Storm Lake, Iowa — At a casual first glance, people may think that feedlot runoff should be less of a concern during drought conditions. After all, there’s very little rain, so there’s very little runoff. But an area expert says that feedlot runoff is of even MORE concern during dry weather.
Agricultural Engineer Kris Kohl with Iowa State University Extension and Outreach says that history has shown that drought years in late summer pose the highest risk of a runoff water quality violation.
He says the environmental standard for small Iowa feedlots is that a farmer settles out the settable solids before the runoff water leaves the property and that there is no water quality impairment. Under normal conditions, he says they focus on designing a system that will be capable of removing the solids without worrying about the second part. During droughts, the need to be able to keep all of the runoff on the farm property is more important, says Kohl.
He says unfortunately, there are other factors going on during a drought that could add up to disaster.
Kohl says high temperatures in water mean lower levels of oxygen available to fish before any feedlot runoff issues are even present. He says those same high temperatures are when the oxygen need is highest in fish.
Kohl tells us how small feedlot farmers can mitigate the risk.
He says that two free publications that can help are:
Inexpensive Pumping Systems to Manage Small Feedlot Runoff: http://www.iowabeefcenter.org/information/IBC52.pdf
Small Feedlot Runoff Management Using Low-Pressure Flood Irrigation: https://store.extension.iastate.edu/Product/14042
