Multiple-chamber steady-state gas emission detection from dairy manure slurry

Eileen F. Wheeler, Patrick A. Topper, Neil E. Brown, Gabriella A. Varga

Research output: Contribution to conferencePaperpeer-review

19 Scopus citations


In order to evaluate gas emission reduction potential of nutritional changes in lactating dairy cattle diets, an instrumentation system was developed to rapidly and accurately evaluate multiple treatments at one time. Six steady-state flux chambers were coupled via a multiplexer relay board and software with a photoacoustic multi-gas monitor to measure the concentration of ammonia and three greenhouse gases released from manure samples every 20 minutes over 24 hours. Each chamber sweep air flow rate was maintained at 0.5 air changes per minute via a calibrated flow meter. Five chambers evaluated emissions from manure samples consisting of 100 grams each of urine and feces from each cow on trial. This 50:50 urine:feces ratio produced as much or more ammonia gas than other ratios over 1 to 24 hour periods. The sixth chamber was filled with 200 grams of demineralized water for the initial gas concentration used in calculations. Emission was represented as the integral of gas released from the manure over a chosen time period. Results from five sub-samples of collected freestall manure had a standard error of 2% of the mean emission. Instrumentation use on manure slurry from trial cows was able to differentiate between diets but explanation of results may require additional information about other factors influencing gas emission. Results suggest that this method offers repeatable, simultaneous monitoring of gas emission from manure and offers potential to evaluate factors affecting emissions thus allowing better understanding and management of on-farm gas sources.

Original languageEnglish (US)
StatePublished - 2007
EventInternational Symposium on Air Quality and Waste Management for Agriculture - Broomfield, CO, United States
Duration: Sep 16 2007Sep 19 2007


OtherInternational Symposium on Air Quality and Waste Management for Agriculture
Country/TerritoryUnited States
CityBroomfield, CO

All Science Journal Classification (ASJC) codes

  • Agronomy and Crop Science
  • Pollution
  • Waste Management and Disposal

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