After two months of seemingly endless rainfall, many farmers in Crawford County and across the state are faced with hard questions about this year's corn and soybean crops.
"A short break from rain the last few days of May has allowed some planting, but many fields remain wet, some have water standing, and there is no expectation that things will dry up soon to allow widespread planting," said Emerson Nafziger of the Department of Crop Sciences at the University of Illinois.
"The entire state of Illinois received above-normal rainfall in May, ranging from 1 to 2 inches above normal in the southeastern edge of the state to as much as 8 inches above normal in northwestern Illinois," Nafziger continued.
"Some areas had some planting days early, but there have been no wider windows across the whole region to get the crop planted."
Forty-five percent of the corn crop and 21 percent of the soybean crop was seeded as of Monday.
A year ago, producers were almost finished planting. Corn planting was complete and beans were at 93 percent. This compares to the five-year average of 98 percent for corn and 84 percent for beans.
Thanks to rainy weather, there were two days suitable for fieldwork last week. There have been fewer than five suitable days in the past month.
Locally, conditions were somewhat better than the state average. Only .48 inch of rain was reported, compared to the average of 1.79 inches, .83 inches above normal.
Statewide, the average temperature was 70.3 degrees, 3 degrees above normal. The average daytime high temperature in Crawford County was 82.4 degrees, while the overnight low was 63.
The weather continues to have a negative impact on winter wheat, too. Condition of the crop is rated at 6 percent very poor, 16 percent poor, 48 percent fair, 27 percent good and 3 percent excellent.
Nafziger explained by late May and early June every day of delay costs corn and bean yields.
"We don't want to get stuck in the field or plant where seedbed soil is too wet to crumble, but it makes sense to start planting even though we know heavy equipment will cause compaction," he said.
"While the formation of a physical barrier to root growth isn't desirable, compaction can actually help water to move from deeper in the soil to the roots."
Nafziger said a recent paper from Iowa State University reported yield losses of about 25 percent, or 55 bushels, for corn planted June 10. The loss jumped to 40, or 88 bushels, on June 20 and 61 percent, or 133 bushels, on June 30. Therefore, planting corn on the last insurable date (June 25) would be expected to produce about half the normal yield.
"There is some anecdotal evidence that yields could exceed those numbers, but for now that's the best guess we have," he said.
Yield declines should be less steep for beans. Yields may reach 50 percent of early-planted yields by early July in south-central and southern Illinois. Yields for beans planted in late June or later in central and northern Illinois are strongly affected by growing-season weather and are expected to vary widely.
Soybeans planted after mid- or late June in northern Illinois may not mature before frost.
Nafziger said farmers may consider switching corn hybrids or soybean varieties to ones with earlier maturity.
According to predictions based on growing degree days left in the season after a given planting date, some hybrids, especially in northern Illinois, might need to be exchanged for shorter-maturing ones.
"Because planting a hybrid late usually lowers its GDD requirement, it might still be safe to plant normal-maturity hybrids in central and southern Illinois, if planting can be done before mid-June," he added.
Asked about switching from corn to soybeans, Nafzinger pointed out the answer involves crop insurance, current crop prices and how much has already been invested in fields that were to be planted to corn.
Corn is the answer when considering corn prices relative to soybean prices; the fact that corn will not be planted as intended in places such as flooded river bottoms; and the fact that in some places in recent years corn planted in early June has yielded well.
"It's not an automatic decision to switch to soybeans when planting late like it might have been a few decades ago," he said.
It's still possible farmers could see respectible yields. Trendline yields for Illinois corn and bean in 2019 are about 190 and 67 bushels per acre, respectively.
"It's too much even for an optimist to hope that actual yields in 2019 will reach those levels, but if we get the best weather possible - no temperatures above normal and not too many days below normal - and no lack of soil moisture ever during the growing season, we might hope to see yields in the vicinity of 90 percent of those trendline yields," Nafzinger said.
"Even that is an audacious hope, but we haven't tested today's hybrids and varieties under such conditions in the past five years and we can hope to be surprised at what they can do," he added.