Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/27/2014
Publication Date: 11/4/2014
Citation: Waldrip, H., Todd, R.W., Cole, N.A. 2014. Can surface-applied zeolite reduce ammonia losses from feedyard manure? A laboratory study. ASA-CSSA-SSSA Annual Meeting Abstracts. Paper No.260-6.
Technical Abstract: Ammonia emission from beef cattle feedyard manure results in losses of nitrogen (N), which may negatively affect environmental quality. The magnitude and rate of ammonia volatilization from feedyards partially depends on the amount of urinary urea excreted and ionization of ammonium into ammonia following urea hydrolysis. Zeolite clinoptilolite is a naturally occurring, porous aluminosilicate mineral that can sorb and sequester cations within its negatively charged framework structure. Zeolite has been used to mitigate ammonia losses and improve fertilizer value of compost and manure in livestock barns. Zeolite application to pen surfaces could be a practical and cost-effective means of reducing ammonia losses; however, few studies have evaluated its efficacy on open-lot beef cattle feedyards. Objectives of this study were to (1) characterize ammonium sorption by zeolites with differing physicochemical properties and (2) evaluate zeolite effects on rates and cumulative losses of ammonia following urine application to feedyard manure. Batch incubation studies with four commercially available zeolites revealed that ammonium sorption by zeolite was rapid (1 to 2 h) with large differences in sorption potential largely related to zeolite pH. Maximum sorption ranged from 28 to 97 cmol ammonia-N per kg zeolite. Effects of zeolite application rate [0.5% to 10.0% of manure dry matter (DM)] on sorption and desorption characteristics in a manure/urine matrix were highly variable but tended to be proportional to zeolite application rate: as little as 0.5% zeolite increased ammonium recovery up to 19%. In flow-through chamber studies, higher rates of zeolite did not reduce cumulative ammonia emissions, as 1.0% zeolite reduced cumulative ammonia emission by 42% and 5.0% zeolite reduced N losses by only 18% compared to unamended manure. Surface application of zeolite has potential for mitigating feedyard ammonia losses, but specific zeolite properties influenced its effectiveness.