Issue No. 5, Article 9/April 27, 2007
Notes on an Unusual Spring
It may just be playing a word game, but when it comes to weather as it affects crops, "normal" is not the same as "average." "Normal" is within range of our expectations based on previous experience, and normal conditions range around, but seldom fall right on, "average" conditions. So nearly every spring is unusual in some way, but 2007 has been perhaps a little farther from the average than most. The cold temperatures during the second week of April have been the most unusual occurrence, along with the slow warmup since. Will there be consequences, or will the season progress as usual from here on out?
Damage to the wheat crop continues to be very hard to call, even more than two weeks after the coldest temperatures. Reports from this past week are that some insurance adjusters are predicting losses larger than we would have expected, in fields that have shown some regrowth and that have with good stands. Other fields, even those in southern Illinois, are now showing some regrowth and are looking better than expected. The most difficult decisions are in fields where some plants seem okay but others are not. I can't add much to what I said last week on this topic, other than the obvious point that fields that are torn up or destroyed with herbicide and planted to another crop will shift anxiety from seeing how the wheat turns out to seeing how the replacement crop turns out. Guarantees are hard to find.
The corn that we planted on April 2 emerged on April 24, after about 120 growing degree days. Emergence was very uniform, and there are no obvious problems caused by the seeds' having been "refrigerated" for some 10 days. It is important to note that the soil around and atop the seed stayed mellow throughout, with no crust formation at all. Heavy rains that are falling in places in Illinois on April 25 and 26 may cause soil crusting in some planted fields, which may prove to be a bigger challenge to emergence than cold temperatures have been. There have been some reports of soils being on the wet side when they were worked and planted, with some fields worked one more time than normal to get them into shape to plant. This might have improved seed-soil contact, but it may also mean greater potential to form a crust. Crust formation is not fully understood, but it is related to soil type and is usually a greater problem when soils have been wet and cool (thus slowing the emergence process) followed by warm and sunny weather, with drying wind. Rotary hoeing is the normal method for breaking up surface crusts, but this is not always effective where crusting is severe.
As we move as quickly as we can to finish up corn planting and to start planting soybean, we need to remember that damage done with soil compaction or from putting seed into poor seedbed conditions caused by working or planting fields too wet can be damage that affects the crop throughout the year. At some point it may become necessary to work and plant fields "on the wet side" because the delay in planting corn will cause more yield loss than will poor soil conditions. But we're at least three weeks away from that date in Illinois.--Emerson Nafziger