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Full house for local cover crop field day: Sign of the times?

09/17/2013 @ 4:25pm

Farmers filled up a farm shop in eastern Iowa on September 10 to hear more about using cover crops in corn and soybean rotations. The hot, dry and windy weather forced cancellation of a planned aerial seeding demonstration at the Jim Meade farm in Johnson County, but high interest in the practice was clear.

One of Meade’s fields, which visitors could view from the shop, consists of several soil types that range from 9% to 18% slopes. The field already includes a buffer strip and wide grass waterways, and Meade uses minimum tillage. But he’s still not happy with the soil erosion brought about by volatile weather in recent years. He’s interested in cover crops for further erosion control as well as a means to boost soil organic matter.

Other Iowa and Midwest farmers have shown increased interest in cover crops this year, including for management of stands on prevented planting acres. In a Successful Farming magazine reader survey early this year, 28% of farmers said they were now using cover crops, and another 38% said they expected to plant them in the future.  

Jim Fawcett, an Iowa State Extension specialist, kicked off the Johnson County, Iowa, session touting the value of cover crops in helping reach the state's voluntary program for reducing nutrient losses. Cover crops can cut nitrate–N losses by about 30%, a big step in reaching conservation goals, he said.

Two farmers experienced with cover crop use headlined the event and drew good interaction from attendees, which included agency representatives, seed dealers, and aerial applicators. Questions from farmers centered on the agronomic details of managing cover crops -- species selection, seeding methods and timing, spring management, and more.

Steve Berger (photo, above), an eastern Iowa farmer with 10 years of experience in using cover crops in no-till, said there are three keys to success with the system: getting the planter set up properly, being ready to use insecticides, and applying nitrogen in a timely fashion.

“The most important thing is learning how to manage your nitrogen, because the increased microbes [with cover crops] that reduce the residue out there are also going to take nitrogen and compete with the corn,” Berger said. “So managing that nitrogen, getting more nitrogen put on with the corn planter, and sidedressing, is key. It’s not about using more nitrogen, but getting timely applications.”

Yields, he said, are “holding their own and steadily increasing."

Berger plants mainly cereal rye, typically at a rate of 1 bu/ac, but has sometimes upped it to 2 bu/ac, often drilled in right behind the planter, but at times as late as the first of December. Because he already owned a drill, the application cost is about the same as aerial seeding, he says. 

He buys seed by the semi-load and stores it in bulk bins. Around April 1, he applies glyphosate to kill the rye. “I’ve never had a problem killing cereal rye," he said

He's evolving to use of multiple species of cover crops, with oats being “the next obvious choice.”

Berger sees cover crops as a long-term investment, but one that will pay off in soil erosion control and increased organic matter. “Our organic matter is going up by about .10% a year,” he said.

Rob Stout, another eastern Iowa farmer on the program, drills winter rye for his cover crops, too, but also has experimented with aerial seeding and other cover crops, including oats, tillage radish and crimson clover.

Like Berger, Stout is keen on his results with cover crops and is tracking soil organic matter levels. He touted the value of residue managers on the planter, mentioning good success with Yetter and Martin row cleaners.

For getting started with cover crops, Berger told farmers first to plant cereal rye ahead of soybeans. “Go out and have it either aerial applied or drilled into cornstalks,” he said. “Beans are more forgiving, they’re not as stand sensitive to yield. You’ll have more time to kill that rye. You have more time to see that rye grow and get some confidence. Then you can move into growing corn, which takes some more management.” 

Recent reports from Successful Farming on cover crops:

13 questions and answers about cover crops

Cover crops spur slacker soils