For those of you who have read my column in the past, you may recall last winter that I wrote about all the fall tillage after a very nice harvest. The weather had been so good that farmers had a lot of time on their hands, so they plowed … and chiseled … and disked!
I indicated that this addiction to tillage was not good for you – or your soil. Following last week’s four- to five-inch goose-drowning rains, I’m seeing much evidence of the harmful effects of that “tillage two-step.” There was a lot of soil erosion where the soil was not covered.
In the late ’80s, while participating in a national study tour as part of an Ohio Ag leadership program, I was tasked with the assignment to interview the USDA chief of the Natural Resources Conservation Service (then the Soil Conservation Service). Already aware of this Texan and his good ol’ boy approach to policy setting and American agriculture, I walked in braced for a showdown. He did not disappoint me.
We talked about the role of USDA in promoting more no-till and cover crops. I told him I was frustrated that USDA and the state and local partnership wasn’t doing enough to assist farmers in adopting these tremendous conservation practices. He asked what the average soil loss was for the farmland in Knox County, where I worked at the time. When I indicated the loss was four tons per acre per year, he replied, and I quote, “Ah, hell, son … what are you concerned about? Unless they’re (farmers) losing more than 10 tons per acre, I don’t get concerned.” Needless to say, losing that much soil year in and year out is not healthy or sustainable.
There are three types of erosion – sheet, rill and gully. While sheet erosion is generally not visible to the naked eye, losses can easily exceed four to five tons per acre per year. Sheet erosion is more common on short slopes, where the speed and carrying capacity of the runoff water is not as great as on longer, steeper slopes. The major “symptom” of sheet erosion is a deposit of sediment at the base of a slope.
Rill erosion develops when runoff water begins to cut definite channels or rills. Rills become wider and deeper as the velocity of runoff increases. This type of erosion is responsible for large amounts of soil loss and, thus, for serious reduction in productivity. Since the rills are only a few inches deep, they can be obliterated and go unnoticed when tillage occurs.
If erosion is not controlled, rills grow to gullies. A gully is large enough that it cannot be masked by normal tillage operations and it interferes with the movement of farm implements. Tremendous losses of topsoil and subsoil can occur as gullies develop, resulting in severe productivity losses.
The central focus of protecting your soil should be to build soil health. Thus it is vitally important to reduce the loss of topsoil as much as possible. We can never completely eliminate the loss of topsoil; however, we can build our soil health and replenish the losses by using conservation practices, such as no-till farming and cover crops that create a composting effect in the top few inches of topsoil, and grass waterways which gently “walk” the high-volume rainfall off the land in concentrated areas (eliminating gully erosion).
On my travels around the county last week, I did notice that where the farm had grassed waterways and crops planted by no-till, the water was flowing to the streams with virtually no harm to the land, thus protecting our water quality.
If you think you are experiencing too much erosion and could use some help with conservation needs on your land, call the Delaware Soil and Water Conservation and the USDA Natural Resource Conservation Service at 740-368-1921. We are here to help you help the land.
Brad Ross is communications specialist at the Delaware Soil and Water Conservation District. He can be reached at firstname.lastname@example.org.