Seasonality of gross ammonification and nitrification altered by precipitation in a semi-arid grassland of Northern China

doi:10.1016/j.soilbio.2021.108146

Soil Biology and Biochemistry

Volume 154, March 2021, 108146

https://doi.org/10.1016/j.soilbio.2021.108146 Get rights and content

Highlights

•
Gross ammonification/nitrification (GA/GN) was strengthened by precipitation.
•
Temperature is limiting GA before and after the growing season.
•
GN is tightly coupled to substrate supply by GA.
•
Extreme drought with 60% precipitation reduction might terminate GA and GN.

Abstract

Gross ammonification (GA) and gross nitrification (GN) are key regulators of the bioavailability of nitrogen (N) in terrestrial ecosystems. In arid and semi-arid grassland ecosystems, the impacts of precipitation change on in situ GA and GN and their seasonal variations are understudied. A manipulative experiment with five precipitation levels (−60%, −30%, unchanged ambient precipitation as control, +30%, +60% of ambient precipitation) was set up in May 2012. After a 2-year equilibration period, the ¹⁵N pool dilution technique was applied to determine GA and GN rates in surface soil (0–5 cm) within 8 sampling dates ranging from the onset to the end of the growing season. Pronounced temporal variability of GA and GN rates were observed with the highest GA and GN rates in the mid-growing season (August) and the lowest in the post-growing season (October). GA rates during the growing season were primarily controlled by precipitation and soil water availability, while this effect diminished at the onset and end of the growing season when the temperature dropped. In contrast, GN was predominately controlled by ammonium (NH₄⁺) production through GA. In the peak-growing season, the +60% precipitation treatment enhanced GA and GN rates by up to 4-fold, while the −30% precipitation treatment marginally suppressed GA and GN rates. The −60% precipitation treatment suppressed GA and GN rates to below detection limits across the entire study period, suggesting that extreme and persistent droughts greatly inhibited N turnover in the surface soil, thereby forcing plants to mobilize and access nutrients from deeper soil layers. Our findings provide a season-specific mechanistic insight into precipitation impacts on topsoil gross N turnover and suggest that the N cycling represented in ecosystem models needs to consider a mechanism that allows a strong suppression of microbial functions under extreme droughts.

Section snippets

1Introduction

The Eurasian steppes are the second-largest continuous biome on Earth, covering up to 7% of the Earth's total land surface and play a major ecological role, e.g. contributing to the global carbon sink (Bai et al., 2008). Besides limited by nitrogen (N), the productivity of semi-arid grassland ecosystem is also strongly affected by changes in precipitation at various temporal scales (Bai et al., 2004; Bernacchi and VanLoocke, 2015). For example, precipitation affects the microbial production of

2.1Study site and experimental design

This study was conducted in the West Ujinmqin Banner, Inner Mongolia, China (44°22′N, 117°35′E, 1148 m a.s.l). The study area is a typical semi-arid grassland with Chestnut soil (Su et al., 2006) or Calcic Chernozem soil according to ISSS Working Group RB. The soil texture is loamy sand (sand: 78–80.%; silt:17–19%; clay:2–3%) (Bai et al., 2010). Soil organic carbon, total N concentrations and plant biomass are presented in Table 1 (Zhang, 2016). Soil field water capacity in this area is 25.3%

3.1Soil temperature (ST), soil water-filled pore space (WFPS) and soil dissolved N concentrations

A typical seasonality of precipitation, air temperature, ST and WFPS was found in the two study years in 2014 and 2015 (Fig. 1). The annual precipitation was remarkably different between the two experimental years, with 222 mm in 2014 and 312 mm in 2015. Most of rainfall occurred from April to September (Fig. 1). In contrast to precipitation, mean growing season air temperatures did not differ between the two years, 12.2 °C in 2014 and 11.9 °C in 2015. The highest mean monthly temperature

4.1Gross N turnover in semi-arid steppe soils

In this study, we found relatively low rates of GA (mean of 0.6 mg N kg⁻¹ sdw (soil dry weight) d⁻¹) and GN (mean of 0.8 mg N kg⁻¹ sdw d⁻¹). This is smaller than the rates observed for temperate alpine grasslands (ranging from 1.8 to 2.0 mg N kg⁻¹ sdw d⁻¹ reported in southern Germany) but comparable to those of other semi-arid grassland systems (Booth et al., 2005; Wu et al., 2012; Gerschlauer et al., 2016). The use of the ¹⁵N pool dilution technique can be problematic in relatively dry soils,

Conclusions

With a precipitation manipulation experiment, we illustrated a pronounced seasonal pattern of topsoil GA and GN rates in a semi-arid steppe with soil water content as main control of GA during the growing season under favorable temperature. In contrast, GN was strongly regulated by substrate supply through GA. Thus, the extent and direction of precipitation changes will ultimately determine gross N turnover and associated N availability in a changing climate. A persistent reduction of

Declaration of competing interest

The authors declare no interests of conflict.

Acknowledgements

This work was partially supported by the Chinese National Key Development Program for Basic Research [2017YFA0604802, 2016YFC0500703] and National Natural Science Foundation of China [31770526, 31872406]. X.X. acknowledge the financial support from the San Diego State University and the CSU Program for Education & Research in Biotechnology. Data sharing or any questions should contact Dr. C. H. Wang (E-mail: [email protected]). The work of Michael Dannenmann was supported by the SUSALPS

References (58)

F. Beeckman et al.
Nitrification in agricultural soils: impact, actors and mitigation
Current Opinion in Biotechnology
(2018)
G. Bengtsson et al.
Gross nitrogen mineralization-, immobilization-, and nitrification rates as a function of soil C/N ratio and microbial activity
Soil Biology and Biochemistry
(2003)
J. Braun et al.
Full N-15 tracer accounting to revisit major assumptions of N-15 isotope pool dilution approaches for gross nitrogen mineralization
Soil Biology and Biochemistry
(2018)
R. Cáceres et al.
Nitrification within composting: a review
Waste Management
(2018)
M. Dannenmann et al.
Tree girdling provides insight on the role of labile carbon in nitrogen partitioning between soil microorganisms and adult European beech
Soil Biology and Biochemistry
(2009)
D. Kou et al.
Diverse responses of belowground internal nitrogen cycling to increasing aridity
Soil Biology and Biochemistry
(2018)
W. Li et al.
Ecosystem structure, functioning and stability under climate change and grazing in grasslands: current status and future prospects
Current Opinion in Environmental Sustainability
(2018)
A. Miller et al.
Episodic rewetting enhances carbon and nitrogen release from chaparral soils
Soil Biology and Biochemistry
(2005)
M. Pansu et al.
Modelling of soil nitrogen forms after organic amendments under controlled conditions
Soil Biology and Biochemistry
(1998)
S.M. Schaeffer et al.
Soil carbon and nitrogen dynamics throughout the summer drought in a California annual grassland
Soil Biology and Biochemistry
(2017)

M. Schütt et al.

Temperature sensitivity of C and N mineralization in temperate forest soils at low temperatures

Soil Biology and Biochemistry

(2014)

C. Wang et al.

Effects of grazing exclusion on soil net nitrogen mineralization and nitrogen availability in a temperate steppe in northern China

Journal of Arid Environments

(2010)

X. Zhang et al.

Seasonal variations in nitrogen mineralization under three land use types in a grassland landscape

Acta Oecologica-International Journal of Ecology

(2008)

W.X. Zhu et al.

Temporal and spatial variations in nitrogen transformations in deciduous forest ecosystems along an urban - rural gradient

Soil Biology and Biochemistry

(2004)

Y. Bai et al.

Tradeoffs and thresholds in the effects of nitrogen addition on biodiversity and ecosystem functioning: evidence from Inner Mongolia Grasslands

Global Change Biology

(2010)

Y. Bai et al.

Primary production an rain use efficiency across a precipitation gradient on the Mongolia plateau

Ecology

(2008)

Y.F. Bai et al.

Ecosystem stability and compensatory effects in the Inner Mongolia grassland

Nature

(2004)

P. Bengtson et al.

Relieving substrate limitation-soil moisture and temperature determine gross N transformation rates

Oikos

(2005)

C.J. Bernacchi et al.

Terrestrial ecosystems in a changing environment: a dominant role for water

Annual Review of Plant Biology

(2015)

J. Bhandari et al.

Spatial and seasonal variation in rain use efficiency in semiarid grasslands of Inner Mongolia

Advances in Meteorology

(2015)

M.S. Booth et al.

Controls on nitrogen cycling in terrestrial ecosystems: a synthetic analysis of literature data

Ecological Monographs

(2005)

K. Butterbach-Bahl et al.

Soil Carbon and Nitrogen Interactions and Biosphere-Atmosphere Exchange of Nitrous Oxide and Methane

(2012)

M.A. Cregger et al.

The impact of precipitation change on nitrogen cycling in a semi-arid ecosystem

Functional Ecology

(2014)

M. Dannenmann et al.

Climate change impairs nitrogen cycling in European Beech Forests

PloS One

(2016)

M. Dannenmann et al.

Effects of forest management on soil N cycling in beech forests stocking on calcareous soils

Plant and Soil

(2006)

M.Z. Fan et al.

Spatial change trends of temperature and precipitation in China

Journal of Geo-information Science

(2011)

J. Friedl et al.

Effect of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) on N-turnover, the N₂O reductase-gene nosZ and N₂O:N₂ partitioning from agricultural soils

Scientific Reports

(2020)

F. Gerschlauer et al.

Gross nitrogen turnover of natural and managed tropical ecosystems at Mt. Kilimanjaro, Tanzania

Ecosystems

(2016)

P.M. Homyak et al.

Effects of drought manipulation on soil nitrogen cycling: a meta-analysis

Journal of Geophysical Research: Biogeosciences

(2017)

Cited by (22)

Extreme precipitation alters soil nitrogen cycling related microbial community in karst abandoned farmland
2024, Applied Soil Ecology
Precipitation varies significantly in the southwest China karst regions, with a significant increase in the number of years with abnormally low precipitation during the rainy season and longer dry periods. Soil moisture and nitrogen chemical patterns are the main limiting factors for plant growth in this region. However, there are fewer studies on the impact of extreme precipitation on soil nitrogen cycling in abandoned farmland in karst ecosystems. In this study, we investigated the effects of changes in precipitation frequency and single precipitation amount on the nitrogen-cycle related microbial community in karst abandoned farmland through a two-year precipitation manipulation experiment. Our results showed that more frequent, smaller precipitation events increased soil water content, alleviating water limitation in karst abandoned farmland and resulting in higher abundance of functional genes (nosZ, nrtABCD, gltBD, and gdhB), which accelerated soil nitrogen turnover compared to natural precipitation (Control). The changes in the gene abundance were associated with shifts in the dominant microbial taxa, such as Proteobacteria and Actinobacteria. In addition, nitrogen-cycling microbial communities exhibited resistance and resilience to extreme precipitation conditions. These findings shed light on the influence of precipitation regimes changes on soil nitrogen cycling in karst abandoned farmland, offering valuable insights for predicting the ecosystem's response to future precipitation changes.
Non-linear effects of temperature and moisture on gross N transformation rates in an Inner Mongolian grassland
2024, Catena
Understanding how soil nitrogen (N) turnover responds to temperature and soil moisture alterations is important for accurately predicting responses of soil N availability and plant productivity to global climate change. However, few studies had explored such questions under natural conditions. We investigated effects of temperature and moisture on soil gross N turnover with an annual scale field experiment in an Inner Mongolian grassland and a laboratory incubation experiment. In the field experiment, on the annual scale both gross ammonification and nitrification rates showed a hump-shaped response to temperature, with maximum rates occurring around 10 °C and 5 °C, respectively. Gross ammonification rates did not respond to soil moisture, and gross nitrification rates decreased first and then increasing with soil moisture, which the threshold was 35% water holding capacity (WHC). Totally, soil temperature explained more variation than moisture in gross ammonification (0.30 VS 0.04) and nitrification (0.24 VS 0.14) rates. On the seasonal scale, both soil temperature and moisture showed generally significant effects on gross N turnover. Grazing had no effects on soil temperature and moisture sensitivity of gross N turnover on the annual scale, but increased the sensitivity of gross ammonification to soil moisture during the spring freeze–thaw period. In the laboratory incubation experiment, gross ammonification and nitrification rates increased with the increase of temperature, although there was no difference between 20 °C and 30 °C. Gross ammonification rates reached a maximum at 50% WHC, while gross nitrification rates did not respond to soil moisture until 100% WHC. Soil temperature explained more variation than moisture in gross ammonification (0.71 VS 0.01) and nitrification (0.37 VS 0.25) rates. Our results imply that climate warming may have greater impact on gross nitrogen turnover compared to changes in rainfall, however it remains great uncertainty due to the low explanation of soil temperature and moisture.
Plant composition change mediates climate drought, nitrogen addition, and grazing effects on soil net nitrogen mineralization in a semi-arid grassland in North China
2024, Science of the Total Environment
Human activities induce alterations of the nitrogen (N) cycle, climate drought, and disturbance (e.g., livestock grazing) regimes at the global scale. Their individual, interactive, and combined effects on soil N cycling in grasslands are unclear. We investigated the N addition, drought, and grazing effects on the N mineralization, as well as their correlations with N-related variables, including the C4 species, shoot biomass (SB), root biomass (RB), plant total nitrogen (PTN), plant total carbon (PTC), soil total nitrogen (STN), soil total carbon (STC), and soil microbial N and C, during a three-year field experiment conducted in a semi-arid grassland in North China. The results showed that N addition increased the nitrate N (NO₃⁻-N) and ammonium N (NH₄⁺-N) concentrations, whereas drought decreased the NO₃⁻-N concentration because of strengthened N limitation. Pronounced temporal variation in the N mineralization occurred under seasonal drought (maxima in August and September) and under its combination with N addition and grazing (minima in August). RB and the C4 species were positively correlated, whereas STC and the NO₃⁻-N concentration were negatively correlated with the N mineralization under the combined influence of the three factors. The structural equation model showed that at the site affected by all three factors, drought indirectly increased the N mineralization by reducing the NO₃⁻-N concentration, whereas N addition and grazing did not alter the N mineralization. N addition directly increased while indirectly reduced N mineralization by increasing the NO₃⁻-N concentration. Additionally, N addition and grazing increased the C4 species and decreased the STC, consequently enhanced N mineralization. These results highlight the predominant role of drought, when combined with N addition and grazing, in controlling the N mineralization. The N supply balance in semi-arid grasslands could be stabilized in response to increased N addition, climate drought, and grazing.
Possibility of exogenous organic carbon input to increase global soil nitrogen supply potential: A meta-analysis
2023, Soil and Tillage Research
Soil nitrogen (N) mineralization is regulated by the input of exogenous organic carbon (C, ExoC) substrate via changing C availability. Although ExoC input occurs widely among global terrestrial ecosystems, it is still not clear how ExoC input affects soil gross N mineralization (GNM). Here, 265 observations from 63 peer-reviewed publications were collected for a global meta-analysis to investigate the effect and the drivers of ExoC input upon soil GNM. The results showed that ExoC input significantly increased GNM by 40.8%, and the influence depended on the types of ExoC substrate. The input of complex ExoC substrate (straw, animal manure, cellulose, etc.) increased soil GNM by 44.8%, while simple ExoC substrate (glucose, amino acids, oxalic, etc.) had no significant effect on GNM. Only in cropland the ExoC input promote the rate of soil GNM, with no significant effect found in either forest or grassland. Furthermore, the results revealed that the application rate of ExoC was the paramount factor affecting soil GNM, given their significant positive correlations. This study also emphasized that initial soil pH (i.e. soil pH before ExoC input) and pH of ExoC, rather than the change of bulk soil pH, played an important role in regulating soil GNM after the ExoC input, and both were significantly negatively correlated with GNM. In addition, soil GNM was also negatively correlated with mean annual temperature but positively related with soil total N and mean annual precipitation. The findings of this meta-analysis contribute to a comprehensive understanding of how soil N availability and cycling respond to ExoC input on a global scale. That means the factors related to rate of ExoC, soil total N, initial soil pH, the pH of ExoC, and climate factors and the interaction among above factors may affect global soil N supplying potential.
Integrated response of carbon sequestration along co-varying gradients of climate and grazing intensity in a desert steppe ecosystem
2023, Applied Soil Ecology
The interactive effects of grazing and climate on carbon (C) storage are important for the global C budget and regional C management. In a regional-scale field experiment based on multiple grazing gradients, we examined how changes in grazing intensity and climate affected the C sequestration rate and C storage at five desert steppe sites. The mean total ecosystem C storage at each site ranged from 1502 to 3728 g C m⁻² and averaged 2341 g C m⁻². The peak value of the C sequestration rate (290 g C m⁻² yr⁻¹) occurred in the light grazing intensity. The light grazing and fencing management were more beneficial to C sequestration. The rising temperature would decrease C storage in desert steppe, while rising precipitation would promote C sequestration. Soil nitrogen content plays an important role in the driving mechanism of C sequestration in desert steppe. The soil C pool, which dominated the C dynamics in desert steppe, was influenced by the changes of precipitation and grazing intensity. Grazing affects soil nitrogen content by changing the aboveground C pool. Precipitation changes may change soil C storage by influencing the aboveground C pool to change soil nitrogen content and microbial biomass. Such information improves understanding of the dynamics of C storage and sequestration in desert steppe, and is critical for improving the sustainability of grassland ecosystem services and C management.
Disruption of fungal hyphae suppressed litter-derived C retention in soil and N translocation to plants under drought-stressed temperate grassland
2023, Geoderma
Litter decomposition often represents the largest carbon (C) and nitrogen (N) input into the soil and thereby supports soil nutrition cycling function. Common mycelial networks (CMNs) can promote soil C and N trades during the litter decomposition process. However, the degree to which this promotion depends on abiotic variables, such as drought, remains unresolved. Importantly, the influence of soil fungi mycelium on the turnover of litter-derived C and N could weaken under drought if disrupts fungal hyphae. Here, we used plant litter of stable isotope dual-labeling (¹³C and ¹⁵N), experimental drought (ambient, 30%, 50%, or 70% growing season precipitation reductions), and physical disruption to soil fungal hyphae (via soil core rotation) to investigate decomposition dynamics along the soil-plant-atmosphere continuum in a temperate grassland. On average, drought significantly slowed plant litter decomposition by up to 31.8%, but undisrupted fungal hyphae accelerated litter decomposition by up to 31.7% and promoted the release of C and N from plant litter. The intactness of fungal hyphae would have divergent effects on the allocation of litter-derived C and N during decomposition under drought conditions. Intact soil fungal hyphae contributed about 47% of litter-derived C transfer into soil microbial biomass after litter decomposition, but no significant effects in the soil, plant aboveground, or CO₂ emissions, compared to hyphae disruption treatment. Undisrupted hyphae promoted approx. 82% of the turnover of litter-derived N from soil to plant and reduced content of litter-derived N in soil and N₂O emission compared to hyphae disruption. We conclude that intact networks of soil fungal hyphae are essential to maintaining litter decomposition processes under drought conditions in temperate grassland ecosystems because the fungi promote releases of carbon and nitrogen from plant litter that facilitate carbon and nitrogen cycling.

View all citing articles on Scopus

View full text

Seasonality of gross ammonification and nitrification altered by precipitation in a semi-arid grassland of Northern China

Highlights

Abstract

Section snippets

1Introduction

2.1Study site and experimental design

3.1Soil temperature (ST), soil water-filled pore space (WFPS) and soil dissolved N concentrations

4.1Gross N turnover in semi-arid steppe soils

Conclusions

Declaration of competing interest

Acknowledgements

Current Opinion in Biotechnology

Soil Biology and Biochemistry

Soil Biology and Biochemistry

Waste Management

Soil Biology and Biochemistry

Soil Biology and Biochemistry

Current Opinion in Environmental Sustainability

Soil Biology and Biochemistry

Soil Biology and Biochemistry

Soil Biology and Biochemistry

Soil Biology and Biochemistry

Journal of Arid Environments

Acta Oecologica-International Journal of Ecology

Soil Biology and Biochemistry

Tradeoffs and thresholds in the effects of nitrogen addition on biodiversity and ecosystem functioning: evidence from Inner Mongolia Grasslands

Global Change Biology

Primary production an rain use efficiency across a precipitation gradient on the Mongolia plateau

Ecology

Ecosystem stability and compensatory effects in the Inner Mongolia grassland

Nature

Relieving substrate limitation-soil moisture and temperature determine gross N transformation rates

Oikos

Terrestrial ecosystems in a changing environment: a dominant role for water

Annual Review of Plant Biology

Spatial and seasonal variation in rain use efficiency in semiarid grasslands of Inner Mongolia

Advances in Meteorology

Controls on nitrogen cycling in terrestrial ecosystems: a synthetic analysis of literature data

Ecological Monographs

Soil Carbon and Nitrogen Interactions and Biosphere-Atmosphere Exchange of Nitrous Oxide and Methane

The impact of precipitation change on nitrogen cycling in a semi-arid ecosystem

Functional Ecology

Climate change impairs nitrogen cycling in European Beech Forests

PloS One

Effects of forest management on soil N cycling in beech forests stocking on calcareous soils

Plant and Soil

Spatial change trends of temperature and precipitation in China

Journal of Geo-information Science

Effect of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) on N-turnover, the N2O reductase-gene nosZ and N2O:N2 partitioning from agricultural soils

Scientific Reports

Gross nitrogen turnover of natural and managed tropical ecosystems at Mt. Kilimanjaro, Tanzania

Ecosystems

Effects of drought manipulation on soil nitrogen cycling: a meta-analysis

Journal of Geophysical Research: Biogeosciences

Effect of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) on N-turnover, the N₂O reductase-gene nosZ and N₂O:N₂ partitioning from agricultural soils