A full week of dry weather allowed Iowa farmers to gain ground on planting their 2008 corn and soybean crops. All Iowa crop reporting districts now have over 50% of their corn acreage planted—as of May 18. Corn has emerged in many fields in recent days and the corn plants have started growing with the warmer and drier weather and warmer and drier soils.
That's according to the weekly crop weather and conditions report issued by Iowa Ag Statistics Service on May 19. The weekly government report is based on statewide surveys and this one was conducted as of May 18. Thus, the state's 2008 corn crop is 78% planted as of May 18. That's behind last year's 88% planted by that date, and the 92% planted based on the 5-year average.
Soybeans are 34% planted in Iowa as of May 18. Last year at this time the survey showed that 50% of Iowa's soybeans were planted. The 5-year average for beans is 53% finished planting by the May 18 date.
Time to start scouting corn and beans
"Things are looking a lot better than they were two weeks ago," says Roger Elmore, Iowa State University Extension corn agronomist. "Iowa has a lot of corn coming up now, and a lot of soybeans are getting put in the ground here in Iowa. Hopefully, with the next couple of days of dry weather and warm temperatures, farmers will finish up the job of getting the 2008 corn crop in the ground."
Does Elmore feel like most of Iowa's corn was planted right or wrong this year? "The corn that was planted in early to mid-April, some of that corn is coming up very well," says Elmore. "It was planted into pretty good soil conditions. Next, the weather turned cold and wet across the state and a lot of corn was "mudded in" and then it stayed cold. So now we are starting to hear about some issues regarding poor corn emergence, due to muddy planting and cold, wet soil."
Elmore adds, "Now, during the last few days—about May 16 to 19, here in central Iowa, I think we're seeing our best planting days so far this spring in much of Iowa. My advice to farmers is to keep putting that corn in the ground. This should be a great planting week."
Some corn having difficulty emerging
"There have been some reports of soil crusting and some farmers are rotary hoeing," says Mike Owen, ISU Extension weed control specialist. "A nice gentle rain shower after everyone is done planting of course, would serve to soften that soil crust and allow for better, more uniform emergence of both corn and beans."
Alfalfa is doing ok this spring in Iowa, except in the northeast part of the state where it was hit hard by winterkill. "We have had reports of scattered but very few in number, fields with infestations of alfalfa weevil," says Owen. "Generally the alfalfa crop looks good in Iowa this spring. There have been some discussions in northeast and eastern Iowa that maybe the stands aren't quite as good as you would like. So those farmers are going to go ahead and harvest the first cutting of alfalfa and then probably plant some corn in those fields in late May or early June and then cut the corn for silage next fall."
Owen has heard farmers discussing going back to corn in some cases in fields where they'd planned to plant beans in 2008. Corn prices have strengthened relative to beans in the last two weeks. "So it will be interesting to see what the planted acreage of corn and soybeans end up at this spring. With the wet spring, we have a lot of weeds growing in corn and bean fields this spring, and farmers are going to use a burndown treatment of herbicide, prior to planting," he says.
Watch corn for emergence problems
If you see emergence issues for corn, what we know is that if half of the plants come up about a week later than the other half, then you're going to see about a 6% yield reduction. So that's not a good thing. "I tell farmers to go out and look at their stands and assess what they have. They may need to replant."
The other issues ISU agronomists are seeing this spring have to do with reduced corn populations. "For every 2,000 plant reduction in stand below 35,000 plants per acre—you're talking about a 1% yield reduction. Those are the kind of numbers we think about when we consider replanting or assessing the current stand of corn in a field," says Elmore.