Jack Boyer has been working with cover crops longer than most Iowa farmers. The Reinbeck farmer started planting cover crops about five years ago as a way to build organic matter in his fields, stem erosion and trim nutrient loss. And this fall, for the first time, all of his fields were aerially-seeded with cover crops prior to harvest.
Still, the Black Hawk County Farm Bureau member and retired John Deere engineer is the first to say he’s still tinkering, experimenting and trying to find better ways to raise cover crops.
"Farming is always a learning process, and cover crops are the same," said Boyer.
The same kind of experimentation and tinkering on cover crops is happening all over Iowa, as farmers continue to work to find ways integrate the new practice into their cropping routines.
Many are having the cover crops seeds spread by planes into standing crops. Others are buying or retrofitting high-clearance ground rigs that can roll through unharvested cornfields and drop cover crop seeds between the rows.
And many, like Boyer, are experimenting with planting cover crops very early, well before the corn has reached the tassel stage. The idea behind the early planting is to provide cover crop seed time to germinate and establish a root system before the corn plants grow tall enough to create a canopy that restricts sunlight.
Flexibility and innovation
That kind of experimentation and flexibility on cover crops and other conservation practices is really a hallmark of the Iowa Nutrient Reduction Strategy, said Iowa Agriculture Secretary Bill Northey.
"We want people to try different things to see what works on their own farms to reach our nutrient reduction goals," he said. "Every farm is going to be different, and every year could be different, so you need that flexibility."
Cover crops are a pillar of the nutrient reduction strategy, which was launched in 2013 by the Iowa Department of Agriculture and Land Stewardship and the Iowa Department of Natural Resources with technical support from Iowa State University (ISU). The pace-setting plan is designed to improve surface water quality in Iowa rivers, streams and lakes.
Research by ISU and other institutions has consistently shown that cover crops can reduce nitrogen loss by 30 percent and phosphorus loss by nearly that much, while protecting against soil erosion. Cover crops are also a very important part of the water quality initiative because they can be planted in all types of terrain and can help reduce nitrogen loss in the early spring, when Iowa’s wet soils are often most vulnerable, Northey said.
In addition, Boyer and many other farmers say that along with the water quality benefits, cover crops help build the quality of the soil, which will ultimately pay off in improved yields. "I absolutely believe that cover crops are helping my soil quality. It’s really like night and day where they are planted," Boyer said.
But getting cover crops established before the end of Iowa’s growing season often presents a problem for farmers. It’s especially difficult in the northern half of the state, where the growing season is typically over when the corn harvest is complete.
That’s why farmers like Boyer and Loran Steinlage, another cover crop veteran, are experimenting with early seeding.
"You’ve just got to get it established early. We just don’t have a fall up here anymore, it seems," said Steinlage, who farms near West Union in Fayette County.
While it’s still in the early experimental phase, early seeding of cover crops is getting a lot of attention, said Chad Ingels, ISU watershed project coordinator.
"There is certainly a lot of talk about trying to find ways to plant cover crops early at the field days I’ve been attending this summer," he said. "I think we hear about some people trying it, and I think there are a lot of guys trying things on their own and not talking a lot about it."
It’s all part of the overall excitement about cover crops, Ingels said. "Farmers are just looking for ways to make them work better," he said.
Early cover crop seeding can save money because the cover crop seeds are planted in June, along with the final side-dress application of fertilizer, Steinlage said.
"You don’t have to hire an airplane or a ground rig, so there is a savings there," he said.
Steinlage said the early planting of cover crops has worked well and the seeds have established a good root system. "It looks like I’ll have a nice green mat to roll on at harvest time," he said.
Others, like Boyer, are still working to determine the optimum planting time to get the cover crop seeds established before they are shaded out by corn leaves.
"It’s always a learning process, and with my engineering background, that use of experimenting and data just seems to make sense to me," Boyer said. "You have to know that not everything will work, but you’ve got to keep at it and give it time."