Heat, Dryness Take Toll On Soybean Crop

Iowa Farm Scene

End of summer drought conditions have reduced Iowa's soybean yield potential, as well as corn.

Published on: September 9, 2013

In last week's blog we asked "Will Your Corn Beat the Frost?" This week we look at how Iowa's soybean crop is doing, especially the late planted beans. Wayne Fredericks is secretary of the Iowa Soybean Association, farming near Osage in northern Iowa, near the Minnesota border, about 30 miles east of Mason City. His area of the state has a lot of late-planted, late maturing beans this year. Many acres didn't even get planted, as spring was so wet. How do the late-planted crops look now?

Many of Iowa's "prevented planting" acres this year are in north-central and northeast Iowa

"We got hit with 13 inches of snow here in Mitchell County the first few days of May," says Fredericks. "Virtually no crop was planted in our area prior to that time. When we finally got into the field in mid-May we only had about three days where we could plant, and it was a bit wet. We got a lot of our corn planted in mid-May, but not all of it. There were only a few soybeans that went into the ground at that time in this part of the state."

HOLD THE FROST UNTIL THANKSGIVING: Yield predictions for 2013 from Iowa farmers depend on where localized rains fell this summer and on how late the beans were planted. Much will depend on when the first killing frost hits this fall. Many growers predict average or slightly-below average bean yields assuming normal date for first fall frost.
HOLD THE FROST UNTIL THANKSGIVING: Yield predictions for 2013 from Iowa farmers depend on where localized rains fell this summer and on how late the beans were planted. Much will depend on when the first killing frost hits this fall. Many growers predict average or slightly-below average bean yields assuming normal date for first fall frost.

He adds, "It wasn't until June 5-6 that we got another day or so to plant. We got another day or two around June 11 and then June 18-20 we had a short spell where a lot of beans were planted. And those of us who still had beans to plant finished about the 5th of July. Of course, a number of farmers took the 'prevented planting' option offered by crop insurance so those fields weren't planted to corn or soybeans this year."~~~PAGE_BREAK_HERE~~~

How many acres went unplanted? About 35,000 acres in Mitchell County. In Mower County just across the border in Minnesota it's 75,000. Howard County, Iowa, also has a lot of prevented planting fields. How about the beans that did get planted in that area of Iowa -- how do they look now?

Planting was so spread out, there are basically four crops of soybeans in northern Iowa this year

"We basically have four crops of beans in Mitchell County and the surrounding area," says Fredericks. "A few large farmers planted corn and beans at the same time, got them planted at a decent time. Those beans are now starting to turn and look real good. Our first beans on our farm were planted June 5. They look pretty good now in early September; they're still green, done flowering, podded pretty well, now starting to fill pods. They have potential, barring an early frost, of making average yields."

The next crop of beans Fredericks planted was on June 18, 19 and 20. Those beans, as of September 6, have 16 to 17 nodes and are still flowering, he reports. They're starting to pod pretty well. But the pods are relatively flat yet. "We still need a lot of time to fill those pods. But the beans are healthy," he adds.

The last crop of beans, are those that farmers finished planting in early July. "As of today (September 6) they are a little bit more than a cover crop," says Fredericks. "They have an average of 10 nodes and if you're lucky you might find 10 pods. They're still flowering."

Fredericks on September 5 attended the monthly ISA board meeting in Des Moines. The 18 or so farmers on the board reported on crop progress they're seeing back home. What kind of yield prospects do they see?

Stifling heat and dryness in late summer has taken a toll on Iowa crops in 2013, but farmers are still hopeful

While most of Iowa's 2013 bean crop got off to a late start due to the record wet spring and delayed planting, the dry summer and stifling heat at summer's end has taken its toll, too. Harvest predictions from ISA members vary according to localized summer rainfall. Some say crops on sandy soils are a complete loss, others expect good yields given the challenging growing season and many are predicting average or slightly below yields.~~~PAGE_BREAK_HERE~~~

"We were blessed with 3 inches of rain the first part of August here in Mitchell County," says Fredericks. "So we are now sitting with a pretty healthy bean crop. We've been inundated with soybean aphids this year. Most farmers growing soybeans in this area sprayed insecticide in August to control aphids."

"Our crop is still healthy and we have moisture in early September," he says. "The balance of the state of Iowa is in reverse. The crop is drying up, beans are running out of moisture and a lot of corn and beans are being pushed faster toward maturity by the heat and dryness. Farmers in the driest areas of Iowa are concerned about lack of yield due to dry weather. But our concern in northern Iowa has to do with late planting. We're worried about an early frost potentially coming along before the beans are mature."

Concern about bean yield potential in Iowa this fall varies significantly across the state

So we're seeing concerns about yields from both ends of the spectrum for very different reasons, he notes. A farmer in Wright County in north-central Iowa says there was a lot of spraying for aphids in August. Was aphid spraying statewide this summer or isolated in various spots in the state? "It was isolated, mostly in northern Iowa," says Fredericks.

He adds, "We're seeing this pest in north-central and northeast Iowa, and the aphid infestations were worth the time and effort to spray. My crop consultant says this year is the most rapid growth in an aphid population he's seen in his career. It was only two or three days, but aphid populations just exploded in the Mitchell County area."

Soybean aphids, along with recent hot, dry weather, have been a challenge for some Iowa growers in 2013

"We were on top of the aphid problem, with a timely spraying of insecticide," says Fredericks. "But the plants were loaded with aphids. Talking with other ISA directors from around the state, aphid populations haven't been a concern for most of them. But aphids were a problem in some northern Iowa fields this year."

It'll be very interesting to see how this year's Iowa bean crop plays out. A lot will depend on the first killing frost, when it comes. The normal date for the first killing frost in Fredericks' area of Iowa usually occurs at the end of September, the last few days of the month.~~~PAGE_BREAK_HERE~~~

"If the frost comes at the normal time, it's going to cut into our crop in Mitchell and surrounding counties, probably pretty severely," he says. "But if we happen to get a warm spell which carries us into mid-October, the situation will be a little more acceptable for us up here in northeast and north-central Iowa. Thanksgiving would be a great Thanksgiving if that's when the first frost comes."

Cool weather in July and first half of August held the Iowa crop behind in development

The weather in Iowa stayed cool through July and first half of August, "and we actually lost a number of degree days," says Fredericks. "We were about six weeks late planting and then we lost some more weeks due to cool weather -- about 5. Thus, we are about two months behind. We made it up somewhat with heat the last half of August and into September, but we're basically two months behind. The recent heat has been a blessing for most of our beans on our farm, especially since we've had some rain, which provided some moisture for the plants to work with."

No-till beans really help save precious soil moisture, and precious time this year

On September 6 he observed, "We continue to need a shot of rain to really be of benefit to soybean yields, we'll know how it pans out in another month. We'll have a lot better idea of what the potential yield is going to be for soybeans in Iowa."

Fredericks no-tills his beans. Do those beans look better than conventional tillage beans do in a dry summer? "Our no-till beans have yielded well," he says. "This year no-till gave me a big advantage. When the ground was fit to plant last spring, I was able to get right in there and plant thanks to no-till. I didn't have to worry about working soils and getting the field ready to plant. This year, we used every available minute to put seed in the ground. If I would have been using conventional tillage, we wouldn't have gotten nearly the amount of crop acres planted that we did."