7/30/2019 Best Managemetn Practices for Reducing Ammonia Emissions: Manure Application

http://slidepdf.com/reader/full/best-managemetn-practices-for-reducing-ammonia-emissions-manure-application 1/3

 Fact Sheet No. 1.631D Livestock Ser ies|Management

©Colorado State University

Extension. 12/12.

www.ext.colostate.edu

by S.G. Lupis, J.G. Davis, and N. Embertson*

Ammonia volatilization rates ollowingland application o manure are inuencedby the method o application, weatherconditions, and time o year. In thisactsheet, we review application methodsthat can reduce volatilization ollowing landapplication o animal manure, and practicesor identiying and targeting weather and soilconditions that result in reduced ammonia

 volatilization rates.

Solid Manure

Solid manure is produced on drylots(both eedyards and dairies) and is oencollected by scraping it rom the pen surace.Manure collected rom dairy reestalls canthen be added to solid manure piles orallowed to dry. Te most eective method orreducing ammonia emissions rom manureapplication sites is to incorporate that manureinto soil as quickly as possible. Tis drastically 

reduces volatilization losses resulting romexposure to air. Immediate incorporationo surace-applied manure (within 1 hour)can reduce ammonia loss by 85-90%. Evenachieving incorporation within 24 hours has

 value. Te depth o incorporation can beas shallow as 2-4 inches to achieve good Nconservation.

Te primary challenge to incorporatingmanure quickly is timing; both theavailability o labor and equipment andgrowth stage o the crop. Since ammonialosses have the greatest potential to

negatively impact mountain ecosystemsin the springtime, it is most important toprioritize immediate incorporation or spring

Quick Facts

• Application of animal manure

tocropfeldsisapotential

source of ammonia (NH3)

emissions from agriculture.

•Volatilization of ammonia

from land-applied manure is

a loss of valuable nitrogen,and can contribute to air

quality concerns because NH3 

contributes to the formation

of particulate matter, which

can be hazardous to human

health and degrade sensitive

ecosystems.

•Targeting weather and soil

conditions may be more cost

effective for producers, as it

avoids purchasing or hiring

new equipment.

*S.G. Lupis, Institute for Livestock and the Environment,

coordinator; J.G. Davis, Colorado State University,

 professor, soil and crop sciences; N. Embertson,

Whatcom Conservation District in Lyndon, Washington,

 nutrient management and air quality specialist. 12/12

Best Management Practices for Reducing Ammonia Emissions:Manure Application

applications. In addition, timing applicationand rapid incorporation to take place duringrelatively cool, calm weather can also helpminimize ammonia losses. For example,applications in the evening, at night, and inthe early morning have been shown to reduceemissions by 50% compared with spreadingduring the middle o the day.

In general, applying compost to land will

result in lower NH3 emissions than applyingraw manure because NH3

has already beenlost during the composting process, andthere is very little ammonium le in thecompost i it is properly nished. It is lessimportant to incorporate compost into thesoil and, thereore, compost can be used as atopdressing on perennial crops such as grasshay or alala.

Manure Slurry 

Slurry manure may be produced on

dairies that use a vacuum system or manurecollection. Below, we describe a variety o application options or incorporating manureslurry into soil; however, o the optionsbelow, injection is the most efcient andeective means to reducing ammonia lossrom slurry manure applications to land.

Broadcast application o liquid manureslurry has the highest rates o airbornenitrogen loss because there is greaterexposure o the manure to wind and sun/heat, which increases ammonia volatilizationpotential. During broadcast application,

liquid manure is spread using a ‘honey wagon’ or surace broadcaster with a splashplate applicator, distributing manure on thesurace o the soil. While this method is quick and inexpensive, it tends to result in unevendistribution o manure (and subsequentuneven crop response), may damagegrass swards, can contaminate standingplants with microorganisms that can hurt

7/30/2019 Best Managemetn Practices for Reducing Ammonia Emissions: Manure Application

http://slidepdf.com/reader/full/best-managemetn-practices-for-reducing-ammonia-emissions-manure-application 2/3

silage ermentation, and may be prone

to runo into nearby waterways undercertain conditions. Rapidly incorporatingmanure aer broadcast applicationreduces ammonia losses, but increases thecosts associated with application. Surfacebanding using drop hoses or a ‘sleighoot’applicator deposits liquid manure underthe vegetation at the soil surace, increasingcontact with and incorporating it into thesoil. Standing vegetation provides shade,reduces wind speeds at the surace, andmay reduce volatilization loss. Suracebanding can increase nitrogen availability 

and reduce ammonia emissions by upto 80%, compared to traditional suracebroadcasting.

Shallow injection conserves morenitrogen than surace broadcast application(by 90% or more in one study) becausemore nitrogen comes into contact withand inltrates into the soil, reducingcontact with the air, and thereore reducing

 volatilization potential. Manure slurry injection works well in both conventionaland no-till systems with currently availableequipment. In addition, slurry tankerwagons currently used or broadcasting canbe retrotted with injection tool bars.

Shallow injection and surace bandingseem to be equally eective at reducingemissions compared to broadcastapplication. Where shallow injection may not be practical on stony soils, sloped land,or or producers with inadequate tractorhorsepower, surace banding may be abetter method.

It’s very important than the slurry application rate is not too high because i the slurry cannot quickly inltrate into thesoil and puddles in the injector urrows(just like over-irrigating) the eectivenesso the injection in N conservation will belimited.

Deep injection prevents exposure o manure to the environmental conditions

that cause ammonia volatilization whileimproving incorporation o manure intothe soil. o be most eective, the rate o manure applied should not exceed thecapacity o the injection slit, as slit closingis essential. Soil conditions and equipmentdesign play an important role in theeectiveness o deep injection application.Soils that are saturated or compactedcan hinder slit closing and interere withinjector unction.

Injection is more costly than broadcastapplication due to the higher horsepower

requirements (up to 30% more), additionalequipment needed (injection tool bars), andhigher maintenance costs, but it remainsthe most eective method or reducingammonia loss, thereby improving nitrogenavailability to plants.

Liquid Manure

Liquid manure may be produced ondairies that use a ush system or manurecollection rom reestalls or on eedlots thatirrigate their runo water onto neighboring

elds. Since liquid manure is 98-99% water,it is usually applied through sprinklerirrigation systems.

Fertigation with liquid manure can bean efcient way to deliver N to the crop i the application timing is planned to meetcrop N needs. In addition, the water itsel serves as a means to incorporate the Nbelow the soil surace i ¾ inch or more o water is applied at any one time. urningo the end gun o a center pivot and usingdrop nozzles can be helpul to minimizeNH

3loss during an irrigation event.

Other Considerations

Timing manure application can helpreduce ammonia volatilization and retainnitrogen. Nitrogen loss can be minimizedby avoiding application on warm, windy days or when weather conditions areorecast to be sunny and dry. In one study,emissions were reduced by 10% when

manure was applied during 54° F and 75%relative humidity conditions compared to59° F and 60% relative humidity. Althoughit is not always easible to wait or idealenvironmental conditions, application soonbeore a light rain on a cool, cloudy day, orin the early morning or evening (versus themiddle o the day) will help to minimizeammonia volatilization and improve

nitrogen availability. Applying manure at agronomic rates is one easy, eective, and important way to make sure you are not over applyingmanure nitrogen and increasing ammonialoss potential. Have the nutrient contento your manure tested regularly to ensurethat application rates match crop nutrientrequirements. In addition, knowledge o crop requirements and manure nutrientlevels can help avoid over-application.Higher application rates generally resultin greater emissions, so applying what is

needed based on soil type, yield goals, andnitrogen availability, but no more, will alsohelp maximize efciency and minimizeemissions.

References

Bittman, S. L. J. P. van Vliet, C. G.Kowalenko, S. McGinn, D. E. Hunt,and F. Bounaix. 2005. Surace-bandingliquid manure over aeration slots: a newlow-disturbance method or reducingammonia emissions and improving

yield o perennial grasses. Agronomy Journal 97:1304-1313.

Chen, Y., D.S. Petkau, and Q. Zhang. 2001.Evaluation o dierent techniques orliquid manure application on grassland.Applied Engineering in Agriculture17:489-496.

Kirchmann, H., and A. Lundvall. 1998.reatment o solid animal manures:identication o low NH3 emissionpractices. Nutrient Cycling inAgroecosystems 51:65-71.

Moal J. F., J. Martinez, F. Guiziou, and C.M. Coste. 1995. Ammonia volatilizationollowing surace-applied pig and cattleslurry in France. Journal o AgriculturalScience 125:245-252.

Puke, P. D., W. E. Jokela, and S. C.Boswoth. 2011. Ammonia volatilizationrom surace-banded broadcastapplication o liquid dairy manure ongrass orage. Journal o EnvironmentalQuality 40:374-382.

Further Reading

From the eXtension.org website:

 A Review of Manure Injection to

Control Odor and Ammonia Emissions

During the Land Application of Manure

Slurries

From the Colorado State University

Extension website:

1.631 Best Management Practices for 

Reducing Ammonia Emissions

7/30/2019 Best Managemetn Practices for Reducing Ammonia Emissions: Manure Application

http://slidepdf.com/reader/full/best-managemetn-practices-for-reducing-ammonia-emissions-manure-application 3/3

Colorado State University, U.S. Department of Agriculture and Colorado counties cooperating. CSU Extension

programs are available to all without discrimination. No endorsement of products mentioned is intended nor is

criticism implied of products not mentioned.

Sommer, S. G. and J. E. Olesen. 2000.Modelling ammonia volatilization romanimal slurry applied with trail hosesto cereals. Atmospheric Environment34:2361-2372.

Sommer, S.G., and N.J. Hutchings. 2001.Ammonia emission rom eld appliedmanure and its reduction. EuropeanJournal o Agronomy 15:1-15.

Waskom, R.M., and J.G. Davis. 1999. Bestmanagement practices or manureutilization. Colorado State University Cooperative Bulletin no. 568A.

Webb, J., S. Ellis, and D. Chadwick. 2004.Emission o ammonia and nitrousoxide ollowing incorporation intothe soil o armyard manures stored atdierent densities. Nutrient Cycling inAgroecosystems 70:67-76.