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Fact Sheet No. 1.631A Livestock Ser ies|Management

Colorado State University

Extension. 12/12.

www.ext.colostate.edu

by S.G. Lupis, K.J. Galles, J.M. Ham, J.J. Stratton, J.G. Davis, and N. Embertson*

Conned cattle eeding operations havebeen identied as a potential source oairborne ammonia emissions. Te majorityo ammonia produced at eedlots comes romresh urine on pen suraces. Even on pastures,urine spots are responsible or about 96% ototal ammonia emissions. Further, 80% o thetotal ammonia emissions rom urine spotsoccur during the rst 48 hours o exposure

to the atmosphere. Ammonia that is lost tothe atmosphere is no longer available ormanaged application as a nitrogen ertilizer,decreasing the nutritive value o eedlotmanure or land application.

Nitrogen transport rom east to west inColorado is seasonal and predictable. Duringspringtime, upslope conditions occasionallyoccur when easterly winds move rom theFront Range to the alpine areas o the RockyMountains, including Rocky MountainNational Park. Tereore, during springtime(when there is a higher risk o transporting

nitrogen to these high alpine areas) requentinterventions are suggested to controlemissions rom the pen surace.

Tere are various pen managementpractices that have the potential to reduceammonia emissions, especially whenimplemented to reduce emissions duringthe springtime weather patterns describedabove. For producers in Colorado and theFront Range, watering may be the mostcost-eective practice to reduce ammoniaemissions rom the eedlot pen.

Quick Facts

The majority of ammonia

produced at feedlots comes

from fresh urine on the pen

surface.

Most ammonia is emitted

from urine spots during the

rst48hoursofexposuretothe atmosphere.

Frequent but small water

applications reduce and

delay ammonia emissions

for several days and could

prevent transport of emissions

during critical times.

Typical dust control watering

systems can be employed for

ammonia emissions control

watering.

Other pen management

practices are less economical,

efcient,andpracticalfor

Colorado feedlot operators

compared to watering.

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

coordinator; K.J. Galles, Colorado State University,

graduate student, soil and crop sciences; J.M. Ham,

professor, soil and crop sciences; J.J. Stratton, graduate

student, chemistry; J.G. Davis, professor, soil and crop

sciences; N. Embertson, Whatcom Conservation District

in Lyndon, Washington, nutritient management and air

quality specialist. 12/12

Best Management Practices forReducing Ammonia Emissions:Feedlot Pen Management

Watering

Watering is a recognized bestmanagement practice (BMP) or controllingdust. Watering can be very expensive ithe inrastructure is not already in place;however, many producers already wateror dust control to reduce property linecomplaints. Watering may also be an eectiveway to control ammonia emissions.

Frequent (every 12-24 hours), small (0.2-inch) water applications have been shownto reduce and delay ammonia emissions orseveral days and could prevent transporto emissions, especially during springtimeupslope weather conditions that are mostlikely to deposit nitrogen in sensitive alpineareas. In a recent Colorado State Universitystudy o simulated watering events, 0.2 incho water was shown to reduce ammoniaemissions by 27% in the rst 24 hours andto slightly reduce the overall emissions (byabout 9%) over a 7-day period (Figure 1).Other studies have had similar results. Forexample, an 81% reduction in emissions wasreported when urine patches were exposed to~0.4 inch o rainall two hours aer urinationoccurred. In another example, ~0.1 inch orainall two hours aer urination reducedammonia emissions by 15%.

Tere are several reasons why wateringor precipitation events reduce ammoniaemissions. One reason is that the water maysimply move the ammonia away rom thepens surace, preventing exposure to the

atmosphere. Another explanation is that thewater dilutes the ammonia and minimizesammonia loss. Most likely, both explanationsare at work, and soil properties specic to aparticular site may also play a role.

Feedlot pen watering requires watersprinklers, either solid set on ences or aspart o a mobile truck unit. Either approachcan be eective or delivering requent, small

7/30/2019 Best Management Practices for Reducing Ammonia Emissions: Feedlot Pen Management

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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.

quantities or water to the pen surace. Tesetypes o watering systems are also widelyrecommended or controlling dust at largeeedlots. Many operators already employa watering system or dust control, so thatlittle, i any, inrastructure cost would beassociated with adopting this practice orammonia control.

Alternative PenManagement Practices

Other practices, such as requentmanure removal (i.e., scraping),application o aluminum sulate, and useo bedding (e.g., wood chips, compost, orsand) may be less economical and efcientor eedlot pen management compared towatering.

Pen scraping has the potential totemporarily increase ammonia emissionsbecause it disrupts the emissions-trappingcrust that can orm on the pen surace.However, timing scraping to avoid dayswhere upslope conditions are prevalent

can help to avoid deposition events andimprove the eectiveness o this practice.

Application o aluminum sulate atrecommended levels o 9,000 kg/ha wouldcost $1.3 million or a 30,000 head eedlotand is, thereore, not aordable or mostoperators. Sand, straw, and wood chipbedding is not typically used in eedlots,and so its use would require regularinvestments. Compost bedding, whenproduced on-site, is more cost-eectivethan other bedding materials, but requiresat least weekly maintenance to achieveoptimal reductions in ammonia emissions.

References

Baron, J. S., H. M. Rueth, A. M Wole, K. R.Nydick, E. J. Allstott, J. . Minear, andB. Boraska. 2000. Ecosystem responsesto nitrogen deposition in the ColoradoFront Range. Ecosystems 3:352-368.

Mukhtar, S. and B.W. Auvermann. 2009.Improving the air quality o animaleeding operations with properacility and manure management.exas Agricultural Extension Service

publication No. E-585.

Ndegwa, P. M., A. N. Hristov, J. Arogo,and R. E. Shefeld. 2008. A reviewo ammonia emission mitigationtechniques or concentrated animaleeding operations. BiosystemsEngineering 100:453-469.

Saarijrvi, K., P. K., Mattila, and P.Virkajrvi. 2006. Ammonia

volatilization rom articial dungand urine patches measured bythe equilibrium concentration

technique JI method). AtmosphericEnvironment 40:5137-5145.

Sweeten, J. M. 1990. Cattle eedlot wastemanagement practices or water and airpollution control. exas AgriculturalExtension Service publication No.B-1671.

Whitehead, D. C. and N. Raistrick. 1991.Eects o some environmental actorson ammonia volatilization romsimulated livestock urine applied to soil.Biology and Fertility o Soils 11:279-284.

Further Reading

Colorado State University Extension

fact sheet: 1.631 Best Management

Practices for Reducing Ammonia

Emissions

Figure 1. In a recent Colorado State University study, sprinkling 0.2 inch of water to intact feedlotsurface cores taken from fresh urine patches reduced ammonia emissions by 27% in the rst 24hours (Day 1) and by 9% over the entire 7-day test (Cumulative).

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