IMMAG Updates

July 2017

Welcome to the monthly update for the Iowa Manure Management Action Group (IMMAG) Web site. This update is provided as a service to inform you about changes made to the IMMAG Web Page or items of interest dealing with manure management and air quality from animal feeding operations. If you wish to subscribe to this mailing please click here. You may also view this update with direct links on the CURRENT NEWS site on IMMAG.

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Dry weather and feedlot runoff

Shawn Shouse, ISU Extension Ag Engineer, 712-769-2650,

jersey cowsYou 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 resource links on the Small Feedlot & Dairy Operations website or contact your industry representatives or an ISU 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!

Maintaining Your Manure System

jersey cowsSummer is here and it’s brought dry weather throughout much of the state. This type of weather is a great time to check over your manure management systems and make sure it will keep doing its job. A great place to start is with your manure storage. Fall application season is still a ways away, but a little planning now can make sure you have the flexibility to manage your manure like the fertilizer resource it is, and to make sure your storage will keep functioning for years to come.
Proper management and maintenance is necessary to prevent manure from overflowing or discharging from a storage system. Whether the manure storage is in an earthen tank, a slurry store, or a deep pit, the basic principles to maintaining and managing the storage structure are similar. In any case, frequent evaluation and preventative maintenance will significantly reduce your risk and keep your manure where you want it.

  1. Monitor the operating level of your manure storages. Have a staff gauge or a method for determining how much manure is already in your storage. Keeping track of how much manure is there can give insight into if you have enough capacity to make it to your next land application window.  If you are worried you may run short this will give you an early opportunity to evaluate how you are going to handle the situation when your storage gets full. Monitoring the level can also alert you to if anything unexpected is occurring, for instance, your manure storage isn’t filling up or filling up really quickly because of a water leak or outside drainage water getting in.
  2. Visual structure inspection. A quick look over the storage can tell you a lot about how your structure is holding up - as you walk around pay close attention to inlet points, connections, and where the sidewalls connect to the base. To make this easier make sure you are mowing around your storage and cutting down trees, watching for animal burrows, and making sure clean water is being diverted around your manure storage structure.
  3. Odor evaluation. I know odor can be a stink of a topic, but it’s something we have to deal with. Make it a part of your routine to go around your farm once a week and make a note of the odor intensity and what neighbors may be smelling. Unfortunately there usually are not easy fixes, but for those of you interested in learning more about potential odor options check out AMPAT.
  4. Safety check. We all recognize there are some safety challenges to working in and around manure storage systems. Take the time to review your safety protocols and update as needed. Taking the time to go over them will remind everyone that they are important and there to protect us. While you are at it make sure to check any fences, escape ladders, and warning signs you have posted to make sure they are still in good shape, readable, and present.
  5. Clean water diversions. Minimizing outside water entering a manure storage helps keep nutrient concentrations higher making it an economic fertilizer for a farm to use. Check over the clean water diversions around your farm to make sure things like silage piles, mortality compost piles, and in-ground manure storage piles aren’t receiving water from other areas.
  6. Application equipment. Manure equipment lives a tough life, it gets used quick for a month and then put away. Take the time to check it over now before you need it again this fall and get that one last part that you’ve been meaning to fix.

Manure Scoop

We’ve all heard if a little is good then a little more must be better. Well, one Brown Swiss calf and a case of the scours from just a little too much milk taught me maybe that wasn’t always the case.  When it comes to manure nitrogen management, I still run into people who say I just don’t know what’s in the manure so I’ll put just a little extra on, you know a little insurance nitrogen. In this Manure Scoop I take a look at this practice and ask the question, is this really how we maximize profit? Take a look and see what I found.

Biofilters: An Option for Odor Control

For mechanically ventilated buildings, biofilters can be used as an effective odor control method. Using a bed of biological material, usually wood chips, ventilation air flows through the material. Moisture content must be monitored; by maintaining a moisture content of greater than 40%, cultures of microbes develop and absorb gases. Biofilters do require maintenance; air leaks and rodent control are two critical management issues. More information about biofilters can be found on the AMPAT website.

Manure Impact on Soil Aggregation

The most recent Manure and Soil Health (MaSH) blog explores how the formation of larger and more stable soil aggregates in field fertilized by manure may result in benefits including reduced runoff and soil erosion. Read the entire article here.


July 26, 2017 - Manure Distribution and Calibration Field Day, Zoske’s Sales and Service, Iowa Falls

August 4, 2017 - Manure Distribution and Calibration Field Day, Eldon C. Stutsman, Inc., Hills

August 22-23, 2017 - North American Manure Expo, Arlington, WI


Dan Andersen
(515) 294-4210
Twitter: @DrManure

Rachel Kennedy
(515) 294-6685

Melissa McEnany
(515) 294-9075


Iowa Manure Management Action Group
Twitter: @iowamanure

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