Corn School: Unleashing the power of potash


When it comes to corn fertility and higher yield, nitrogen is the star of the corn production show. But Carleton Place, Ont., farmer Mark Foster and agronomist Paul Sullivan feel it’s time potash received its share of the spotlight.

At the SouthWest Agricultural Conference earlier this month, the pair shared how they have unleashed the power of potash (K) on a farm Foster and his partners at JockBrae Farms purchased five years ago. On this episode of the RealAgriculture Corn School, Sullivan, who operates Kinburn-based P.T. Sullivan Agro consulting, is quick to point out that potash is just as important as nitrogen when it comes to corn production: “If it’s missing that potash, it’s having a bad day.”

In the video, Foster explains that soil tests at the new farm identified potash deficiency as a limiting factor. He then set out to restore soil potash to base levels. “We looked at it as a capital investment in the land,” he says, noting that potash was applied at a variable rate in 2019 because not every acre will provide a return on a potash investment. He estimates that every $100 of additional potash input per acre will yield a net return of $30 per acre. It also builds baseline fertility levels that will pay dividends annually going forward.

Foster says he was expecting to see the first big payback in 2019. Typically, he counts 16 rounds on his corn cobs but this year cobs added an additional two rounds, equivalent to an extra 20 bushel yield potential. Going into the late summer Foster estimates he would have harvested his biggest ever corn crop but Mother Nature took it away as difficult growing and harvest conditions prevailed in the region.

In the interview Sullivan also discusses the potash application regime, including the importance of adding 20 pounds of seed-placed starter K.

Click here for more Corn School episodes.

Editor’s note: There are two towns named Kinburn in Ontario. Sullivan hales from the one west of Ottawa. Yes, Lyndsey Smith is nearly his neighbour. It’s a great little town. 

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Corn School (view all)Season 9 (2020) Episode 30

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