Visualizing small-scale subsurface NH3 and pH dynamics surrounding nitrogen fertilizer granules and impacts on nitrification activity (2024)

Merls, T., Sedlacek, C., Pjevac, P., Fuchslueger, L., Sandén, T., Spiegel, H., Koren, K. (2024). Visualizing small-scale subsurface NH3 and pH dynamics surrounding nitrogen fertilizer granules and impacts on nitrification activity. Soil Biology and Biochemistry, 189, [109273]. https://doi.org/10.1016/j.soilbio.2023.109273

Merls, Theresa ; Sedlacek, Christopher ; Pjevac, Petra et al. / Visualizing small-scale subsurface NH3 and pH dynamics surrounding nitrogen fertilizer granules and impacts on nitrification activity. in: Soil Biology and Biochemistry. 2024 ; Band 189.

@article{caa7a3b450e4490faa112ecbdefd842d,

title = "Visualizing small-scale subsurface NH3 and pH dynamics surrounding nitrogen fertilizer granules and impacts on nitrification activity",

abstract = "In agricultural soils, nitrogen (N) fertilizer is typically applied as ammonium salts or urea, and undergoes microbially mediated oxidation. However, insights regarding substrate concentrations nitrifiers are exposed to in the zones immediately surrounding N fertilizer granules remain unexamined, as well as how this affects the activity or inhibition of nitrifier groups adapted to different ranges of ammonia (NH3) concentrations. To examine millimeter scale changes in soil chemistry after sub-surface fertilizer granule application with high spatiotemporal resolution, we applied a newly developed NH3 and pH planar optical sensor (optode) system. With this system, we visualized in situ subsurface NH3 production, diffusion, and associated pH shifts in an agricultural soil following the application (from 5 min up to 65.5 h) of ammonium chloride (NH4Cl) or urea granules in a laboratory study. Ammonia from both NH4Cl and urea granules diffused up to 1.5 and 2 cm and reached maximum concentrations of >49 and >130 ppmv, respectively. Spatially informed destructive subsampling (0.5–2 cm from granules) revealed that nitrate accumulation was greatest closest (0.5–1 cm) to the ammonium chloride granules, while nitrite was not detected. In contrast, urea application resulted in both nitrite and nitrate accumulation, with the highest concentrations detected furthest (1.5–2 cm) from urea granules. Urea hydrolysis also caused a significant localized pH increase, while ammonium chloride caused a circular elevated pH zone migrating outwards leaving a decreased pH at the center. Transcription of the ammonia-oxidizing bacterial amoA gene was highest in areas furthest (1.5–2 cm) from the urea granules, while there were no significant differences in amoA transcription with increasing distance from the NH4Cl granules. Ammonia-oxidizing archaea and comammox amoA transcripts were not detected. This study is the first to directly visualize small-scale subsurface changes in NH3 concentration and pH after fertilizer granule application and relate these to nitrification activity.",

keywords = "ammonia, pH, nitrification, optopedes, urea, ammonia oxidizing bacteria, Ammonia, Urea, Nitrification, Optodes, Ammonia oxidizing bacteria",

author = "Theresa Merls and Christopher Sedlacek and Petra Pjevac and Lucia Fuchslueger and Taru Sand{\'e}n and Heide Spiegel and Klaus Koren and Andrew Giguere",

note = "Publisher Copyright: {\textcopyright} 2023 The Authors",

year = "2024",

month = feb,

day = "1",

doi = "10.1016/j.soilbio.2023.109273",

language = "English",

volume = "189",

journal = "Soil Biology and Biochemistry",

issn = "0038-0717",

publisher = "PERGAMON-ELSEVIER SCIENCE LTD",

}

Merls, T, Sedlacek, C, Pjevac, P, Fuchslueger, L, Sandén, T, Spiegel, H, Koren, K 2024, 'Visualizing small-scale subsurface NH3 and pH dynamics surrounding nitrogen fertilizer granules and impacts on nitrification activity', Soil Biology and Biochemistry, Jg. 189, 109273. https://doi.org/10.1016/j.soilbio.2023.109273

Visualizing small-scale subsurface NH3 and pH dynamics surrounding nitrogen fertilizer granules and impacts on nitrification activity. / Merls, Theresa; Sedlacek, Christopher; Pjevac, Petra et al.

in: Soil Biology and Biochemistry, Band 189, 109273, 01.02.2024.

Veröffentlichungen: Beitrag in Fachzeitschrift › Artikel › Peer Reviewed

TY - JOUR

T1 - Visualizing small-scale subsurface NH3 and pH dynamics surrounding nitrogen fertilizer granules and impacts on nitrification activity

AU - Merls, Theresa

AU - Sedlacek, Christopher

AU - Pjevac, Petra

AU - Fuchslueger, Lucia

AU - Sandén, Taru

AU - Spiegel, Heide

AU - Koren, Klaus

AU - Giguere, Andrew

N1 - Publisher Copyright:© 2023 The Authors

PY - 2024/2/1

Y1 - 2024/2/1

N2 - In agricultural soils, nitrogen (N) fertilizer is typically applied as ammonium salts or urea, and undergoes microbially mediated oxidation. However, insights regarding substrate concentrations nitrifiers are exposed to in the zones immediately surrounding N fertilizer granules remain unexamined, as well as how this affects the activity or inhibition of nitrifier groups adapted to different ranges of ammonia (NH3) concentrations. To examine millimeter scale changes in soil chemistry after sub-surface fertilizer granule application with high spatiotemporal resolution, we applied a newly developed NH3 and pH planar optical sensor (optode) system. With this system, we visualized in situ subsurface NH3 production, diffusion, and associated pH shifts in an agricultural soil following the application (from 5 min up to 65.5 h) of ammonium chloride (NH4Cl) or urea granules in a laboratory study. Ammonia from both NH4Cl and urea granules diffused up to 1.5 and 2 cm and reached maximum concentrations of >49 and >130 ppmv, respectively. Spatially informed destructive subsampling (0.5–2 cm from granules) revealed that nitrate accumulation was greatest closest (0.5–1 cm) to the ammonium chloride granules, while nitrite was not detected. In contrast, urea application resulted in both nitrite and nitrate accumulation, with the highest concentrations detected furthest (1.5–2 cm) from urea granules. Urea hydrolysis also caused a significant localized pH increase, while ammonium chloride caused a circular elevated pH zone migrating outwards leaving a decreased pH at the center. Transcription of the ammonia-oxidizing bacterial amoA gene was highest in areas furthest (1.5–2 cm) from the urea granules, while there were no significant differences in amoA transcription with increasing distance from the NH4Cl granules. Ammonia-oxidizing archaea and comammox amoA transcripts were not detected. This study is the first to directly visualize small-scale subsurface changes in NH3 concentration and pH after fertilizer granule application and relate these to nitrification activity.

AB - In agricultural soils, nitrogen (N) fertilizer is typically applied as ammonium salts or urea, and undergoes microbially mediated oxidation. However, insights regarding substrate concentrations nitrifiers are exposed to in the zones immediately surrounding N fertilizer granules remain unexamined, as well as how this affects the activity or inhibition of nitrifier groups adapted to different ranges of ammonia (NH3) concentrations. To examine millimeter scale changes in soil chemistry after sub-surface fertilizer granule application with high spatiotemporal resolution, we applied a newly developed NH3 and pH planar optical sensor (optode) system. With this system, we visualized in situ subsurface NH3 production, diffusion, and associated pH shifts in an agricultural soil following the application (from 5 min up to 65.5 h) of ammonium chloride (NH4Cl) or urea granules in a laboratory study. Ammonia from both NH4Cl and urea granules diffused up to 1.5 and 2 cm and reached maximum concentrations of >49 and >130 ppmv, respectively. Spatially informed destructive subsampling (0.5–2 cm from granules) revealed that nitrate accumulation was greatest closest (0.5–1 cm) to the ammonium chloride granules, while nitrite was not detected. In contrast, urea application resulted in both nitrite and nitrate accumulation, with the highest concentrations detected furthest (1.5–2 cm) from urea granules. Urea hydrolysis also caused a significant localized pH increase, while ammonium chloride caused a circular elevated pH zone migrating outwards leaving a decreased pH at the center. Transcription of the ammonia-oxidizing bacterial amoA gene was highest in areas furthest (1.5–2 cm) from the urea granules, while there were no significant differences in amoA transcription with increasing distance from the NH4Cl granules. Ammonia-oxidizing archaea and comammox amoA transcripts were not detected. This study is the first to directly visualize small-scale subsurface changes in NH3 concentration and pH after fertilizer granule application and relate these to nitrification activity.

KW - ammonia

KW - pH

KW - nitrification

KW - optopedes

KW - urea

KW - ammonia oxidizing bacteria

KW - Ammonia

KW - Urea

KW - Nitrification

KW - Optodes

KW - Ammonia oxidizing bacteria

UR - http://www.scopus.com/inward/record.url?scp=85183115034&partnerID=8YFLogxK

U2 - 10.1016/j.soilbio.2023.109273

DO - 10.1016/j.soilbio.2023.109273

M3 - Article

VL - 189

JO - Soil Biology and Biochemistry

JF - Soil Biology and Biochemistry

SN - 0038-0717

M1 - 109273

ER -

Merls T, Sedlacek C, Pjevac P, Fuchslueger L, Sandén T, Spiegel H et al. Visualizing small-scale subsurface NH3 and pH dynamics surrounding nitrogen fertilizer granules and impacts on nitrification activity. Soil Biology and Biochemistry. 2024 Feb 1;189:109273. Epub 2023 Dez 18. doi: 10.1016/j.soilbio.2023.109273