Ask an Agronomist
How Do I Address Sulfur Needs In Corn?
Jun 03, 2011
Question: I'm very confused with everything you read about S needs, removal, uptake and recommendations. One expert says for 200-bushel corn, uptake is 30 lbs and removal is 15 lbs. I don’t understand why the numbers are so different. Another expert says that S removal is .07 pounds per bushel, which is close to agreement with the above statement. Do I need 15 or 30 pounds for 200-bushel corn?
Answer: Nutrient removal values are different that nutrient uptake values. Nutrient uptake refers to the total amount of nutrients accumulated in the crop biomass, some of which, depending on the crop, is recycled in the field. Nutrient removal values refer only to that fraction of the crop that is harvested and removed from the field. So, in other words, when residue is left in the field it contains nutrient value. Removal rates are typically based on pounds per bushel. As long as your cropping history has residue left in the field, you should be fine applying just removal rates of Sulfur. Keep in mind that your soil test can also give you an indication of residual levels of sulfur in your soil. For a 200 bu/A corn crop, consider applying 15 lb Sulfur per acre.
This farmer addressed sulfur losses in his corn crop.
A 2010 survey of alfalfa stands in Wisconsin lends still more credence to the notion that growers in parts of the country need to be on the lookout for signs of sulfur deficiency in their crops.