Dissimilatory nitrate reduction to ammonia (DNRA) is one of the three processes of soil nitrate reduction. However, relationships between DNRA microbes and nutrient fertilization are poorly known. We studied the DNRA microbial community in a Ferralic Cambisol containing plots including control without fertilization, swine manure fertilization (M), chemical fertilization (NPK), and chemical/manure combined fertilization (MNPK) treatments. The abundance of DNRA microbes, represented by the nrfA gene abundance, ranged from 2 × 10⁷ to 5.8 × 10⁷ g⁻¹ dry soil and was positively correlated with soil moisture and total phosphorus (TP) and negatively correlated with NH₄⁺ and total potassium (TK). The potential DNRA rate ranged from 0.5 to 1.5 μg N g⁻¹ dry soil h⁻¹. The α-diversity of the DNRA bacteria increased in the M-treated plots, and the dominant DNRA bacterial OTUs were assigned to the phyla Proteobacteria, Verrucomicrobia and Acidobacteria. PCoA and redundancy analysis indicated that the composition of the DNRA bacteria was strongly impacted by the long-term fertilization regimes and was associated with pH, TN, TP and TC followed by moisture, NH₄⁺ and C/NO₃⁻. Interestingly, the composition of the DNRA bacterial community, the properties of the soil (TP, AK and C/N) and the interactions of these factors (soil properties × DNRA composition) explained the DNRA rate. Collectively, these data suggested that the DNRA potential in the Ferralic Cambisol is possibly controlled by the stoichiometry of macronutrient and the composition of DNRA microbes but not their total abundance.

硝酸盐异化还原为氨（DNRA）是土壤硝酸盐还原的三个过程之一。但是，DNRA微生物与养分施肥之间的关系知之甚少。我们研究了在一个含铁的坎地索尔土壤中的DNRA微生物群落，该区域包括不施肥的对照，猪粪施肥（M），化学施肥（NPK）和化学/肥料联合施肥（MNPK）处理。以nrfA基因丰度表示的DNRA微生物丰度范围为2×10 ⁷至5.8×10 ⁷  g ^-1干旱土壤，与土壤水分和总磷（TP）正相关，与NH ₄ ⁺负相关和总钾（TK）。潜在的DNRA速率为0.5至1.5μgN g ^-1干燥土壤h ^-1。所述DNRA细菌的α-多样性在M-处理的样增加，并且主导DNRA细菌个OTU被分配到门类变形菌，疣微菌门和酸杆菌门。后交通动脉和冗余分析表明，细菌DNRA的组成强烈地长期施肥方式影响，并与pH值相关联，TN，TP和TC随后湿气，NH ₄ ⁺和C / NO ₃ ^-。有趣的是，DNRA细菌群落的组成，土壤的性质（TP，AK和C / N）以及这些因素的相互作用（土壤性质×DNRA组成）解释了DNRA的发生率。总的来说，这些数据表明，在铁性坎比索中的DNRA潜力可能受大量营养物的化学计量和DNRA微生物组成的控制，但不受其总丰度的控制。