A Review of Manure Injection to Control Odor and Ammonia Emissions During the Land Application of Manure Slurries

Reprinted, with permission, from the proceedings of: Mitigating Air Emissions From Animal Feeding Operations Conference.

The proceedings, “Mitigating Air Emissions from Animal Feeding Operations”, with expanded versions of these summaries can be purchased through the Midwest Plan Service.

This Technology is Applicable To:

Species: Swine, Dairy, Beef
Use Area: Land Application
Technology Category: Management (manure injection/incorporation)
Air Mitigated Pollutants: Odor, Ammonia

System Summary

Manure slurry injection provides a significant reduction in land application odor and ammonia emissions release when compared to conventional manure surface broadcasting. Release of odor and ammonia during land application can be reduced by more than 90% compared to conventional application methods (Ohio State University, 2007). Manure can be successfully injected in both conventional tillage and no-till systems with currently available equipment. Additionally, slurry tanker wagons currently used for broadcast application can also be retrofitted with Injection tool bars.

Research by Hanna et al., (2000) compared the odor and ammonia emissions from various types of manure injection techniques to slurry that was surface applied (broadcasted). Odor and ammonia tests were run for both fall and spring slurry application. Ammonia was below the detection limit (0.2 ppm) for all but two (measured at 0.6 and 1.3 ppm) of the 72 samples taken. Broadcast application required approximately four to five times more fresh air dilutions than injection to reach the odor threshold (the level at which the odor can no longer be detected) indicating much lower odor release associated with injection.

Applicability and Mitigating Mechanism

  • Injection tools create sub-surface cavities
  • Slurry is injected into the cavity directly behind the tool
  • Injection minimizes slurry exposure to air reducing odor and ammonia volatilization
  • Injection can be used with all slurry and liquid manures


  • Injection systems are not currently commercially available for solid manures
  • Injection can require up to 30% more tractor horsepower than broadcast
  • Injection may not be desirable when the producer does not want the soil or crop root system disturbed (forages, pasture/sod)
  • Injection equipment requires more maintenance than broadcast equipment


Generally, injection is more costly than broadcast application. Injection requires more tractor horsepower and more equipment (injection tool bars). Because tool bars are pulled through the soil, wear and maintenance is greater with injection systems. Cost increases as application rate decreases and distance from the manure storage site increases. The increase in cost as application rate decreases is due to wear on the application equipment. At lower application rates, field speed is increased causing wear (and eventually maintenance) on the equipment to increase. At a 5,500 gallons per acre application rate, commercial drag hose injection cost is currently $.014/gal compared to $.0085/gal for broadcast (Puck, 2008).


Ross Muhlbauer1, Jeremy Puck2, Ben Puck2, Robert Burns1, 1Iowa State University, 2 Puck Custom Enterprises
Point of Contact:
Ross Muhlbauer, rmuhlbar@iastate.edu

The information provided here was developed for the conference Mitigating Air Emissions From Animal Feeding Operations Conference held in May 2008. To obtain updates, readers are encouraged to contact the author.