Community Structure of Ammonia-Oxidizing Bacteria under Long-Term Application of Mineral Fertilizer and Organic Manure in a Sandy Loam Soil

Abstract

The effects of mineral fertilizer (NPK) and organic manure on the community structure of soil ammoniaoxidizing bacteria (AOB) was investigated in a long-term (16-year) fertilizer experiment. The experiment included seven treatments: organic manure, half organic manure N plus half fertilizer N, fertilizer NPK, fertilizer NP, fertilizer NK, fertilizer PK, and the control (without fertilization). N fertilization greatly increased soil nitrification potential, and mineral N fertilizer had a greater impact than organic manure, while N deficiency treatment (PK) had no significant effect. AOB community structure was analyzed by PCRdenaturing gradient gel electrophoresis (PCR-DGGE) of the amoA gene, which encodes the ␣ subunit of ammonia monooxygenase. DGGE profiles showed that the AOB community was more diverse in N-fertilized treatments than in the PK-fertilized treatment or the control, while one dominant band observed in the control could not be detected in any of the fertilized treatments. Phylogenetic analysis showed that the DGGE bands derived from N-fertilized treatments belonged to Nitrosospira cluster 3, indicating that N fertilization resulted in the dominance of Nitrosospira cluster 3 in soil. These results demonstrate that long-term application of N fertilizers could result in increased soil nitrification potential and the AOB community shifts in soil. Our results also showed the different effects of mineral fertilizer N versus organic manure N; the effects of P and K on the soil AOB community; and the importance of balanced fertilization with N, P, and K in promoting nitrification functions in arable soils.

Effects of dicyandiamide and acetylene on N2O emissions and ammonia oxidizers in a fluvo-aquic soil applied with urea

“…6), confirming similar results obtained from various agricultural soils (Phillips et al 2000;Chu et al 2007;Ouyang et al 2016). It has been suggested that Nitrosospira cluster 3 often outcompeted other Nitrosospira under fertile soil conditions (Tourna et al 2010).…”

Nitrogen and phosphorus enrichment alter the composition of ammonia-oxidizing bacteria in salt marsh sediments

“…Alternatively, perhaps in this ratio the plants were able to take up most of the nutrients before the AOB community could respond. In contrast, Chu et al (2007) observed similar DGGE bands and amoA copy numbers in NPK, NP and NK treatments in agricultural soils. Experiments that apply different ratios of N and P would be necessary to tease apart the interactive effects of these nutrients.…”

“…In a different New England salt marsh, Horner-Devine et al, (2004) observed a correlation between AOB composition and phosphate concentrations; pairwise samples with more similar phosphate concentrations contained more similar communities. In agricultural soils, Chu et al (2007) found differences in DGGE banding patterns of the amoA gene between control and PK (phosphorus and potassium)-enriched plots, but did not find differences in amoA copy numbers (Chu et al, 2008) or soil nitrification potentials.…”

The Biogeography of Ammonia-Oxidizing Bacterial Communities in Soil

“…However, while Nitrosopira cluster 2 was relatively abundant in three forest soil libraries (BF1, BZ2, BZ3) with reasonably low pHs (4.05-5.36), there was no overall correlation between the relative abundances of cluster 2 in the libraries and soil pH (ρ=0.15, P=0.3) suggesting that cluster 2 AOB do not necessarily have higher relative abundances in acidic soils. Likewise, results from previous studies [14][15][16]20] have contributed to the hypothesis that representatives of Nitrosospira cluster 3 are likely to be relatively more abundant in soils with higher levels of N availability. If we examine the proportional abundances of Nitrosospira cluster 3, we see no correlations with our measured indices of N availability (N mineralization rates and extractable NH 4 + or the sum of NH 4 + plus NO 3 − concentrations, P>0.4 in all cases).…”

“…We do know that distinct soils often harbor distinct AOB communities. A number of environmental factors, including vegetation type [9][10][11], soil nutrient levels [12][13][14][15][16], soil microclimate [13,17,18], and management practices [19][20][21], have been found to have an important influence on the spatial variability exhibited by AOB communities. However, because most studies have compared AOB communities across a rather limited number of samples, with one notable exception being the study by Avrahami and Conrad [18], it has been difficult to ascertain which soil biotic and abiotic characteristics are related to AOB community composition across larger spatial scales.…”