Don’t “S”kimp on the “S”

Research is Showing Support for Sulfur!

With the 2017 wheat harvest long in the books, we now have time to roll up the data and crunch the numbers.  There was an interesting conversation sparked last week at our office between Rob, Mike and myself.  The discussion began with a couple of questions about what was observed in the OCCC spring cereal trials.  In many cases in Hard Red wheat, there often seems to be a see-saw dynamic in the relationship of Yield and Protein.  Historically, as a generalization, we have seen many times where the highest yielding fields produce grain with lower protein scores, and the lower yielding fields produce grain with higher protein scores.  Obviously, farmers are striving to create the highest of each.  There are three scenarios this year that have lead us know Sulpher is very important in high yield wheat.

The first scenario was that of the Palmerston OCCC trials.  Our initial question was “What was the average gain in yield for including fungicides in the managed trials in Hard Red Spring Wheat?”  Reply: “The managed areas had 6-10 bu higher yield, or sometimes more.”  Next Question: “How much did the protein score drop given the extra yield?”  Reply: “Actually, no drop in protein range or average.”  And there were some yields in excess of 90 bu/ac.  Interesting.  With this in mind, we looked at the fertilizer approach used in this field.  A six year old soil test revealed strong soil test values for P, and healthy levels of OM and K.  Starter broadcast 40N and 12.5S (MESZ) pre-plant incorporated May 10.  Followed by liquid Topdress Application with streamer nozzles 90N and 10S Jun 13 (approximately GS Z30-31).  A very aggressive fertilizer approach lead to strong yields and many protein scores well over 12.0%.

The second scenario involved some independent agronomic research that we supported that involved some replicated small plot evaluation of nine different fertility approaches in a Hard Red Winter Wheat field.  In this case, we learned many things.  As expected, the least aggressive approach was the least productive.  A single application of 80N and 8S at green-up only produced 96.0bu/ac and 8.2% protein.  Better yield than originally expected, but still not acceptable given low protein.  At the opposite end of the scale, the most aggressive approach was most productive.  The multi-pronged approach with 80N and 8S at green-up, plus 80N and 11S at flag leaf (AMIDAS), plus a foliar fertilizer added to T3 spray produced 115.1bu/ac yield and 10.9% protein.  Much better!  A clear statistical trend in the data supporting the use of S to create strong yields, and strong protein.  Only a single year of data, but we do plan to repeat.

The third was observed through watching the Real Wheat Growers episode where the grower produced more than 150bu/ac on a large farm!  Very Impressive!  It was mentioned that this crop received a very heavy dose of fertilizer at the “boot stage”.  The product used was AMIDAS which provides N and S, and although I am not certain that the total values applied were provided, I would guess given the description that it was greater than 150N and 20S net total.  Given that this was a soft red wheat crop, there was not a report of a test done on protein.

It has to make economic sense also, be sure to do the math on the change you plan to make.  We have certainly seen many examples when additional investment of $20-30 per acre in fertilizer can return much more than that in yield or protein premiums, or both.

We intend to play around with a few strategies and evaluate the response to Sulpher in some wheat crops again in 2018.  But for now, as you pencil out your fertility plans for your wheat crop in 2018 please pay attention to Sulpher in conjunction with your Nitrogen.  Based on the above observations – In cash crop scenario, the absence of manure or other amendments, I feel there is good value in applying minimum of 20S in SRW and HRS, and 30S in HRW.  It may be valuable to go even higher than this, but try a few strips first to learn how your crop reacts.  It is exciting to see the responses that a wheat crop will give!

“S”plit application, and “S”ulpher are certainly two key areas for focus when you build your 2018 wheat fertility plan.

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