By Mark Bredehoeft*
Application of an in-furrow 10-34-0 starter fertilizer at planting is generally considered to be a paying proposition in the Red River Valley and southern Minnesota sugarbeet areas. Often-cited benefits include increased early season vigor, improved crop stress tolerance, a typical boost in final recoverable sugar per acre, and optimal use of applied phosphorus inputs.
A four-year research project in the Southern Minnesota Beet Sugar Cooperative district looked at potential benefits derived by adding various “pop-up” products to a 10-34-0 starter fertilizer. The tests — carried out at three locations in 2008 (Wood Lake, Clara City and Hector) two in 2009 (Clara City and Hector), two in 2010 (Bird Island and Maynard) and at one location in 2011 (Cosmos) — evaluated various products to determine whether any of them would, alone or in combination with 10-34-0, further boost productivity.
Three products were tested all four years:
• Soygreen®, a dry water soluble powder 6% Iron ORTHO-ORTHO EDDHA chelate.
• Man-Gro DF, a highly concentrated water-soluble manganese powder designed for foliar application. It is designed to combat glyphosate-induced manganese deficiency.
• Boron, applied using Tetra-Bor 10, a product that contains 10% boron as well as some macronutrients.
Another product was tested three years (2009-11): Redline™, which contains many nutrients required for plant growth, as well as the same technology used in Soygreen. (A 3.0-gal application of Redline provides 1.0 lb of Soygreen.)
EB Mix®, a product containing a blend of nitrogen, sulfur, boron, iron, manganese and zinc, was tested in 2010 2011 along with the above products.
The 2011 test included all of the above products, plus:
• Riser®, which is 7-17-3 with micronutrients and ACA® technology.
• Radiate®, which contains two different plant growth regulators.
• Nachurs 6-24-6.
Because of the one- and two-year nature of some products’ testing, those product results are not reported here. Table 1 shows three-year combined results (2009-11), while Table 2 presents the four-year results (2008-11).
The combined data from 2009 through 2011 show all those treatments to be statistically significant when compared to the untreated plot. Using any of those in-furrow treatments should increase production. Redline and Soygreen + 10-34-0 produced a revenue percent of mean that was greater than standard 10-34-0.
The data covering 2008 through 2011 (Table 2) indicate no significant difference among that group of in-furrow products. There was a trend, however, for Soygreen at 1.0 lb/ac and Man-Gro at 3.0 lbs/ac to be beneficial.
Overall, the four years of product tests showed that the inclusion of pop-up fertilizer was beneficial to sugarbeet production — and, the combination of Soygreen and pop-up fertilizer significantly increased production.
Future work should include investigation of in-furrow products with a “holistic” nutrient approach. The interest in a holistic approach is a result of research that has demonstrated the advantages of fertilizer products applied individually or in a package. Such research should evaluate methods, rates and timing of application in order to provide the most benefit.
* Mark Bredehoeft is research agronomist with Southern Minnesota Beet Sugar Cooperative, Renville.
Editor & General Manager of The Sugarbeet Grower