Institute of Bio- and Geosciences - Agrosphere (IBG-3), Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.
Sci Rep. 2017 Feb 1;7:39590. doi: 10.1038/srep39590.
Abiotic conversion of the reactive nitrification intermediate hydroxylamine (NHOH) to nitrous oxide (NO) is a possible mechanism of NO formation during nitrification. Previous research has demonstrated that manganese dioxide (MnO) and organic matter (OM) content of soil as well as soil pH are important control variables of NO formation in the soil. But until now, their combined effect on abiotic NO formation from NHOH has not been quantified. Here, we present results from a full-factorial experiment with artificial soil mixtures at five different levels of pH, MnO and OM, respectively, and quantified the interactive effects of the three variables on the NHOH-to-NO conversion ratio (R). Furthermore, the effect of OM quality on R was determined by the addition of four different organic materials with different C/N ratios to the artificial soil mixtures. The experiments revealed a strong interactive effect of soil pH, MnO and OM on R. In general, increasing MnO and decreasing pH increased R, while increasing OM content was associated with a decrease in R. Organic matter quality also affected R. However, this effect was not a function of C/N ratio, but was rather related to differences in the dominating functional groups between the different organic materials.
非生物转化活性亚硝酸盐（NHOH）为一氧化二氮（NO）是硝化过程中形成 NO 的一种可能机制。先前的研究表明，土壤中的二氧化锰（MnO）和有机物（OM）含量以及土壤 pH 值是控制土壤中 NO 形成的重要变量。但到目前为止，它们对 NHOH 非生物形成 NO 的综合影响尚未量化。在这里，我们在人工土壤混合物中进行了一个完全因子实验，分别在五个不同的 pH 值、MnO 和 OM 水平下进行，并量化了三个变量对 NHOH-NO 转化率（R）的交互作用。此外，通过向人工土壤混合物中添加四种具有不同 C/N 比的不同有机材料，确定了 OM 质量对 R 的影响。实验表明，土壤 pH 值、MnO 和 OM 对 R 有很强的交互作用。一般来说，增加 MnO 和降低 pH 值会增加 R，而增加 OM 含量则会降低 R。有机物质量也会影响 R。然而，这种影响不是 C/N 比的函数，而是与不同有机材料之间占主导地位的功能基团的差异有关。
