From the Farm: Fertilizer Application


CENTRAL ILLINOIS (WCIA) – Record high prices for fertilizer are troubling many farmers in how much fertilizer should really be applied for the 2022 corn and soybean crops. But one person has an idea to consider.

Chief agronomist Howard Brown for Illini FS suggests that potash and phosphate for next year at least should be applied based on what was removed by the crop this year. His suggestion is based on the research of University of Illinois Crop Sciences professor Emmerson Nafziger.

“The University of Illinois back in 2017, Emerson Nafziger, generated the new numbers for removal; removal is the nutrients per bushel,” Brown said. “If I could just guess at it, I think .37 per bushel for P2O5 and .24 per bushel for K2O.”

What do we do with the yield and Emmerson’s numbers?

“The way I am looking at this is not looking forward anymore, it’s looking backward, and for example, this cornfield, this farmer had recorded yield with GPS and putting it on a file, and we know by position what it yielded,” Brown said. “And what we do is calculate with those removal numbers, plus what that crop took off, generate a variable rate removal map and put the fertilizer on that he removed from this crop. Not going forward, going backwards.”

Brown says this is going to be sufficient for next year when the farmer plants beans.

“Historically farmers have been using VRT based on the soil test and there are places in the field where they don’t even put on fertilizer,” Brown said. “I am saying that got us to where we’re at, but I am not saying that is going to get the Progressive farmers to where they want to go. They need to put fertilizer on every acre and they need to put fertilizer on, based off removal. There are places in this field this farmer got 360 bushels to the acre in some spots. He’ll never put that on unless he bases his fertilizer application on what he took off.”

“I am not saying that I’ve got all the answers, but if a farmer sits down and thinks about what I’ve said, it makes sense,” Brown continued. “And as we go forward, I would dare think, basing your nutrient applications on removal, soil tests won’t go down. They will eventually go up.”

Howard Brown will visit Midwest Ag This Week to talk about 2022 cropping plans. The show airs on WCIA3 Saturday and on X49 Sunday. Be sure to tune in.

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