Wind erosion does environmental, economic damage
WILLMAR, Minn. -- Snow and dirt — known as “snirt’’ — covered fields of west-central Minnesota this winter have served to call attention to the problem of wind erosion.
All that snirt certainly caught the eye of Jodi Dejong-Hughes, whose role with the University of Minnesota Extension is all about soil health. She is an agronomist with a master’s degree focused on soil fertility.
Instead of attempting to prick the conscience of those who allow what she calls the region’s most valuable, natural resource to blow away, Dejong-Hughes takes a different approach.
She points out that wind erosion is also picking the pocketbooks of those who allow excessive wind erosion to occur.
In one case, she found that the snirt coming from a tilled field in the middle of Chippewa County represented the loss of $96.20 worth of nutrients per acre.
Dejong-Hughes often drives Minnesota Highway 40 in Chippewa County, and that’s where the snirt’ produced by the tilled field came under her scientific scrutiny.
Speaking March 7 at the Hawk Creek Watershed annual meeting in Willmar, DeJong-Hughes explained that she took samples of snirt from the top inch of snow and had it analyzed for total NKP, or nitrogen, potassium and phosphorus.
The results showed that on a per acre basis, the field was losing $64.90 worth of nitrogen, $23.50 of potassium and $7.80 of phosphorus, a total loss of $96.20.
Even those numbers don’t tell the whole story. The snirt was not analyzed for the many valuable plant minerals it also contained and lost to the field.
And, DeJong-Hughes pointed out that snirt is very dark, evidence that it also has a high organic content. The loss of the organic matter can also translate to reduced yields.
The soil carried by the winter winds does not end up in Wisconsin or other points east or south. It ends up in our waterways where it adds sediment and nutrients that degrade water quality.
But as DeJong-Hughes pointed out, it’s not just the environmental damage that matters. The economic losses are huge, too.
DeJong-Hughes said we can reduce our losses to wind erosion by leaving at least 30 percent of the crop residue in our fields, reducing our tillage, and taking advantage of wind breaks.
Unfortunately, she’s seen too many wind breaks felled as corn prices rose in recent years. She also bemoans the fact that implement manufacturer John Deere reports that the last few years saw some of its highest mold board plow sales.
Minnesota has some of the most productive soils in the world, but she expressed concerns that we do not appreciate what we have. Farmers in other states keep more crop residue in their fields, she pointed out.
She’s taken advantage of her travels on Highway 40 this year to take lots of photos of the fields that look like giant platters of chocolate ice cream with swirls of marshmallow.
“And I didn’t know what snirt was until I moved to Minnesota,’’ she said.