Webinar: Managing Fall Fertilization

Fall fertilization offers several benefits, including lightening the workload throughout the year and ensuring nutrients are available in the spring. It also helps growers manage time, crop nutrients and, ultimately, the bottom line.

The use of best management practices and fertilizer-efficiency products can produce savings by protecting applied fertilizer from losses. This was the subject of CropLife Media Group’s Webinar “Managing Fall Fertilization,” presented by Gary Tuxhorn, agronomy technical services manager, United Suppliers Inc., and Jake Sanders, Specialty Fertilizer Products’ (SFP) vice president of market development.

Soil Testing

During the Webinar, Tuxhorn discussed crop response curves, application methods and soil testing and interpreting results.

There are two basic levels of the crop response curve, he said. “In the first level, there are visible deficiency symptoms,” Tuxhorn said. “For example, if there’s a phosphorus deficiency, you’d see a shortening of the internodes. For nitrogen or sulfur deficiencies, you’d see a yellowing of the plant.”

The other level within the crop response curve is what Tuxhorn called “Hidden Hunger.” “You don’t have obvious visual deficiency symptoms, but you’re also not getting the yields you’d like to see,” he said.

The crop response curve is typically divided into five soil test zones: Very Low, Low, Optimum, High, Very High. “We can use these five zones to guide us to how much fertilizer to apply,” he said.

Tuxhorn said there have been four basic methods of applying fertilizer over the years. They are:
Mining. Mining the soil means applying less fertilizer than what is being taken out with the crop.
Build. With the build method, the amount of fertilizer being applied is adjusted depending on the soil test category.
Maintenance. One of the older fertilizer application methods, maintenance programs require whatever fertilizer the crop removes, the same amount is re-applied regardless of soil test category.
Sufficiency. The sufficiency method varies according to optimal economic return during the year of application. “Nitrogen (N) has been applied using this way for a long time,” Tuxhorn said. “A lot of universities are now recommending a sufficiency approach with phosphorus and potassium.”

Interpreting soil test categories can be challenging, Tuxhorn said. “Soil testing can vary lab to lab and state to state,” he said. “You must make sure the soil extract is the one that is calibrated for the response curve that you’re looking at. Also, be careful that you are explaining soil tests to growers as they apply to their farm.”

Phosphorus Management

Soil chemistry is more complex with phosphorus (P) than it is with other nutrients, Tuxhorn explained.

“After application, P reacts with soil cations and ‘converts’ to much less soluble forms,” he said. “Crop recovery is limited to 5% to 25% of applied P fertilizer during the season of application. That’s in contrast to N where we’d typically see 40% to 60% get into the crop.”

Several practices for managing P fixation have been used over the years, Tuxhorn said, including applying extra P, banding P, banding P with anhydrous ammonia and banding with humic acids. But one of the most recent crop management tools for improving P uptake is AVAIL.

“University research shows that 75% to 95% of P gets tied up in the soil,” SFP’s Sanders said. “This means the farmer is spending money and yet the product is not getting into the plant.”

This happens because P has a negative charge on it just like a magnet, and it comes together with other elements in the soil that are positively charged, Sanders explained. These elements tie up that P and leave it unavailable to the crop that year.

Introduced by SFP, AVAIL P fertilizer enhancer is a water-soluble polymer with a very high negative charge, Sanders said. When that polymer is used as a coating on granular P or mixed into fluid P fertilizers, it diffuses out in the soil and interfaces with those positive charges that would typically tie up the P.

“So we can hold those positives in that AVAIL polymer for about 10 to 12 months, and that’s going to give a good season of P availability,” he said.

Leave a Reply

Featured Stories
StewardshipBayer Entomologist Issues Statement On Annual Honeybee Losses
May 13, 2015
Richard (Dick) Rogers, Principal Scientist / Entomologist, Bayer Bee Care Center for Bayer CropScience LP, today issued the following statement Read More
Monsanto Sign
Eric SfiligojThe Cat & Mouse Game Between Syngenta And Monsanto Begins
May 11, 2015
Last week, I talked about how two crop protection industry giants, Syngenta and Monsanto, had engaged in some acquisition discussions. Read More
Syngenta
Eric SfiligojWill Monsanto And Syngenta Combine This Time?
May 4, 2015
Under the heading of “never say never,” it sounds as if crop protection/seed giants Monsanto Co. and Syngenta are once Read More
Eric SfiligojThe Need To Defend Production Agriculture
April 27, 2015
Last week, I spent the better part of my time on the road visiting with ag retailers and market suppliers Read More
Top 100 Articles
CropLife 100The Andersons Acquires South Dakota Plant Nutrient Manufacturer Kay-Flo
May 20, 2015
The Andersons, Inc., ranked No. 22 on the CropLife 100, has purchased Kay Flo Industries of North Sioux City, SD. “This Read More
CropLife 100North Central Farmers Elevator, Wheat Growers Unification Approved By Board, Still Awaits Member Approval
May 13, 2015
The Boards of Directors for North Central Farmers Elevator (NCFE) and Wheat Growers (WG) have voted to approve the Unification Read More
CropLife 100AgGateway’s Barcoding Initiative Progressing Nicely
May 8, 2015
According to legend (or Wikipedia), the first step towards modern bar codes came back in 1948, when Bernard Silver, a Read More
CropLife 100Pinnacle Agriculture Acquires Minnesota Retailer
April 14, 2015
Pinnacle Agriculture Holdings, LLC, ranked No. 6 on the CropLife 100,  has successfully acquired Liebl Ag, LLC in Ada, MN.  Read More
CropLife 100CHS, Aurora Cooperative Complete Fertilizer Storage, Grain Shuttle Loading Facility
April 13, 2015
CHS Inc., the nation’s leading cooperative and ranked No. 5 on the CropLife 100, and Aurora Cooperative (ranked No. 21) Read More
CropLife 100GROWMARK Acquires Missouri Refined Fuels Terminal
April 2, 2015
Bloomington, IL-based GROWMARK and Magellan Pipeline Co. have entered into an agreement in which GROWMARK will acquire the refined fuels Read More
Latest News
ManagementA New Sprayer Company & UAV Research In The Spotlig…
May 21, 2015
CropLife’s Paul Schrimpf and Eric Sfiligoj talk about a Dutch sprayer manufacturer entering the U.S. with a super-sized entry and Read More
HerbicidesFirst U.S. Sale Of Enlist Duo Herbicide Made By Dow Agr…
May 21, 2015
Dow AgroSciences has recorded the first U.S. sale of Enlist Duo herbicide with Colex-D Technology. This marks the first commercial Read More
CropLife 100The Andersons Acquires South Dakota Plant Nutrient Manu…
May 20, 2015
The Andersons, Inc., ranked No. 22 on the CropLife 100, has purchased Kay Flo Industries of North Sioux City, SD. “This Read More
EquipmentNORAC Options Coming To TerraGator
May 19, 2015
Utilizing NORAC’s Standard Control technology, boom height control is now available for TerraGators with Airmax Precision 2 and Benson Booms. This Read More
Crop InputsHelena Introduces New Soil Health Product
May 19, 2015
Helena Chemical Co. is helping agricultural producers maximize yields and efficiency with the introduction of Liquid Chisel, a new product Read More
Stewardship4R Nutrient Management Planning Certification Now Avail…
May 19, 2015
The American Society of Agronomy (ASA) and the International Certified Crop Adviser (ICCA) program announce a new specialty certification in Read More
Environmental Defense Fund logo
Paul SchrimpfEnvironmental Defense Fund: Appreciating Partners
May 19, 2015
I WAS deep in the throes of preparation for the Commodity Classic meeting that took place this past February, trying Read More
WebinarsUpcoming Webinars
May 19, 2015
Register for one of our upcoming Webinars or access our archive of past Webinars to view recordings of presentations that may be of interest to you. Read More
Syngenta Sign
Seed/BiotechSyngenta Responds To Lawyer’s Victory Claim In Vi…
May 18, 2015
A plaintiff’s lawyer has issued a public statement claiming that damages have been awarded in the Agrisure Viptera corn lawsuits Read More
StewardshipCould Australian Water Trading Approach Fit In Californ…
May 18, 2015
Ten years of drought isn’t a good thing. It doesn’t help the bottom line of farmers or the health of Read More
SpreadersDutch Sprayer Manufacturer To Enter U.S. Market
May 18, 2015
Dutch self-propelled sprayer manufacturer Agrifac Machinery has announced intentions to enter the U.S. market with two models of sprayers available Read More
FertilizerTFI Weighs In On Fertilizer Rail Transport Bill
May 14, 2015
With today’s House Committee on Transportation and Infrastructure as a backdrop, The Fertilizer Institute (TFI) registered its support for policies Read More
ManagementA Visit To The 2015 Environmental Respect Spirit Award …
May 14, 2015
CropLife’s Paul Schrimpf and Eric Sfiligoj talk about a recent visit to the CPS Spirit winner in St. Stephen’s Church, Read More
StewardshipBayer Entomologist Issues Statement On Annual Honeybee …
May 13, 2015
Richard (Dick) Rogers, Principal Scientist / Entomologist, Bayer Bee Care Center for Bayer CropScience LP, today issued the following statement Read More
Crop InputsKansas State Researchers Announce Resistant Kochia Brea…
May 13, 2015
Kansas State University researchers say new research helps explain why an invasive weed is developing resistance to a well-known herbicide, Read More
RR2X soybeans surround untreated check (center)
HerbicidesUSDA Study: Glyphosate Application More Prevalent In So…
May 13, 2015
Glyphosate—known by many trade names, including Roundup—has been the most widely used pesticide in the United States since 2001. It Read More
AdjuvantsHelena Chemical Introduces New Drift Control Adjuvant J…
May 13, 2015
Helena Chemical Co. introduces Justified, an innovative drift control agent designed to improve the performance and precision of spray applications Read More
CropLife 100North Central Farmers Elevator, Wheat Growers Unificati…
May 13, 2015
The Boards of Directors for North Central Farmers Elevator (NCFE) and Wheat Growers (WG) have voted to approve the Unification Read More