Denitrification potential under different fertilization regimes is closely coupled with changes in the denitrifying community in a black soil

Abstract

Preferable inorganic fertilization over the last decades has led to fertility degradation of black soil in Northeast China. However, how fertilization regimes impact denitrification and its related bacterial community in this soil type is still unclear. Here, taking advantage of a suit of molecular ecological tools in combination of assaying the potential denitrification (DP), we explored the variation of activity, community structure, and abundance of nirS and nirK denitrifiers under four different fertilization regimes, namely no fertilization control (N0M0), organic pig manure (N0M1), inorganic fertilization (N1M0), and combination of inorganic fertilizer and pig manure (N1M1). The results indicated that organic fertilization increased DP, but inorganic fertilization had no impacts. The increase of DP was mirrored by the shift of nirS denitrifiers' community structure but not by that of nirK denitrifiers'. Furthermore, the change of DP coincided with the variation of abundances of both denitrifiers. Shifts of community structure and abundance of nirS and nirK denitrifiers were correlated with the change of soil pH, total nitrogen (TN), organic matter (OM), C:P, total phosphorus (TP), and available phosphorus (Olsen P). Our results suggest that the change of DP under these four fertilization regimes was closely related to the shift of denitrifying bacteria communities resulting from the variation of properties in the black soil tested.

Dynamics of ammonia oxidizers and denitrifiers in response to compost addition in black soil, Northeast China

“…The abundance of denitrifier genes including nirS, nirK and nosZ were greatly enhanced by compost addition, which is consistent with previous studies (Kleineidam et al, 2010;Yin et al, 2015;Cui et al, 2016;Pereg et al, 2018;Tao et al, 2018). Random forest analysis indicated that SOM content contributed greatly to nirS, nirK and nosZ gene abundance.…”

“…However, others observed that organic fertilizers showed no significant effect on AOA, while AOB abundance and composition was sensitive in calcareous desert soils (Tao et al, 2017). In addition, documented publications indicated that the effect of organic application on denitrifiers can be positive (Yin et al, 2015;Cui et al, 2016;Pereg et al, 2018) or neutral (Miller et al, 2008;Sun et al, 2015) in agricultural soils. Such varying observations indicated that there is still need to examine the effect of organic fertilization on ammonia oxidizers and denitrifiers.…”

Unravelling the effects of tropical land use conversion on the soil microbiome

“…It was previously reported that nirK and nirS are positively correlated with increasing soil pH [53], which is in line with measurements conducted in our sampling sites [18] and multivariate analysis showing a significant influence of pH on microbial communities. Previous studies also described distinct distributions of the two different denitrification genes nirK and nirS among taxa, with nirK being associated to Rhizobiales [54]. Accordingly, most detected nirK sequences in our dataset originated from Rhizobiales.…”

Influence of 34-years of fertilization on bacterial communities in an intensively cultivated black soil in northeast China

“…High-throughput sequencing technologies can provide significant insights into species and functional diversity of microbial populations with different fertilizer regimes (Hallin et al, 2009;Ye et al, 2013;Zhao et al, 2014). Recent results suggest that the change of potential denitrification under long-term fertilization regimes was closely related to the shift in denitrifying bacteria communities resulting from the variation of properties in black soil (Yin et al, 2015). In the long term, such modifications may result in shifts in the quality and functionality of the soils (Beauregard et al, 2010).…”