文章基本信息

标题：Ammonium sorption and ammonia inhibition of nitrite-oxidizing bacteria explain contrasting soil N2O production
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作者：Rodney T. Venterea ; Timothy J. Clough ; Jeffrey A. Coulter 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2015
卷号：5
期号：1
DOI：10.1038/srep12153
语种：English
出版社：Springer Nature
摘要：Better understanding of process controls over nitrous oxide (N₂O) production in urine-impacted ‘hot spots’ and fertilizer bands is needed to improve mitigation strategies and emission models. Following amendment with bovine ( Bos taurus ) urine (Bu) or urea (Ur), we measured inorganic N, pH, N₂O, and genes associated with nitrification in two soils (‘ L ’ and ‘ W ’) having similar texture, pH, C, and C/N ratio. Solution-phase ammonia ( sl NH₃) was also calculated accounting for non-linear ammonium (NH₄⁺) sorption capacities (ASC). Soil W displayed greater nitrification rates and nitrate (NO₃⁻) levels than soil L , but was more resistant to nitrite (NO₂⁻) accumulation and produced two to ten times less N₂O than soil L . Genes associated with NO₂⁻ oxidation ( nxr A) increased substantially in soil W but remained static in soil L . Soil NO₂⁻ was strongly correlated with N₂O production, and cumulative ( c- ) sl NH₃ explained 87% of the variance in c- NO₂⁻. Differences between soils were explained by greater sl NH₃ in soil L which inhibited NO₂⁻ oxidization leading to greater NO₂⁻ levels and N₂O production. This is the first study to correlate the dynamics of soil sl NH₃, NO₂⁻, N₂O and nitrifier genes, and the first to show how ASC can regulate NO₂⁻ levels and N₂O production.