Cover crop promoter
Over the past five years, Wenning has served on the Decatur County SWCD Board of Supervisors. He’s become a goodwill ambassador for cover crops and no-till farming in the county, hosting numerous field days and soil-health training sessions.
“Through his leadership, the Decatur County SWCD has been put on the map as a forerunner in the region and the state,” says Michael Hughes, NRCS district conservationist in Decatur County. “Wenning Farms has hosted more than 10 soil-health-related field days over the previous five years. The field days include two NRCS training sessions and a FSA district tour in 2007. Roger also serves locally by mentoring and advising new adopters of soil health practices.”
For Wenning, such leadership just goes with the territory. “I felt that some of my duties were to help inform people, so I planted cover crops in small plots,” he says. “This was something I could do, not only to help me learn, but also help the neighbors and anyone else interested in soil health. Then we started holding field days, digging soil pits and checking roots to see how these cover crops worked. We’ve had as many as 15 species of cover crops planted in small plots, as well as mixes.”
He’s planted many varieties of ryegrass to see which ones overwinter the best. Ryegrass is one of Wenning’s favorite cover-crop species. “It has a strong root system that will go deeper into my hard clay soils. We often find ryegrass roots over 6 ft. deep in soil pits.”
He’s now evaluating ryegrass in mixtures with species such as crimson clover and oilseed radish. “Crimson clover has a little different root system that helps to break up the soil,” he says. “It also feeds the ryegrass some nitrogen throughout the winter and corn nitrogen the following year.”
He’s also experimented with radishes’ soil-building properties. “On the ground I own, I have used cover crops long enough that I don’t use very many radishes. I think they are good in a mix to help break up a hardpan, but you need ryegrass to get the roots started through it. Then the radish roots will follow.”
Building soil health is as much art as it is science. “It definitely requires a systems approach,” Wenning points out. “It’s not just no-till or cover crops that gets it done. There is a whole list of things we have to do right to get the soil healthy. We still have a long way to go, but we are definitely seeing improved yields. I don’t have the best dirt to start with, but I’m making it better.”
The value of healthy soils was driven home when Wenning rented a farm about 30 miles from farm headquarters. “Now that we are getting our soil health right, our farm has typically averaged better than 200-bushel corn. The same soil type on the farm we rented only produces two-thirds as much. This really showed me what soil health is worth.”
Wenning puts a lot of effort into tracking the impact of management changes on yields. “We are always evaluating the things in the field,” he says. “We do fungicide checks, we look at population and nitrogen rates on corn. I set a flag when we change soybean varieties.
“I yield check just about everything we do in order to see what works best,” Wenning says.