For the past year, Colten Catterton, a Green Cover Seed Representative and Northwest Missouri State University graduate student has researched cover crops. The Harwood, Md., native researched these crops at the university's plot just outside the Center for Innovation and Entrepreneurship.
The plot, which has been a community garden, dairy pasture, and sweet corn field, spent the last year planted in cover ranging from a variety of monocultures – groups of grasses like rye, triticale and oats, a section of brassicas with rapeseed, radish and mustard, and legumes like hairy vetch, cowpeas and clovers. It also included diverse mixtures based on accomplishing the overall goal.
Benefits of cover for a conventional farmer
Last fall, the plot now in corn was planted with a mixture of BMR grazing corn, sorghum sudangrass, and cowpeas. Any cover that wintered over was terminated before planting corn to see the effects of cover on corn. After his experience with multiple cover crops, including writing his thesis on using cover crops as forage, Catterton says diversity always wins. "The plants work together, they don't work against each other," he explains. "Research shows by mixing species together you can increase water-use efficiency and biomass production. You're achieving multiple goals at one time."
The benefit for corn is apparent on one plot, where rich, dark green corn previously had daikon oilseed radish, also known as nitro radish. In addition to the benefits of breaking up soil compaction, the radish pulls up nutrients like nitrogen, phosphorus, calcium and sulfur. "Radish is a good hyper accumulator of nutrients," Catterton notes. "It releases it back readily in the spring due to quick decomposition. This decomposition renders it in an available form back in the soil so the corn is able to utilize it." It winter kills with several nights in the mid-teens, starting decomposition. It gives off a potent scent when the weather warms up and it biofumigates the soil.
It has also helped with weed control. "The radish showed incredible weed suppression of small seeded weeds," Catterton says. "It probably suppressed the weeds another month to a month and a half." These are some reasons it has been called the "training wheel" of cover crops. "It's pretty hard to find a flaw with radish," he says. "You can put it in just about any mixture – other than spring mixtures, because it will just want to bolt and produce seed."
For a look at how bioenergy crops faired in the plots click here.