Short-duration cover crops

Unlike traditional field crops like corn and soybeans, vegetable growers have the advantage of growing vegetables in different seasons with different maturity dates. This provides the flexibility to incorporate short-duration cover crops throughout the growing season.

Ajay Nair is an extension vegetable production specialist at Iowa State University. He says short season cover crops include oilseed radish, yellow mustard, cowpea, and buckwheat. From seeding to flowering, they only take 50-to-60 days.

"Let’s say a vegetable grower had lettuce in the spring, planted outside in the field around mid-April, that crop would be done by about the end of May. So then there’s a time of about two months, which is like June and July, before they plant their fall vegetable," says Nair. "If a grower is growing a spring vegetable and then followed by a fall vegetable, these two months in the middle can be utilized to put in a short-duration cover crop."

Adding cover crops in your rotation will provide specific advantages depending on their physiology, shape, size, and growth habit. This includes weed suppression, soil and water conservation and holding on to nitrogen.

"If I have a cover crop, that cover crop can take up that nitrogen and hold onto it, so it’s kind of a bridge," he says. "You prevent the leaching of the nitrogen and you also get that nitrogen that now can be utilized by the fall crop. And in addition to that, like with buckwheat, they attract pollinators, they attract beneficial insects. So, it’s a habitat for those insects as well."

When it’s time to plant the fall crop, he says you can till the cover crop under and then plant the vegetables. Or, you can roll it down and use it as a mulch to suppress weeds and do strip-till or no-till.