GRANITE FALLS, Minn. — Yes, corn and soybean pros rarely consider wheat or oats or even barley in your crop rotation. But if building soil health is still on your agenda, then just maybe squeezing a small grain into that formula every third year or so would do a favor to both your soils and your pocketbook!
That wasn’t the exact message from University of Minnesota Extension Crops Educator Jared Goplen, but when he mentioned upwards of $200 per acre losses when soybean aphids take a huge liking to your soybean fields, Goplen has your attention! He spoke at a small grains workshop in Granite Falls, Minn. on Feb. 20.
Said Goplen, “For the corn/soybean guys, there’s little doubt they face more weed and insect issues than farmers who work a small grain into their cropping sequence. And with production costs continuing to escalate in this continual battle of weed free and insect free corn and soybeans, small grains are getting more attention as a ‘fight back’ therapy. Include small grains and you are breaking up some of those weed and insect life cycles which can be very helpful in your management strategies.”
He noted $200 per acre losses can and do happen just from incorrect varietal choices when planting soybeans. “Soybean cyst nematodes are the number-one disease limiting pathogen of soybeans. The problem is that it doesn’t always cause above-ground symptoms, so you might be having significant yield losses and you don’t even see it. You can avert this disaster by digging a few soybean plants in early summer; or the recommended strategy of soil sampling to see what your SCN egg counts are and go from there in developing your management program.”
So are soybean cyst losses increasing year by year? Goplen hesitated, “We’ve sort of been lucky that past 10 years or so. Resistant varieties have been working well enough; but now we’re seeing these resistant varieties kind of breaking down so soybean cyst nematode is causing some higher yield losses. Seed treatments don’t seem to be the answer, so the only strategy is to manage with resistant varieties … and crop rotation. And that’s why small grains are getting back into this conversation more and more.”
He noted most soybean varieties today have PI 887888 as the cyst nematode resistant factor. However, nematodes are now becoming resistant to the resistance. So switching to varieties with Peking genetics is now a recommended practice, if you can access this breeding.
Goplen indicated Peking varieties might be limited access yet this spring. He suggested Bruce Potter, plant pathologist at Southwest Research and Outreach Center in Lamberton, Minn. as the contact guy on availabilities of these new SCN resistant soybeans. “As we get further north into Minnesota and the Dakotas, these soybeans may be more limited.”
Goplen also noted soybeans after wheat, or oats, generally produce at least a 7 percent yield bump. Plus that small grain in your corn/soybean cycle gives a break on troubling weed problems. So should the small grain be wheat or oats? “That somewhat depends on your location in the state and if there is a local market. If you’re in the southeast quadrant of Minnesota, oats are the more common choice. Here in the ‘western prairie’ section, wheat is preferred. However, besides grain yield, also consider the value of your straw crop. Weather hazards seriously reduced hay yields last year for many. And that is why upwards of $150 per acre off wheat straw bales are happening this winter.”
Barley can work too; but Goplen cautioned it is a bit more challenging crop. But he does advise the early you can get your small grain seeding in the ground the better. “Probably not in advance of St. Patrick’s Day, but if the ground is fit, get it seeded. Small grains are a cool-season crop so give them that advantage. Warm nights are the biggest detriment to healthy, productive small grains, so an early season harvest is best,” he said.
Plus, the positive impact on better weed control in your fields is a real plus for small grains. “More diverse rotations give you a management plus,” Goplen said. “Often with a corn/soybean program, you have these nuisance weeds of ragweed, water hemp, lambsquarter, etc. With small grain, you can harvest before some of these weeds even produce viable seed. That certainly helps decrease the weed bank.”
Can cover crops be part of this same strategy in both weed control and reduced disease issues? Very definitely said Goplen. “Crop rotations historically are key to building soil health. Cover crops are gaining interest particularly if you might not have a market for certain small grains. A more diverse rotation gets you a multitude of these soil health benefits and can often reduce your overall costs of crop production without a negative impact on net earnings.”
However, he graciously acknowledges when he’s talking to a group of ‘powerhouse’ corn growers, the idea of fitting some small grain into their corn/soybean routine isn’t likely to make many converts. Often it gets to the bare bones of treating every field individually because every field often is different from every other field.
“Sure, I recognize that on some fields you’re not going to make more money growing a small grain. It’s difficult to pencil in black ink if you only market the grain. But you need to give some credit to your small grains for a yield bump on either your corn or soybeans after small grains. And, if you have a strong hay market, that can be a deciding financial factor too. If small grains gives you some help in your battles with weeds or certain diseases in your fields, it’s hard to put a dollar value on this. But consider the peace of mind as a significant plus also,” summed up Goplen.