Use ISU Extension and Outreach Publications to Make Informed Manure Decisions

Resources help farmers understand how to use manure in their operation


tractor with manure tank and injectors in fieldAMES, Iowa – Harvest has arrived, and with it manure application season has begun. Iowa State University Extension and Outreach has resources available to help farmers make informed decisions about manure application this fall.

Manure can be a valuable commodity on a farm, and ISU Extension and Outreach publication “Manure: A Valuable Commodity” (AE 3607) looks at the value of manure and how its characteristics have changed.

“The first step to understanding how to get the most from manure is to collect a sample,” said Dan Andersen, assistant professor and extension agricultural engineering specialist at Iowa State University. “Believe me, this is worth your time and effort as manure offers a potential value of around $8 an acre.”

The steps for analyzing manure can be found in ISU Extension and Outreach publication “How to Sample Manure for Nutrient Analysis” (PM 1558). Two additional resources to help farmers make better manure application decisions after sampling are “How to Interpret your Manure Nutrient Analysis” (PM 3014) and “Using Manure Nutrients for Crop Production” (PMR 1003).OK

After determining how to apply manure, the final step is to get the manure into the ground.

“The biggest things to think about are the timing of application, method of application and making sure you are getting the most from your equipment,” Andersen said. “Regarding equipment, there are two things to check – making sure we are hitting the rate we want and then making sure the application is as uniform as possible.”

ISU Extension and Outreach publications “Calibrating Liquid Tank Manure Applicators” (AE 3601A) and “Distribution of Liquid Manure Application” (AE 3600) provide information on how to set up and monitor the amount of manure applicators are spreading.

The timing of manure application is also important. Delaying application until the soil temperature is less than 50 degrees F and cooling helps to ensure nitrogen will be there next year for crops to use. Anderson’s blog, The Manure Scoop, details the science behind the recommendation. Insuring this temperature recommendation is met is more important on ammonium-rich manures like liquid swine manure where the nitrogen is more readily available.

Much more information about the use of manure is available through The Manure Scoop, which is updated throughout the year.