Reduction of ammonia emissions from animal feeding operations is important from the perspective of environmental policy and its impact on agriculture. A laboratory study was conducted to evaluate how rate and frequency of urease inhibitor application affect ammonia emissions from simulated beef cattle feedyard manure surfaces. The urease inhibitor N-(n-butyl)thiophosphoric triamide (NBPT) was applied at rates of 0, 1, and 2 kg ha-1, at 8, 16, and 32 day frequencies, and with or without simulated rainfall. Synthetic urine was added every two days to the manure surface. Gaseous ammonia was trapped by bubbling through 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 NBPT ha-1 treatments resulting in 49% to 69% reduction in ammonia emission rates, respectively. The 8-day, 1 kg NBPT ha-1 treatments had the most promising benefit/cost ratios of 0.48 to 0.60. Simulated rainfall reduced the ammonia emission rates from 1% to 25% as compared to the non-rainfall treatments, although the differences were not statistically different. The use of NBPT for reducing ammonia emissions looks promising; however, possible buildup of urea in the pen surface may require a higher NBPT application rate with time.
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机译:从环境政策及其对农业的影响的角度来看,减少动物饲养活动中的氨排放非常重要。进行了一项实验室研究,以评估施用脲酶抑制剂的速率和频率如何影响模拟肉牛饲养场粪便表面的氨气排放。尿素酶抑制剂N-(正丁基)硫代磷酸三酰胺(NBPT)的施用频率分别为0、1、2 kg ha-1、8、16和32天,有或没有模拟降雨。每两天向粪便表面添加合成尿。通过使用真空系统鼓泡通入硫酸溶液来捕集气态氨,并使用自动化程序分析氮。每8天施用NBPT最有效,分别进行1千克和2千克NBPT ha-1处理后,氨排放率分别降低49%至69%。 8天,1千克NBPT ha-1处理的收益/成本比为0.48至0.60,是最有希望的。与非降雨处理相比,模拟降雨将氨的排放率从1%降低到25%,尽管差异没有统计学差异。使用NBPT减少氨气排放看起来很有希望;但是,随着时间的流逝,尿素可能在笔表面积聚,可能需要更高的NBPT施用率。
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