Why You Should Consider Adaptive Nitrogen Management for Your 2016 Corn Crop

Corn needs nitrogen.  A 20 ton/ac corn crop removes 180 pounds of nitrogen from the soil.  That nitrogen comes from manure, decomposing soil organic matter, fertilizer and a small amount is deposited when it rains.  A certain amount of nitrogen is lost when manure is applied (from ammonia volatilization), and other losses include leaching, IMG_1390denitrification, and fertilizer (urea) volatilization.  In some cases, such as when the cover crop gets too mature, otherwise available nitrogen can become immobilized for more than a year.  With all of these potential losses and other dynamics, how can one predict how much additional nitrogen fertilizer (if any) they will need to reach their corn yield potential?

By now, most of you have probably heard about the Adapt-N tool that Cornell developed several years ago; some may even be tired of hearing about it.  This software is roughly analogous in concept to the ration-balancing software that your dairy nutritionist uses.  In the same way that you don’t use your 2014 forage tests to develop your 2016 rations, the Adapt-N program will only give good information if you feed good and current information into it.  The program needs data for each field including: expected yield, planting date, relative maturity of the hybrid you planted, plant population, manure test information, manure application dates, date of manure incorporation, soil organic matter, GPS location, etc.  This allows the program to model nitrogen behavior in the soil, crop development, nitrogen demands, etc.  It will even give you a ‘virtual pre-sidedress nitrate test (PSNT)’ that you can compare to a physical PSNT if you want to ‘ground-truth’ the program.  It is a TREMENDOUS program.   That said, no approach to N management is perfect.

  • Guessing or just applying the same amount of N every year is a very bad idea.Some years you could run short and lose 30% of your yield.  Other years you will over-apply and have environmental losses and a poor return on your investment.
  • The PSNT can give good information, but between rocks that make sampling frustrating, trying to make hay, heat, labor, and other factors, it rarely gets done and often results in getting the recommendation too late.  While the PSNT can yield a good recommendation and is certainly better than guessing, it is mostly blind to present and past weather conditions and often ends up over-recommending sidedress N.

The pieces of information that farmers often do not have and which often prevent them from being able to use Adapt-N are 1) a  current soil test (to give us the organic matter number), and 2) current manure test reports/application rates.  If you have those pieces of information for your farm, you are in a good position to try using this tremendous tool during the 2016 growing season.Adapt-N rec

What if I think the recommendation is wrong or scarily high or low? 
Adapt-N WILL generate a recommendation, but we still need to use common sense.  If the recommendation seems too high or too low, the reasons for that need to be investigated.  An artificially low soil organic matter level will result in an extremely high N-recommendation and visa versa.  I worked with a farmer last year whose soil test report indicated 1% soil organic matter.  That is a very low number for Vermont, but I put it in.  It yielded a MASSIVE N-recommendation.  The farmer said, ‘I never put any sidedress N on and I always get 25-ton corn.’  Well, he was right.  The corn field looked great except for some spots around the edges that were torched/stunted from N-deficiency; the stalk nitrate test also indicated that the plants had adequate amounts of nitrogen available to them.  The places in the field that were clearly N-deficient were likely extremely sandy and represented low organic matter and high levels of leaching.  The soil organic matter level in the field overall was probably significantly higher than 1%.  It is a good tool, but it still needs to be informed by common sense and experience.

Two other virtues of the program compared with the PSNT:  1) you can get set up in Adapt-N now rather than late-June (as with the); and 2) it will email you nitrogen status updates on a regular basis, informing you of any major nitrogen loss events.

If you are interested in using this program for the 2016 growing season, get the aforementioned records together and contact me (djhudson@uvm.edu or 802-535-7922). I would be glad to show you how to run the program and help you get recommendations for several management zones (at least) on your farm.  Agronomic Technologies (the company that owns the Adapt-N license) has given me quite a few acres ‘free’ to introduce the product to farmers, other acres can be covered for about $2.50/acre.

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New UVM Nitrogen Recommendations for Corn are Coming!

With genetic improvements that have increased corn yield potential and the advent of good alternative approaches for determining in-season crop nitrogen need (i.e., sidedress N), it is evident that the UVM recommendations for nitrogen fertilizer on corn need to be updated.  While the entire document Nutrient Recommendations for Field Crops in Vermont will be revised next year, we will soon (within the next day or so) be releasing an addendum to that document that will serve as the UVM nitrogen recommendations for corn production during the 2016 growing season.  The revisions are not earth-shattering, but do account for the aforementioned realities.  Stay tuned!

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Better Bunker Silo Management

In this video from the 2016 Vermont Agronomy Plus series, Dr. Limin Kung, Jr. (University of Delaware) describes best management practices for minimizing the losses and optimizing the quality of feed stored in bunker silos. Small management changes can have big economic implications for your farm!

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Can Corn Be Grown in a Living Mulch?

Last week I posted a video on the subject of growing corn in a living mulch in Georgia.  This video covers a similar topic, but with a different legume and a different environment.  In the first part of the video I cover some of Ken Albrecht’s (University of Wisconsin) work on growing corn in a living mulch in Wisconsin.  In this case, however, the legume species is kura clover (a little-known clover that spreads by rhizomes) rather than white clover (which spreads by stolons).  Because this was delivered to a different audience than Nick Hill’s initial presentation, I also included some of his video in that presentation.  The result is poor audio for the second part of the video.  If you get to that portion of the video and want to see Dr. Nick Hill’s talk in its entirety, you can click the link at the top of the video or you can find the presentation below (agronomator.com).

 

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Strategies to Increase Digestibility in Corn Grain and Silage

In this video, Dr. Luiz Ferraretto discusses considerations for maximizing starch utilization in dairy rations.  Concepts include kernel processing (including a simple field-evaluation of kernel processing), time in storage, starch type, fecal starch testing, and other important dairy nutrition concepts.

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Growing Clover in a Living Mulch, Part I

Nick Hill (University of Georgia) joined our 2016 Vermont Agronomy Plus series and shared his experience developing a ‘living mulch’ system for growing corn in Georgia.  Yes, there are many difference between their environment and ours, but the concept is worth contemplating and experimenting with in certain areas of the Northeast.  More on this later.

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Managing and Minimizing Environmental Mastitis

Environmental mastitis is a serious economic issue on U.S. dairies. In this video Dr. Pamela Ruegg (University of Wisconsin) shares practical and valuable insights into maintaining and promoting udder health.

 

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