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Iowa State University

2004

Air quality

Articles 1 - 2 of 2

Full-Text Articles in Engineering

Application Rate And Timing Effects On Urease Inhibitor Performance For Minimizing Ammonia Emissions From Beef Cattle Feedyards, David B. Parker, Syam Pandrangi, L. Wayne Greene, Lal K. Almas, N. Andy Cole, Marty B. Rhoades, Jacek A. Koziel Aug 2004

Application Rate And Timing Effects On Urease Inhibitor Performance For Minimizing Ammonia Emissions From Beef Cattle Feedyards, David B. Parker, Syam Pandrangi, L. Wayne Greene, Lal K. Almas, N. Andy Cole, Marty B. Rhoades, Jacek A. Koziel

Jacek A. Koziel

A laboratory study was conducted to evaluate how rate and timing of urease inhibitor application affects ammonia emissions from simulated beef cattle feedyard surfaces. The urease inhibitor N-(n-butyl)thiophosphoric triamide (NBPT) was applied at rates of 0, 1 and 2 kg/ha, at 8, 16, and 32 day frequencies, and with or without simulated rainfall. Synthetic urine was added every 2 days to the manure surface. Gaseous NH3 was trapped in a sulfuric acid solution using a vacuum system and analyzed for nitrogen using automated procedures. NBPT applied every 8 days was most effective, with the 1 and 2 kg/ha NBPT treatments …


Ambient Ammonia And Hydrogen Sulfide Concentrations At A Beef Cattle Feedlot In Texas, Jacek A. Koziel, Bok-Haeng Baek, Jarett P. Spinhirne, David B. Park Aug 2004

Ambient Ammonia And Hydrogen Sulfide Concentrations At A Beef Cattle Feedlot In Texas, Jacek A. Koziel, Bok-Haeng Baek, Jarett P. Spinhirne, David B. Park

Jacek A. Koziel

Concentrations of ammonia (NH3) and hydrogen sulfide (H2S) in ambient air were semicontinuously measured at a 50,000-head cattle feedyard in Texas panhandle in three seasons: fall 2002 (10 days), winter 2003 (14 days), and spring 2003 (15 days). Sampling was conducted at 1.5 m above the ground at one location each season at the western fence line of cattle pens. Gas concentrations were measured using continuous analyzers housed in an onsite instrument shelter. Measured concentrations were upwind or downwind of the feedyard pens depending on the wind direction. Wind directions, wind velocity, and air temperature were measured to correlate them …