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Crop watch

By Staff | Jun 18, 2019

Finally in the last month of May and first days of June we get the break in weather we have been hoping for. Farmers are incredible persaverent in getting the tasks at hand done, plus hate to admit defeat, when it is only Mother Nature and the Board of Trade they are contending with. So they worked long hours ever since the fields got dry enough to work, so the crops in a number of the delayed planting states were planted just before or as the clock was winding down. Does this mean the worries connect with raising these crops are all going to end. No, it may mean they are just going into phase 2.

Can the corn mature and yield well in the fewer days they have left? In many cases it got late enough that many growers did switch to earlier maturity hybrids. That should help if the cooler weather predicted for the second half of summer materializes. Years ago the rule of thumb was to make sure whatever mature of hybrid you were going to plant, it was necessary to have it reach black layer a week before the expected frost date.

Last weekend we headed to St. Louis for an early father’s day celebration and to see two of the grandkids. That gave us a chance to take Hwy 163 thrgh Ottumwa and into Memphis, Missouri and see the crops close up.

The client farmers I had alerted to my travels asked what crops? It turned out the corn and beans planted early on flat ground through Missouri, Oklahoma and Kansas have mostly drowned out or been suffocated. If the crops still exist it is over the tile lines or on the above grade areas in their fields. That was the case clear down to Tulsa. In fact Vice President Pence was due to fly in on Tuesday to view the flood damage.

The old saying in Oklahoma used to be that the annual rainfall was 13-inches per year, and pity the night it came. This year the big storms have marched through the state several times per week.

So those acres were once planted, but have now died. They may or may not be replanted. Which surveys will be picking up and accounting for the grain that will or will not be produced in 2019? And when will that take place. The $64,000 question is: are we raising $3, $4 or $6 per bushel corn this year? Several seasoned commodity advisors are questioning the crops people that have traveled the heartland to get their opinions on what they have seen. How much loss will there be on the late planted acres? How many poor stands will be left that should have been replanted? How many bushels could disappear with an early frost or a cool second half to the summer? How much N has been lost on each category of planted corn crop? How about yields on the later planted bean acres? Will my banker allow me funds to make additional applications that could increase my yields and benefit from the expected higher prices?


One big question now is how will the market analysts factor in the expected lower yields from the high number of acres planted later than the optimum planting window. If they plug in the trend line yield seen the last few seasons we can call them on it. We all viewed the charts of expected yield at the different planting dates and the corn acres planted in the June 6th through the 15th date was projects for 51 to 55 percent of optimum.

In reality, there has never been such a widespread problem, thus the yields seen in recent year late replanting situations could give us the best indicator of what growers can expect from those fields planted in the last ten days.

Several central Iowa growers referred to their three different corn crops. One was nearing V4, one was at V2, and one had just been planted. It may help him out by spreading out the different applications that normally must be done. It could squeeze him when two or three different tasks need to be performed or equipment switched to complete those tasks. Farmers in South America run into similar problems as they often have multiple crops at different stages with vital applications needing to be done for each.

Appearance of the corn crop and nitrogen applications

Just as in 2018 there are few normal looking corn fields. In a drive to Eagle Grove on Saturday morning we were categorizing each corn field by rating then as green, yellow, or a combination. Unfortunately more than a few received a yellow rating. Does the person owning the fields or managing the crop need to sound the alarm right now or take a different approach? Farmers now are searching for the correct answer on meeting the corns’ nitrogen needs.

Several articles are available now from good sources that provide guidance. Emerson Nafziger, extension agronomist with the Univ. of Illinois, covered it in a Farm Doc Daily column dated June 7th. He stated that the factors that have to be considered first are how much of the earlier applied N may have been lost. In lots of fields there was no fall applied N. A realistic yield goal has to be established, guided by the long term studies on yields vs planting dates. 200 or 220 Bu/A yields may no longer be in the cards with the late May/early June planted fields. Then if sidedressed or Y-dropped N, or a stabilizer will be used to boost efficiency, the normal 1.2 lbs pounds of N/Bu may be changed to 1 lb N/Bu of yield goal.

Dr Nafziger refers to work that John Sawyer of Iowa State was involved in where he tracked rainfall amounts in the April through June months. If the amount was less than 16-inches there was less leaching and the normal 180 pound N rate could be trimmed to 140 pounds. The 16-inch rainfall standard varied by exact location within the state, soil type, and OM. Dr. Sawyer looked at those parameters over a multi-year project within Iowa.

It is common to see the smaller corn turn yellow and green up as the roots reach deeper. Soil tests can verify the NO3 or NH4-N amounts in the soil, but as to how deep they should be monitored is still open to debate. Is 12, 24 or 30-inches in depth best? In healthy and biologically active soil the planted used N should be the organic fraction. This becomes confusing, especially for a year where the shortened season can penalize any delay in application.

Emerson’s recommendations were to choose a few rows in the field where additional N was applied to serve as a check strips for making comparisons to. Readings can then be made using either the $2,400 Minolta or $269 At Leaf SPAD meter comparing sufficient vs deficient areas within those strips. Now would be the time to make use of such instruments which give numerical scores.

A kit to test for residual N offered through a Yield 360 program was promoted a few years ago as a means to detect residual N to calculate additional N needs. They are not being heavily promoted now but the concept was great. There was also a sensing device/rate controller developed by John Colburn (a retired NASA Engineer), which was mounted on a high clearance sprayer and would take three different soil measurements to adjust the N rate on the go. It worked great for the few operators who had the savvy and laptop computer skills to place in the cab to make the on-the-go variable N rate calculations. It is time to have an interested Ag tech company dust off those blueprints, work with Dr Colburn’s widow, and start building them again to pair with the Y-drop systems now in wide use. Keith Schlapkohl, a Durant corn grower and college buddy, who developed the first modern Y-drop who used the Soil Doctor for years in his fields and was able to reach unbelievable N efficiency rates. Other NASA scientists continue to use their spectral analytical knowledge and skills to test for mineral levels in many different applications.

Other tissue testing

The mid-April planted corn acres are mostly nearing or at the V4 growth stage. The first streaking, indicating nutrient deficiencies, will be appearing by the V5 stage and the first of those are showing up. Not monitoring these levels or delaying the remediative application could slow the crop development in a year when each day or week is valuable. Midwest Lab is typically fast in getting the results back via e-mail. Ward Labs (4007 Cherry Ave in Kearney, NE) is also a lab that provides full service nutrient and Haney analyses. Ray has expanded his lab and has added the instrument with the capability to do the tissue Moly at no added cost.

Stands and plant populations

Over the next week growers should do some quick field scouting to see how their stands measure up to expectations. The cause (s) of any deficiencies should be sleuthed with plans to rectify the problem next year.

Bob Streit is an independent crop consultant and columnist for Farm News. He can be reached at (515) 709-0143 or www.CentralIowaAg.com

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