HAMILTON, Ohio — When Jim Hoorman mentioned “home-grown nitrogen,” most of the farmers sat up a little straighter at the Butler County Soil and Water Conservation District Cover Crop Field Day. 

With fertilizer costs continuing to squeeze profit, Dave Brandt of the Soil Health Academy, also got their attention when he said eliminating some tillage by incorporating cover crops could reduce inputs by as much as 60 percent.

Attendee Stephan Janos said cover crops helped the highly erodible clay soils that he farmed. Even though they take a little more time, he wondered why farmers were reluctant to try them.

Legumes and clovers are both nitrogen-producing plants. By using them as cover crops after the main crop has grown, they’ll produce nitrogen which the next crop can use, said Hoorman of Hoorman Soil Health Services.

“Usually, we plant them after wheat which would give us enough time, but they can also be planted after early maturing soybeans,” Hoorman said. “This time of year, we’d be planting Austrian winter peas, and they can give up to about 150 pounds of nitrogen (to the acre). Next year we would plant corn into that.”

The nitrogen is in the stem and then the leaves of the cover crop, he said. When producers terminate the cover crop, it’s like a slow release of nitrogen fertilizer to the corn roots. The rain will wash the nitrogen into the soil right around the roots, and those roots can take it up and use it for corn production.

Farmers can use an herbicide to kill the cover crop and any other weeds, and then plant the corn into the residue. Organic farmers or those who are interested in soil health can use a crimper-roller. The cover crop will die soon and provide mulch on the soil.

“It’s a nice environment for a lot of the beneficial insects that are in the soil,” Hoorman said. “That’s why a lot of people are starting to look at how to use the crimper-roller to create this favorable environment.”

When using a cover crop, it is important to inoculate the soil with the right inoculant, he added. 

Brandt said that before planting corn, he likes to use a mix of two or three legumes with two grasses and maybe two broadleaf plants. Before planting soybeans, Brandt prefers more grasses, such as rye, barley, or triticale.

“With those, we will capture any nutrients that were left after the corn crop that will go to soybeans,” Brandt said. “That will build a fibrous root system, will increase water infiltration, and the ability for those roots to break down unavailable phosphorous and potash in the soil. That makes it more available so we can reduce the use of fertilization by quite a lot by using those grasses to go to soybeans.” 

A Fennig Equipment representative also talked about effective cover crop inter-seeding. Bob Hendershot, grazing specialist, talked about grazing cover crops and the many benefits they provide to livestock.