Fall-Applied Phosphorus: Efficient And Effective

Is fall a good time to apply phosphorus, and will the applied phosphorus be available for spring-planted crops? Those are key questions many retailers and growers ask when considering fall-applied phosphorus.

This was the subject of CropLife Media Group’s recent Webinar “Fall-Applied Phosphorus: Efficient And Effective,” presented by Dr. Barney Gordon, agronomic consultant and Professor Emeritus, Kansas State Uni­versity, and Jake Sanders, Special­ty Fertilizer Products’ (SFP) vice president of market development. The two speakers discussed the advantages and benefits of fall phosphorus application, as well as some innovative tools that help increase its availability to spring-planted crops.

Maximizing Yields With Phosphorus

Phosphorus (P) is essential for crop growth and development, Gordon said during the Webinar. “Availability of adequate P, especially early in the growing season, has a profound effect on crop yield in both corn and wheat,” he said.

While application of P to the soil is necessary to ensure plant productivity, the recovery of applied P by the crop plants is often low due to a lack of P movement, or diffusion. Gordon said there are several factors that affect phosphorus diffusion in the soil. They are:

  • Volumetric water content: Increasing soil moisture level increases rate of diffusion.
  • Soil bulk density: Changing bulk density affects the ability of nutrients to diffuse to the root surface.
  • Soil buffering capacity: Ability of the soil to maintain nutrient concentration.
  • Nutrient concentration: Initial amounts of nutrients in the soil.
  • Temperature: Increasing the temperature increases concentration in the solution.

Studies show when soil temperature is reduced from 70°F to 58°F, corn root growth decreased five-fold and P uptake by corn roots decreased four-fold, Gordon said. “The colder the soil, the more problems we have getting phosphorus to the plant,” he said.

Gordon said he’s found little difference in yield when P was applied in the fall or the spring, providing growers with much-needed flexibility.

“Weather can cause delays in the spring, which makes it difficult to get planting done in a timely manner,” he said. “Fall application of fertilizer has the advantage of taking some of the workload off of producers. We could put our fertilizer on in the fall and still have it available and working for us in the spring.”

In addition to corn, wheat also tends to be highly responsive to P input, Gordon said. “P is generally the second most limiting nutrient in wheat production, behind N (nitrogen),” he said. “And in some areas, P is more limiting than N.”

Early-season P deficiency limits yield potential in wheat production, Gordon added. “The most critical period is that first five to six weeks after emergence in the fall,” he said. “P has major impacts on tillering and rooting. So it’s critical we have adequate amounts of phosphorus in the fall when the wheat crop first germinates and starts growing.”

Greater Efficiency With AVAIL

One of the most significant problems associated with P is that it is extremely inefficient, SFP’s Sanders said. “It becomes tied-up, or fixed to the soil,” he said. “This happens because phosphorus has a negative charge and other elements in the soil have a positive charge. When they are active in the soil, they come together like a magnet and severely limit the crop’s access to the nutrient.”

Research shows that 75% to 95% of applied P is lost during the season of application. “In the best-case scenario, we are losing 75% of our phosphorus, which is an incredibly inefficient way to do business,” Sanders said. “We firmly believe that a solution to that problem is AVAIL.”
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.
“Now instead of losing 75% to 95%, we keep a majority of that phosphorus available to the crop,” he said.

Sanders shared results from several corn yield studies that examined fall application of P with and without AVAIL. “We’re seeing the same positive effect whether we apply phosphorus with AVAIL in the fall or in the spring,” he said. “And when we’re talking about time savings, that’s a big deal. We can save a lot of time by getting that phosphate out early, protecting it, making it available to the crop and receiving the greatest return on investment for the grower.” 

Leave a Reply

Fertilizer Stories
FertilizerFall Fertility 2014: Forecasting Fertilizer Use
September 7, 2014
Great crops this year have tapped the soil, and fall work is definitely called for, but how challenging will that get? Read More
Aerial view of the West Fertilizer explosion site
FertilizerFertilizer Companies Blame City For West, TX, Explosion
August 6, 2014
El Dorado Chemical Co. and CF Industries contend the city failed to properly train the first responders and had insufficient protocols in place to battle the April 17, 2013, blaze at West Fertilizer Co. that triggered the explosion. Read More
FertilizerThe Fertilizer Institute: New President, Renewed Energy
February 3, 2014
Chris Jahn relishes the opportunity to lead the organization through the challenging times ahead. Read More
FertilizerA New Cycle For Fertilizer Demand
January 2, 2014
Changes in the corn market could have a major impact on the crop nutrients sector in 2014, say experts. Read More
Top 100 Articles
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
CropLife 100Wilbur-Ellis Acquires South Dakota Retailer
April 2, 2015
Wilbur-Ellis Co.’s Agribusiness Division, a recognized leader in precision agriculture technology and the distribution and marketing of plant protection, seed Read More
CropLife 100The McGregor Co. Closes Smith-Kem Acquisition
April 2, 2015
The McGregor Co. — ranked No. 16 on the CropLife 100 list of largest U.S. ag retailers — has completed Read More
CropLife 100BRANDT Commemorates National Ag Day
March 20, 2015
The Illinois agriculture community gathered at BRANDT global headquarters on March 18 to celebrate National Ag Day behind this year's theme Sustaining Future Generations. Read More
Latest News
ManagementMissouri Experts: Spring Planting Slow Start Won’…
April 20, 2015
In the first of the agronomy teleconferences with Extension specialists, University of Missouri Extension climatologist Pat Guinan said the slow Read More
Carl Casale of CHS
Industry NewsCooperative CHS Reports Net Income Of $471.5 Million Fo…
April 20, 2015
CHS Inc., the nation’s leading farmer-owned cooperative and a global energy, grains and foods company, has announced company net income Read More
Industry NewsCHS Insurance Names New Director Of Sales
April 17, 2015
Bryan Lewis has been named director of sales for CHS Insurance, the nation’s largest agribusiness insurance broker and full-service insurance Read More
Mature Waterhemp in Corn
HerbicidesGenetic Literacy Project: There’s No Such Thing A…
April 17, 2015
Read the latest “analysis” on GMOs from Consumer Reports and you’ll “learn” that glyphosate, the chemical developed by Monsanto (its Read More
HerbicidesNew Resistance To 2,4-D Discovered In Australia
April 17, 2015
In a world-first case of herbicide resistance, researchers have confirmed that sowthistle weed in the south east of South Australia Read More
ManagementNews From RTP Company Visits and Growers Buying Older S…
April 16, 2015
Paul Schrimpf and Eric Sfiligoj discuss recent trips to the Research Triangle Park area and market seed sales trends. Read More
soybean field
StewardshipNew ASABE Standard Establishes Framework For Sustainabl…
April 16, 2015
The American Society of Agricultural and Biological Engineers (ASABE) has initiated a project to develop a new standard to establish Read More
MicronutrientsSouthern States: An Inside Look At Our Tissue Sampling …
April 15, 2015
Remember learning about the food pyramid in school? The nutritional diagram recommends the proper amount of nutrients you need on Read More
Industry NewsArysta Adds New U.S. Fungicides Marketing Manager
April 15, 2015
Arysta LifeScience North America recently hired Deneen Sebastian as its Marketing Manager for U.S. Row Crops, Fungicides. Most recently, Sebastian Read More
FungicidesVerdesian Launches Phosphite-Based Cereal Fungicide
April 14, 2015
A new, phosphite-based fungicide designed for improved suppression of deoxynivalenol (DON) in wheat and barley infected by Fusarium head blight Read More
Mature Waterhemp in Corn
HerbicidesSURVEY: Close To 90% Of Growers Battle Weed Resistance
April 14, 2015
Herbicide resistance management continues to be a priority for corn and soybean growers, and they’re working together more effectively to 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
StewardshipFMC Corp. Joins Sustainable Agriculture Alliance
April 14, 2015
FMC Corp. has joined Field to Market: The Alliance for Sustainable Agriculture, a multi-stakeholder initiative working to define, measure and Read More
Industry NewsArysta Adds Two To Goëmar Sales Team
April 14, 2015
Arysta LifeScience North America recently announced two new additions to the Goëmar sales team: Steve Kelly, Technical Service Manager – Read More
Valley Variable Rate Irrigation
Precision AgVariable Rate Irrigation Gains Followers
April 14, 2015
Irrigation systems have had the ability to apply different amounts of water throughout a field for decades, using timers that Read More
CropLife 100CHS, Aurora Cooperative Complete Fertilizer Storage, Gr…
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
Soybean field
Industry NewsThree Ag Co-ops Poised For Possible Merger
April 13, 2015
Following months of study and preparations, the Board of Directors for United Farmers Coop (UFC), Farmers Elevator Cooperative (FEC) and Read More
Eric SfiligojAgriculture Braces For More Belt-Tightening
April 13, 2015
Spring is in full bloom across the U.S. and ag retailers and their grower-customers are busily getting into high gear. Read More