Renewable Farming

What’s behind 280-bu. corn on this rolling, “low” corn suitability rating soil?

January 14, 2017 –Excerpts from consultant Bob Streit’s weekly crop update:  I have previously mentioned that in working with a friend and ag professional on his farm just west of Guthrie Center, and other individuals across the state, we were seeking high corn yields in 2016. When we combined different products on a 31-45 CSR field, we managed to raise corn yields into the 280 to 340 bushel-per-acre range.

Now the challenge is to dissect the season and system and figure out what inputs or soil parameters were responsible for the good results. In a scientific experiment only one variable is changed, so its effect can be measured. But in the real world and actual field growers will usually change several things if each of those individually make sense.

Yields were extremely good with:

The use of stabilized nutrition (N with Nutri-Sphere and P with Avail) that were row-placed and broadcast and timed more to plant use,

Futuristic signaling compounds like “Take Off” that promote nutrient scavenging and efficient utilization, and

Ultimate disease control (for both bacteria and fungi with a Bio Empruv mix) that kept the corn plants green through late October. 

In most cases where the grain is dumped in the cart and bin, that’s the end of the story.

In this case we saved ears off the Guthrie County and other farms and it was time to do more analyses. So now the ears, which showed no tip-back and most had kernels that went up and over the end of the ear, were dissected with kernels being pulled out each inch of the ear. They were analyzed for the full spectrum of minerals with an X-Ray defraction instrument to see what mineral component differences existed in the kernels from the butt to the middle to the top of the ear.

The thought was that when mineral availability tapered off due to lack of those minerals within the root zone, inadequate soil biology to convert the insoluble fertility to the reduced/available form, or adequate plant health to keep the plant pumping out sugars, the kernels analyses would show when and where and which deficiencies had occurred.

Pictures of this dissection and footage of the work was captured and soon the action and graphs of the findings presented in a 30-minute video in the very near future on our website

We were able to get the participation in this project by several of the top scientists in the country. Four PhDs from M.I.T. and several from other major universities were involved and all of them have lots of hands-on field experience. You will recognize most of them when you watch the video.

In addition, soil samples were pulled every month and analyzed using the traditional methods and run through the Haney analyses. Thus the biological components were grouped into either fungal or bacterial categories as well as the micro-fauna as to whether they were amoeba (blobs), flagellates (flippers) or ciliates (finned). The samples were given an overall Haney score.

Different types of N stabilizers were tested with the results graphed and the differences were remarkable. Some lowered the Haney scores dramatically while others raised them. Growers who hope to march up the yield ladder, and stay price competitive may want to try to duplicate the program that was used here.

A number of those farmers are likely to attend the upcoming ISU Extension Soil Health conference scheduled for late February. They will want to hear what practices and products are best for improving the soil and production scheme and hopefully which ones are harmful and should be weaned away from.

After we get all the analytic results I hope to show them to the Soil Lab director as well as other seasoned ag experts and tease out what ideas are most important and should be expanded. As someone who sees major soil loss problems and depletion of nutrients in the soil bank, giving guidance on how to restore soil productivity and its needed biological activity, getting such work done to help growers stay on the right path is important.

Some of the thought process behind the intense grain analysis comes from my growing up around hogs and other large-littered meat animals. When the sows runs out of dietary and stored energy and minerals halfway through the gestation, and produce 10 baby pigs, number 8, 9 and 10 are often runts being they were on the end of the umbilical cord and food supply. The runtiness stays with them throughout their lives and ends up costing money.

Now if the corn or soybean plant runs out of nutrition half way through the grain fill, it makes sense that the last formed kernels and seed will be smaller with fewer nutrients in them. With the quick, non-prep, real-time ability of the x-ray defraction equipment farmers and seed producers will be able to test first versus last formed grain to track mineral levels and manage the crop for optimum fertility.

Running out of minerals and energy could explain emergence, low seedling vigor and early disease susceptibility issues seen in recent seasons.


Soil test results

Now is when many farmers have time and the need to go over the results of last fall’s soil sampling done on their farms. From what I have seen, too many of the analytical report results are still short of what is needed to figure out what needs to be done to correct problems.

Too many are missing base saturation and any micronutrient testing. I still like to see every third or so of soil samples tested for micros. Then if any red flags are raised on the third there is typically three weeks where the samples are shelved in case there are requests to rerun them for additional tests.

If there will be no more dry spreader passes made before the planting season the appropriate method of applying zinc would be to go in furrow application of chelated zinc. Ditto for the molybdenum, which more samples are never tested for but should.

Since boron can get hot and burn root tissue it is best applied with a foliar application. The same applies for copper and manganese since they are ending up being short in tissue testing a high percent of the time.

ISU Crop seminars

Another meeting series being held the next few weeks across the state are the Crop Advantage seminars. Check with a local Extension office to see when the one in your area is scheduled.

Bob Streit is an independent crop consultant and columnist for Farm News. He can be reached at (515) 709-0143 or The complete weekly summary will be posted on the Central Iowa Ag website.