Experts estimate this past week’s heavy rains pushed thousands of tons of top soil off Iowa farm fields. According to an Iowa State University analysis, farm field flooding occurred in parts of 22 Iowa counties and the average soil loss per acre was seven tons.
Jim Ayen of the USDA’s Natural Resources Conservation Service recommends that farmers check their water-logged fields. "Check areas that have ponding to make sure that surface inlets, tile inlets, are not plugged with corn stalks that have floated around…just to make sure that everything is working properly there in the drainage system," Ayen says.
There may be a silver-lining in the flooding, according to Ayen, as it will give farmers a very accurate, real-time example of where conservation measures may be needed most in their fields. "Rain storm events like we’ve had the last week is an opportunity for producers to take a look at their land and see where erosion problems have occurred," Ayen says. In those problem areas, farmers might consider constructing terraces to stop soil erosion or even expand so-called buffer strips where grass is planted as a barrier, keeping top soil from flowing into a nearby waterway. Ayers says expanding underground tiling systems in a farm field may be the answer in some limited instances.
"They need to be really careful that they’re not considering tiling anything that could be classified as a wetland or a farmed wetland," Ayen says. "That could be a potential to getting the producer in violation of wetland compliance rules with USDA."
Ayen cautions against an over-reaction when it comes to farm field flooding. "Producers need to realize that we have some extreme weather events, so think of the average not of the extreme in looking at problems," Ayen counsels. "On the other hand, don’t overlook those areas that really need to get some treatment."