NDSU’s K Level Update: A Key Profit Boost for Midwest Soils
The term “smectite” probably isn’t something most growers have heard before. It’s a mineral commonly found in soils throughout North Dakota and the Midwest. According to a groundbreaking NDSU study, it may also be one of the biggest factors impeding potassium availability — and grower profitability. That’s because by their very nature, smectites “hold” potassium. Dr. Dave Franzen and his team determined that in order to account for the impact of these minerals, the potassium critical level should be raised from 150ppm to 200ppm in highly smectitic soils. This change may help a third of the state’s corn-growing region earn tens of thousands more each year. And may help many across the Midwest do the same.
Majority of funding for research provided by the North Dakota Corn Council.
A new critical level
Research shows if your soil has a 3.5 or greater smectite-to-illite ratio, and you have a soil test less than 200ppm, you’ll get an economic return from the addition of potash.
Smectite-to-illite ratios
Highly smectitic soils make up a third of North Dakota’s corn-growing region and constitute hundreds of thousands of acres across the Midwest.
