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

Abstract

Ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) are crucial for N 2 O emission as they carry out the key step of nitrification. Dicyandiamide (DCD) and acetylene (C 2 H 2 ) are typical nitrification inhibitors (NIs), while the comparative effects of these NIs on N 2 O production and ammonia oxidizers' (AOB and AOA) growth are unclear. Four treatments including a control, urea, urea + DCD, and urea + C 2 H 2 were set up to investigate their effect of inhibiting soil nitrification, nitrification-related N 2 O emission as well as the growth of ammonia oxidizers with a fluvo-aquic soil using microcosms for 28 days. N 2 O emission and net nitrification rate increased after the application of urea, but were significantly restrained in urea + NI treatments, while C 2 H 2 was more effective in reducing N 2 O emission and nitrification rate than DCD. The abundance of AOB, which was significantly correlated with N 2 O emission and net nitrification rate, was more inhibited by C 2 H 2 than DCD. Furthermore, the application of urea in all the soils had little impact on the AOA community, while obvious shifts of AOB community structure were found compared with the control. All AOB sequences fell within Nitrosospira cluster 3, and the AOA community was clustered to group 1.1b. Collectively, it indicated that application of urea combined with NIs (DCD or C 2 H 2 ) could potentially alter N 2 O emission, mainly through regulating the growth of AOB but not AOA in this fluvo-aquic soil.

Responses of soil ammonia oxidation and ammonia-oxidizing communities to land-use conversion and fertilization in an acidic red soil of southern China

“…The AOA phylogenetic analysis suggested that the AOA gene sequences were aligned to group 1.1b and group 1.1a, whereas the T-RF 540 bp belonging to the group 1.1a showed the highest relative abundance. These results were in well agreement with former studies that group 1.1a could possibly be more abundant in acidic red soils, while group 1.1b was more adaptable to neutral and alkaline soils [21,46]. Former results also suggested that the group 1.1a-associated lineage could possibly be tolerant with limiting oxygen than soil group 1.1b [18].…”

“…The AOB phylogenetic analyses showed that Nitrosospira cluster like AOB exclusively predominate the community compositions of bacterial ammonia-oxidizers in acidic red soils, which were in line with results obtained from former agriculture soils [37,46]. It was proposed that AOB belonged to Nitrosomonas spp (cluster 7&8) were exclusively detected in the rice paddies, whereas AOB within Nitrosospira spp (cluster 2&0) was observed only in the upland soils [37,46]. However, no such distinct phenomenon was observed in our study, which might relate to the soil samplings used for the physiological analysis (day in the drainage period).…”

“…Our results demonstrated that the environmental factors induced by land-use conversion determined the phylogenetically AOA also depend on the fertilization management (Fig .3a). The AOB phylogenetic analyses showed that Nitrosospira cluster like AOB exclusively predominate the community compositions of bacterial ammonia-oxidizers in acidic red soils, which were in line with results obtained from former agriculture soils [37,46]. It was proposed that AOB belonged to Nitrosomonas spp (cluster 7&8) were exclusively detected in the rice paddies, whereas AOB within Nitrosospira spp (cluster 2&0) was observed only in the upland soils [37,46].…”

Ectomycorrhizal fungi inoculation alleviates simulated acid rain effects on soil ammonia oxidizers and denitrifiers in Masson pine forest

“…The 50 μl reaction mixture contained 25 μl Premix Ex Taq (TaKaRa, Dalian, China), 1 μl of each primer (10 μM) and 2 μl of diluted template DNA (1–10 ng). The labelled PCR products were purified using the Gel Extraction Kit (Qiagen, Hilden, Germany), and then, the purified PCR products were digested with restriction enzymes HpyCH4V for AOA amoA gene (Hu et al ., ), RsaI for AOB amoA gene (Wang et al ., ), HaeIII for nirK gene (Guo et al ., ), MspI for nirS gene (Guo et al ., ) and MspI for nosZ gene (Hu et al ., ) respectively. The size and relative abundance of T‐RFs were determined by a 3730xl DNA Analyser (Applied Biosystems, Carlsbad, USA).…”

Measurement and Correlation of Solubility of Dicyandiamide in Five Binary Solvents from 283.15 to 323.15 K

“…Bronson et al studied the decomposition rate and nitrification inhibition of DCD . As a nitrification inhibitor, DCD has an impact on N 2 O emissions. − DCD is an important industrial raw material, which has many applications, not only in the printing and dyeing industry but also in the electronics industry. − In addition, DCD is also used as an intermediate in fine chemicals. In medicine, DCD is used to produce guanidine nitrate and sulfa drugs.…”