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Our Study

Colorado State University is currently conducting a NRCS-CIG grant sponsored study entitled On-farm Evaluation and Demonstration of Ammonia Reduction Best Management Practices (BMPs) for Feedlots and Dairies. The study is ongoing from Spring 2007 to Spring 2009.

There are four parts of the study:

Literature Review

The first part of the project was to conduct a comprehensive literature review to identify BMPs that had been shown in research studies to have potential for ammonia reduction on dairy and feedlot operations. Based on our review, we identified the following BMPs as practices that have been shown to reduce ammonia on feedlots and dairies. The BMPs with check in "Test On-Farm" column are ones that we are planning to test on dairy and feedlot operations since they have the most promise at reducing ammonia emissions.

Ammonia BMPs
Dairy
Feedlot
Test
On-Farm
Drylot
Freestall
Nutrition
  Decrease dietary CP and Phase Feeding (click on dairy or feedlot "x" to left)
-
Conventional vs. naturally fed cattle (additives vs. no additives in the feed)
-
-
x
x
  Use oscillating protein
x
x
x
-
  Increase efficiency (high vs. low producers)
x
x
-
x
Correlate feeding time with natural crepuscular (dawn and dusk) feeding behavior
-
-
x
-
Housing
  Freestall (Dairy)
  Increase manure removal rate
-
x
-
x
  Manure removal technique
-
x
-
x
  Floor surface modification
-
x
-
-
  Freestall bedding type
-
x
-
x
  Treat flush water
-
x
-
-
  Fresh vs. recycled flush water
-
x
-
-
  Drylot (Dairy and Feedlot)
  Increase manure removal rate
-
-
x
x
  Drylot bedding (bed vs no bed & type)
x
-
x
x
  Harrow bedding into pen
x
-
-
x
  Provide shade
x
-
x
x
  Decrease soil pH (i.e. alum application)
x
-
x
x
  Change pen moisture level
x
-
x
x
Manure Management
  Increase solid separation efficiency
x
x
-
-
  Stockpile vs. mounding in pens
-
-
x
x
  In-pen vs. out-of-pen stockpiling
-
-
x
x
  Acidification of lagoon
x
x
-
-
  Aeration of lagoon
x
x
-
x
  Multiple lagoons vs. single
x
x
-
-
  Stockpiling vs. composting of manure
x
x
x
x
  Cover lagoon (i.e. natural crust, cover, etc.)
x
x
-
x
  Cover compost
x
x
x
-
  Compost C:N ratio (click on dairy or feedlot "x" to left)
x
Land Application
  Solid vs. liquid manure application
x
x
x
-
  Injection of slurry
-
x
x
-
  Incorporate manure immediately
x
x
x
-

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Survey

A detailed survey was sent to dairy and feedlot producers in Colorado, Iowa, Nebraska, and Kansas to learn about producer’s current BMP practices. The survey responses have been very beneficial in showing us what types of BMPs producers are already implementing and what are their constraints to further adoption of additional BMPs. We have also gained knowledge on producer’s current management practices, their opinion of the profitability of BMPs, how easy they think BMPs are to use, the perceived cost of implementation, and what they think are the water and air quality impacts of BMPs.

What we have learned so far is that producers are driven by a combination of factors including cost and ease of implementation and effectiveness, rather than solely by a BMPs ability to reduce negative air quality impacts.

For more detailed survey results click here!

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Field Testing

The third part of the project is to test the BMPs selected from the literature review on actual dairy and feedlot operations in order to evaluate the ammonia reduction potential, ease of use, and cost of the technologies. Field testing is vital to the validity of the BMPs, as most have only been tested under laboratory conditions, which is not a true indicator of real world conditions.

To date, we have conducted one season of field trials and have a full season ahead with field measurements from May to September 2008.

Set-up

Different BMPs require different measurement techniques. For surface measurements, we used a unique surface emission collector developed at Colorado State University. The system can be used to measure ammonia concentrations from pen surfaces, compost piles, lagoon surfaces, alleyways, and more. The device works by collecting surface emissions through Teflon tubing, which is protected by a PVC cap staked 4 inches above the ground surface (Figure 1). The cap is used to prevent moisture, dust, and dry deposition of gas from entering the sampling lines. The system is unique because it does not disturb the normal surface flux behavior, and thus does not alter the rate and concentration of surface emissions like other measurement devices can (i.e. flux chambers, wind tunnels, etc.).

Sampler Composite Sampler Nitrolux S

Sampling lines (8 or 16 depending on the application) collect ambient air under vacuum into a composite sampling device (Figure 2). The PVC sampling device pulls air from the sampling lines at equal rates and mixes it in a closed container. From this mixed sample, a real-time ammonia analyzer (Nitrolux-S, Pranalytic, CA) actively collects the mixed sample air (Figure 3). The real-time analyzer uses laser photoacoustic spectroscopy for the optical absorption of ammonia in the analyzed sample. The analyzer was developed for livestock applications and is the most accurate ammonia analyzer in its class. Samples are logged every 1 to 2 minutes for accurate analysis of surface ammonia concentration trends and variations over time.

In addition to surface measurements, this system can also be used to sample ambient air. To do this, tubing can be attached at various heights to stakes, railing, or inside structures. This is useful when monitoring the concentration of ammonia inside buildings, at fence-line, or in enclosed manure storage systems.

Meteorological data is also collected with a real-time mobile weather station located at the sampling site.

Results

*It is important to note that not all BMPs are viable on every operation. BMPs must be selected individually for an operation based on current management practices, BMPs already in place, operation layout, economics, and ammonia reduction goals. Additionally, the BMP with the most proven potential for ammonia reduction might not exhibit the same results on every operation. BMPs should be chosen wisely and monitored for effectiveness on a continuous basis. This website is a resource to help a producer to choose the BMPs appropriate for their dairy or feedlot.*

Results include the effectiveness of the BMP at reducing ammonia, how easy the BMP is to install and/or use, and the cost of implementing the technology. All of these parameters are addressed in the results of each BMP.

For results on individual BMPs tested, please click on the desired link below:

Dairy

Feedlot

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Education and Outreach

The final part of the project is the development of a comprehensive ammonia reduction strategy plan based on the most effective, field tested BMPs. The plan will be composed of an online factsheet series, a BMP photo gallery, and ammonia reduction and implementation cost-estimator. These materials should be available by March 2009.

Producers, industry representatives, and regulators will be informed through this webpage and the online tools mentioned above. For more information on education materials or to set up an educational seminar on ammonia BMPs, please contact us.

*It is important to note that not all BMPs are viable on every operation. BMPs must be selected individually for an operation based on current management practices, BMPs already in place, operation layout, economics, and ammonia reduction goals. Additionally, the BMP with the most proven potential for ammonia reduction might not exhibit the same results on every operation. BMPs should be chosen wisely and monitored for effectiveness on a continuous basis. This website is a resource to help a producer to choose the BMPs appropriate for their dairy or feedlot.*

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