An Iowa farmer has set out to determine the effectiveness of cover crops as a broadleaf weed control mechanism.
Sam Ose, of Williams, Iowa, has utilized cover crops for roughly seven years. Even with almost a decades worth of experience, Ose believes there is always something to learn from this relatively new farming practice.
This spring, Ose set out to determine if seeding rye into a standing field of seed corn would help suppress late season growth of broadleaf weeds.
“We have three different test strips here,” Ose said. “We have a control strip, which won’t receive any cover crop. We have some that was early-seeded, in the first week of July. Then we have some where we will seed rye over the top of female corn as soon as the male rows have been chopped out, which should be happening sometime in the first couple weeks of August.”
“The hypothesis is the early-seeded strip will substantially hold down waterhemp growth later in the season. The later-seeded stuff probably will have some activity, but certainly less,” Ose said. “We’ll assess this at the end by going down the rows and comparing the number of waterhemp over two-feet tall – the breeding size – in the control strips and seeded strips, which should give us some clear indication of whether we’re actively holding down the population.”
Seed corn production is delicate, and requires producers to get creative. In his trial, Ose tried a minimalist approach to herbicides, using a one-pass system later in the season.
“We have little in the way of grass control herbicides out here, and we do have quite a bit of weed grass growing. We put down one pass of broadleaf herbicide, Laudis, which will do a decent job of holding back the waterhemp when it’s small,” Ose said. “What we’re seeing now is waterhemp growing in all of the different passes, but we are seeing pretty good residual control and are hoping the rye will grow big enough to shade out some of the weeds before harvest, or before they chop the male rows and reopen the canopy to let more light down to ground level.”
Ose is pleased with the results thus far and hopes to capture other unintentional benefits come harvest.
“We have a pretty good stand of rye where we seeded it; I don’t have any complaints on that account. I wish we had handled the herbicides a little bit different early on, but we’re living and learning,” Ose said. “The other thing we’re hoping to get out of this is erosion control, and compaction and mud issue control for harvesting seed corn, which is always a challenge. We won’t know if we get any good results until we actually harvest it.”
Ose encourages others using cover crops to experiment.
“I don’t have any other words of wisdom other than experiment,” Ose said. “Rye is cheap. If you’re buying a few bushels of it, you can throw it out with a hand spreader if you want too. There’s really no excuse for anyone to not at least have tried it once or twice to see what happens. The downside is pretty minimal.”
