Do you know where your soil is tonight?
One of the rhetorical questions parents are occasionally asked is “do you know where your children are tonight?” This sentence is both questions and accuses since it assumes that at least some of those being questioned don’t know. I will admit it’s a stretch, but a similar question may be asked about soil following the extended periods of wet weather and stream flooding we are experiencing this year.
Some of the most discouraging situations I have seen during my career have been those in which soil has been removed from fields all the way down to the layer of relative compaction by water flowing over recently tilled fields. When this happens we can see the evidence of past tillage operations, especially when the field was recently subsoiled. In some cases old rows that were obviously not created with modern equipment can be seen. Sometimes even the mule tracks are there to remind us of a bygone age.
When this happens we know that essentially all of the disturbed soil above the layer of compaction has been carried away by rapidly flowing water. People used to call these intensive rainfall events “gully-washers” and this is a fairly accurate term. One situation I read about recently was from the intensive flooding that occurred last year in Missouri in which the furrows made as much as a century earlier were revealed, and the remnants of horse-drawn farm implements were found in fields of that area when emergency flood gates were opened.
I have seen similar situations along some of our major streams. Farmers have experienced the result of recent tillage operations on their fields as the topsoil they had farmed for decades was no longer in place but downstream somewhere. There is really no way to repair this kind of damage to fields even though some have tried hauling in new soil. Topsoil is special stuff and can’t be found just lying around for us to use in making repairs. About all that is accomplished by moving topsoil is to ruin one area to make what will likely be a temporary repair to another. In many cases these fields will not recover their productivity.
The question then is how to avoid this kind of catastrophic soil loss. The answer is that the soil should not be disturbed in these fields prior to our most likely periods of heavy rainfall. Cover crops with abundant roots will help hold soil in place, and diversions can be constructed to divert current away from open fields. Ideally, a combination of measures should be employed to reduce the chance for this devastating form of soil erosion.
As I am writing today the sun is shining, but another period of rain is predicted. We seldom think of issues like this until it’s too late. This seems to be the kind of thing we fail to expect even though it happens somewhere almost every time we have a major rainfall event. We must begin to plan for protection of our land against soil loss in all its forms, but especially this devastating kind that causes catastrophic and irreversible damage to our ability to produce.
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