Dry weather and feedlot runoff
July 17, 2017 by Shawn Shouse ISU Extension Ag Engineer
July 17, 2017, Ames, IA – You might wonder what dry weather and feedlot runoff would have in common. On the one hand, the recent spell of hot, dry summer weather has caused expanding areas of moderate drought and excessively dry soils in Iowa and Nebraska. But this spell of dry conditions also makes for an excellent time to maintain your feedlot runoff control system.
Extended dry periods create the perfect opportunity to remove settled solids from your settling basin or other areas where manure solids collect during runoff events. Whether it’s a settling basin, a settling bench or terrace, or even the bottom end of feedlot pens, now is a great time to get out there with the loader, box scraper, or other equipment to remove those accumulated solids and dress up the area for the runoff that is sure to return. Land apply those solids if you have application areas available now, or stockpile them in a controlled area if they need to wait until after harvest for application. Make sure the stockpile area is either within the runoff control boundaries for your feedlot, or in an area that is protected from runoff and water flow when it rains. High and dry is the short description of a good stockpile location.
While you’re removing separated solids, be sure to check the liquid outlet from the settling area. If you’re using a picket dam or perforated riser to control the outflow, make sure the openings are clean and in good condition. Remember, the purpose of the controlled outlet is to hold liquid in the settling area until solids can settle, and then slowly drain the settled effluent off to an area where it can soak into the ground. Too much opening can let liquids through before solids can settle. Plugged openings can prevent dewatering and drying of the solids to a consistency you can handle.
While you’re tending to the settled solids removal, take the opportunity to evaluate the other parts of the system as well. Check the clean water diversion portions: rain gutters on buildings, clean water diversion terraces, and clean water tile drains. Then check your runoff controls beyond the settling area. If you pump your effluent to an application area, check the pump, controls and piping. If you let gravity do the work, follow the flow path down the hill from your settling area and see where it ends. If it ends on flat ground in a pasture, field, or treatment area, you’ll see a few more manure solids that settle and accumulate there, with no eroded gully beyond. If it ends in a waterway, ditch or stream, your manure could be causing negative impacts and putting your operation in regulatory and financial risk.
Assessment tools and advice are available in print, online, and from experts who can help. Check out the resource links on the Small Feedlot & Dairy Operations website or contact your industry representatives or an Iowa State University Extension dairy, beef, or engineering field specialist. Kits are even available from selected County ISU Extension offices to help you test water quality.
Managing manure runoff centers around more effectively collecting and storing manure, reducing the amount of clean water that mixes with manure, and capturing runoff so manure nutrients can be held and used as fertilizer. The good news is that each of these practices generates additional fertilizer value for your farm at the same time it lowers your risk exposure. So seize the opportunity to maintain your system and take some positive steps to put your manure where it pays.