Farmers selecting a cover crop for prevented plant acres should carefully consider the impacts of that choice.
“This year has thrown a lot of unprecedented circumstances at us that most of us in this room have probably not experienced before,” said Laura Lant, agronomist for Midwest Grass & Forage. “There is no perfect solution that fits everyone.”
There are a lot of considerations to take in account, Lant noted, during a presentation at the Illinois Forage Expo, organized by the Illinois Forage and Grassland Council.
“We’re trying to make the best choices we can, and we don’t want to screw up our 2020 crop,” she stressed.
One of the first considerations is if herbicides have been applied to the field.
“Look at the labels because there is no point putting a crop out there at $30 to $50 per acre if it is not going to grow,” Lant said.
“The second thing I would consider is your equipment,” she said. “If you don’t have equipment that can handle a crop with a lot of residue, choose something that won’t produce a lot of residue. Summer crops can produce vast amounts of residue that we will need to incorporate this fall or plant through next spring.”
Some cover crops can be hosts for corn and soybean pests.
“Oats and cereal rye can be great options this fall, but you don’t want to plant them too early,” Lant said. “If you plant those crops in July, a lot of eggs can get laid on them which could affect the corn or soybean crops the following year.”
“We would like you to utilize your equipment and herbicides for controlling weeds in June and July and not risk putting the cover crop out too early,” said Doug Hanson, seed specialist, ProHarvest Seeds. “What cover crops can do for weed control when they are planted in August and September is not the same when you plant them out of season.”
In late June and early July, Hanson said, one option is to plant the summer annual millet.
“You can make dry hay from this summer annual, and it needs to be harvested 45 to 50 days after planting,” he said. “It’s a great option for those who are short of feed, but the supply of seed is tight.”
Sorghum-sudangrass is great for baleage or chopping for feed, Hanson said.
“This crop is ready for harvest 45 days after planting,” he said.
“Summer annuals like sorghum-sudangrass or forage sorghum can produce prussic acid,” he said. “You need to work with someone who knows what they’re doing.”
Hanson also told farmers to use caution if they are thinking about planting bin run oats or wheat.
“You might bring in weeds you don’t have because bin run oats or wheat were never intended for seed,” he said. “You might save $10 per acre this year on the cover crop, but they are not germ tested and you don’t know the quality.”
In Short Supply
Since availability of cover crop seed is tight this year, Lant advised farmers who will need seed in the fall to start talking to their seed supplier now.
“Oats and rye will be hard to come by until the new crop is available,” she said. “We thought supplies were tight last fall, but it is going to be five times worst this year.”
“We’re not selling straight oats to anybody. The only way you can get oats is through a mix,” Hanson said. “We believe oats and radish are the best way to control weeds, help prepare a field for next year, and they are very simple to deal with and easy to manage.”
“Mixes with 10-plus species can be good for the soil, but for folks that haven’t done cover crops and don’t have the specialized equipment, we recommend taking the simpler approach,” Lant said. “Not necessarily a single species, but a mix like oats and radish or annual ryegrass and radish.”
Lant also encouraged producers to consider the variety when selecting seed.
“Our radish plots went in during early May,” she said. “One of the three varieties has already bolted, so I’m not recommending that variety for early August planting.”
Some radish varieties are suspected to be hosts for soybean cyst nematode and others are not, Lant said.
“Consider that when buying seed,” she said. “Usually the additional cost is minimal at $3 to $4 per acre.”