Foliar fertilizer applications to soybeans are rarely profitable

decrease font size  Resize text   increase font size       Printer-friendly version of this article Printer-friendly version of this article

There continues to be interest in applying foliar fertilizers to soybeans. This is true even though foliar fertilization has produced mixed results in hundreds of university trials conducted across the United States. This article summarizes the results from on-farm soybean foliar fertilizer trials conducted in Michigan over the past five years. The research was conducted by the Soybean Management and Research Technology (SMaRT) project, a partnership between Michigan State University Extension and the Michigan Soybean Promotion Committee

The effects of five foliar fertilizers (3-16-16, 3-18-18, 26-0-0, various boron carriers and manganese sulfate monohydrate) on soybean yields has been evaluated in on-farm replicated trials in Michigan. The 3-16-16 was evaluated at 27 locations and the 3-18-18 was evaluated at 24 locations in 2009 and 2010. Both products were applied at R1 and again at R3. All of the 3-16-16 applications also contained trace amounts of micronutrients and the second application of 3-16-16 contained sugar to improve nutrient uptake. The 3-16-16 and the 3-18-18 foliar fertilizer treatments were less profitable than the untreated control treatment when all locations were combined and analyzed.

The 26-0-0 foliar fertilizer was evaluated at 18 locations in 2011 and 2012. One gallon of 26-0-0 per acre was applied between R2 and R4. Again, when all 18 locations were combined and analyzed, the foliar fertilizer treatment was less profitable than the untreated control treatment.  

Various boron fertilizers were compared to an untreated control at six locations. The trials were conducted on potentially responsive sites and the boron was applied at 0.25 lb. of actual boron per acre at R1. The foliar boron treatments did not increase soybean yields compared to the untreated control.

Two trials evaluating the effects of manganese foliar fertilizer applications on soybean yields were conducted in 2013. The first trial compared manganese sulfate monohydrate fertilizer to a popular EDTA chelate manganese fertilizer at two highly responsive sites (muck soils). The manganese sulfate monohydrate increased soybean yields by 1.9 bushels per acre and income by 23 dollars per acre over the EDTA chelate. The second on-farm research trial evaluated the effect of applying a manganese foliar fertilizer to soybeans without visible manganese deficiency symptoms. This trial was conducted at two potentially responsive sites (lakebed soils with pH levels of 7.4). The trial results confirmed that manganese foliar fertilizer applications made in the absence of visible deficiency symptoms will not increase soybean yields. In fact, research conducted by the Ohio State University in 2008 and 2009 showed that foliar applications of manganese fertilizer in the absence of foliar deficiency symptoms actually reduced soybean yields.

Due to the low probability of realizing an economic return, applying foliar fertilizers to soybeans is not recommended by Michigan State University Extension. The exception to this is foliar applications of manganese fertilizer when manganese deficiency symptoms are visible. Please see the MSU Extension news article on identifying and correcting manganese deficiency in soybeans for more information.   

 This article was produced by the SMaRT project (Soybean Management and Research Technology). The SMaRT project was developed to help Michigan producers increase soybean yields and farm profitability. SMaRT is a partnership between MSU Extension and the Michigan Soybean Checkoff program.

Buyers Guide

Doyle Equipment Manufacturing Co.
Doyle Equipment Manufacturing prides themselves as being “The King of the Rotary’s” with their Direct Drive Rotary Blend Systems. With numerous setup possibilities and sizes, ranging from a  more...
A.J. Sackett Sons & Company
Sackett Blend Towers feature the H.I.M, High Intensity Mixer, the next generation of blending and coating technology which supports Precision Fertilizer Blending®. Its unique design allows  more...
R&R Manufacturing Inc.
The R&R Minuteman Blend System is the original proven performer. Fast, precise blending with a compact foot print. Significantly lower horsepower requirement. Low inload height with large  more...
Junge Control Inc.
Junge Control Inc. creates state-of-the-art product blending and measuring solutions that allow you to totally maximize operating efficiency with amazing accuracy and repeatability, superior  more...
Yargus Manufacturing
The flagship blending system for the Layco product line is the fully automated Layco DW System™. The advanced technology of the Layco DW (Declining Weight) system results in a blending  more...
Yargus Manufacturing
The LAYCOTE™ Automated Coating System provides a new level of coating accuracy for a stand-alone coating system or for coating (impregnating) in an automated blending system. The unique  more...
John Deere
The DN345 Drawn Dry Spreader can carry more than 12 tons of fertilizer and 17.5 tons of lime. Designed to operate at field speeds up to 20 MPH with full loads and the G4 spreader uniformly  more...
Force Unlimited
The Pro-Force is a multi-purpose spreader with a wider apron and steeper sides. Our Pro-Force has the most aggressive 30” spinner on the market, and is capable of spreading higher rates of  more...
BBI Spreaders
MagnaSpread 2 & MagnaSpread 3 — With BBI’s patented multi-bin technology, these spreaders operate multiple hoppers guided by independent, variable-rate technology. These models are built on  more...

Comments (0) Leave a comment 

e-Mail (required)


characters left

1325 Bushel Grain Cart

Equipped with a 22” computer balanced auger with 5/16” flighting,the unloading speed is 50% faster than smaller grain carts with ... Read More

View all Products in this segment

View All Buyers Guides

Feedback Form
Feedback Form