A man called seeking information about how my bee colonies have been doing for the last couple months. He works part time for the USDA and part of his job is to access honeybee colony losses from area beekeepers. He also wanted to know if there was a problem with the various bee parasites and diseases that are of concern as they can greatly interfere with the productivity and health of a colony. My hives are doing well and so the conversation quickly turned to other subjects.
He mentioned that where he lives in Northwestern Minnesota, they received twelve inches of rain in the month of June and another five inches during the first two weeks of July. He was rather startled to hear that this part of Minnesota has been experiencing a drought. There are reports of wheat in North Central Minnesota of getting only six or so inches tall and being fully ‘headed out’, in other words with fully formed kernels, that may be too short to harvest. But where this man lives crops are, in many cases, under water from the excess rain.
For more times than not, since April storm fronts sweeping in from the west in an arc from the Canadian border to Iowa have split apart near Northern Cass county. Friends call it the ‘Remer split’. Just about the time it looks like some significant moisture might arrive, the front ‘splits’. Part goes north and east and the other part goes south and east. A recent storm was the exception dropping nearly two inches in about an hour. Yet the ground was so hard and dry that a good deal of this moisture just ran off and didn’t soak in, causing road washouts but leaving hay fields high and dry.
So here’s a question to consider: On average where does the greatest water erosion to soil occur? Places where there is an abundance or at least a moderate amount of rain or where there is relatively little - as in semi-desert regions? Here’s one way to think about this. Imagine a field all plowed and disked all ready for planting. It is not completely flat and has small rises and lower areas, but no swamp. Now imagine a cloud burst drops two inches of rain in an hour. What are you going to see on the slopes? Because there are no plant roots to ‘hold’ the soil, there are going to be gullies from the quick flood of rain.
So unless there is no rainfall at all, the greatest erosion takes place where there are no, or few, plant roots to hold the soil in place. In Nature the greatest erosion takes place in normally dry regions that nonetheless occasionally get a lot of rain all at once. More than one person learned the hard way that a dry riverbed is a bad place to pitch a tent ‘out West’. A thunderstorm miles away can suddenly fill a gulley with water, mud, and debris and send a flood down stream engulfing the unsuspecting campers.
Human activities, particularly commercial monoculture, create vast areas without vegetation for a significant portion of the year, which become vulnerable to soil erosion. In effect we have increased by many fold the areas of high erosion that were formally found in semi-desert regions. This occurs wherever tilled ground has some relief, i.e. it is not flat. Because of the rapid run off, areas (like the Red River Valley) become susceptible to flooding, as the bee man mentioned.
Many years ago when he lived in southern Minnesota, a friend started a tiling business. Crop farmers hired him to put tile (pipe) underground to drain low areas to make them tillable. After ten years one particular farm had changed ownership a few times and the new occupants wanted the tile removed. He had placed the original tile underground about two feet so as not to be hit by plowing. Yet in one area he had to go down eight feet to reach the tile. The difference represents only ten years of eroded topsoil off the higher ground and washing down into the low areas.
Email Terry Mejdrich at email@example.com.