fine-tune their approach to using cover crops as a means of pest control.
