The choice to apply start-up fertilizers – the appetizer in a corn crop’s nutrient meal – comes down to three options: orthophosphates (orthos), polyphosphates (polys), or a combination of the two.
Federated stocks a 100% ortho 6-24-6 start-up fertilizer, and XLR-rate™ , which is 80% ortho and 20% poly, as good sources of in-furrow phosphorous that are very seed safe and have a low use rate of 3-5 gal./ac. Craig Loen, Federated agronomist at the Osceola location, noted that plants take up phosphorous in the orthophosphate form – and they require moisture, proper pH, and the right soil temperature to work well.
“Orthos work better in-furrow,” said Loen. “Polys can be used in furrow and two-by-two placement, but they aren’t seed safe; they require low use rates and more moisture in the soil. Their salt content is higher and can cause seed burn, which reduces germination.”
Loen said, “If it’s a dry spring and it’s warm, [the polyphosphates] will try to suck the moisture from the seed” and kill the germ.
Federated carries a very common polyphosphate, 10-34-0, which is 60-65% poly and 35% ortho. Polyphosphates are higher in nutrient content and in two-by-two situations can be applied at a rate of up to 15 gal./ac.
Under ideal conditions, both orthos and polys will work well; environmental conditions, equipment availability, and cost are often the deciding factors.
Federated can also create custom blends with either polys or orthos, depending on crop and field needs, with 10-34-0 UAN and ammonium thiosulfate. These blends bring home the nutrient meal analogy: “You are putting out more groceries for your crop,” said Loen, “in the close band to the seed.”
Talk to your Federated Agronomist soon to determine the perfect “meal options” for your 2018 crops.