Ammonia Emissions from Manure Storages using Urine-feces Separation Systems

摘要

About 80% of dairy cattle N intake is excreted as urine and feces. Urinary-N is about 75% urea and fecal-N is mostly organic. Ammonia can only be volatilized when urinary urea is hydrolyzed by the urease enzyme present in the feces (urease is not present in the urine). Minimizing contact between urine and feces may be an effective approach to reducing urea hydrolysis and thus subsequent ammonia emissions; indeed, previous studies have reported 5 to 99% ammonia emissions mitigation within barns through separation of feces and urine. The objective of this study was to compare the efficacy of ammonia mitigation by separation of urine and feces in the waste stream against a conventional scrape manure handling method where urine and feces are comingled.Laboratory scale simulation studies were conducted to evaluate ammonia emissions from post-collection storages of three waste streams: i) idealistically separated feces and urine (no contact between urine and feces), ii) realistically separated urine andfeces, and Hi) conventionally scraped manure. From the results of this study, ammonia losses ranking in descending order was: aggregate of idealistically separated waste streams, aggregate of realistically separated urine and feces, and the scrape manure, respectively. Based on the results of our studies, therefore, the extra effort of separating the waste streams would not enhance mitigation of ammonia loss from the post-collection storages of the separated waste streams compared to the conventional scrape manure collection system.