Short-term changes in δ13C and δ15N signatures of water discharged from grazed grasslands

McTiernan, Kevin B.; Jarvis, S. C.; Allen, Deborah; Bol, Roland; Scholefield, D.

doi:10.1002/(sici)1097-0231(19990930)13:18<1803::aid-rcm718>3.0.co;2-m

Cited by 6 publications

(5 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(2000) gave no such data for dissolved organic C, and both studies were limited to a single sampling date. In addition, differing hydrological conditions and soil processes at the different sites may affect the chemical and, in consequence, the isotopic composition of the dissolved organic C (McTiernan et al . 1999).…”

Section: Resultsmentioning

confidence: 99%

Isotopic fractionation of dissolved organic carbon in shallow forest soils as affected by sorption

Kaiser

Guggenberger

Zech

2001

European J Soil Science

View full text Add to dashboard Cite

Summary Isotopic fractionation of dissolved organic carbon percolating through the soil is often interpreted as due to microbial transformation. We investigated the potential effects of sorption on the δ13C of dissolved organic C in field and laboratory experiments. We sampled the organic C in soil water at two forested sites and measured sorption with intact mineral soil and individual minerals (dolomite, ferrihydrite, goethite, and quartz). The dissolved organic C was separated into hydrophilic and hydrophobic fractions using a resin approach. The δ13C values of bulk soils, alkaline‐extractable organic C, and dissolved organic C and its fractions were measured. Hydrophilic and hydrophobic fractions in forest floor seepage water were characterized by 13C‐NMR spectroscopy. At both sites, δ13C of dissolved organic C increased with increasing depth, suggesting that decomposition contributes to the loss of the dissolved organic C. However, there was an enrichment of hydrophilic organic C in the soil solution as the water moved down the soil. The δ13C values of hydrophilic fractions were less negative than those of hydrophobic fractions. The smaller δ13C in the hydrophobic fraction was due to the large contribution of compounds derived from lignin that are depleted in 13C. As the isotope composition of both fractions of dissolved organic C did not change throughout the profile, changes in δ13C of total organic C reflected changes in the relative proportions of its hydrophilic and hydrophobic fractions. The sorption experiments with minerals and soil cores gave similar results. When dissolved organic C came into contact with mineral material, the δ13C of that remaining in solution increased due to preferential sorption of the 13C‐depleted hydrophobic fractions. Moreover, the soils released hydrophilic organic C with large δ13C values, increasing the δ13C of organic C in effluents from soil compared with that in the inflow. Thus, selective sorption of organic C fractions changes δ13C in a way that mimics metabolic transformation and decomposition.

show abstract

Section: Resultsmentioning

confidence: 99%

Isotopic fractionation of dissolved organic carbon in shallow forest soils as affected by sorption

Kaiser

Guggenberger

Zech

2001

European J Soil Science

View full text Add to dashboard Cite

show abstract

“…Stable isotope abundances of N have been used extensively to provide information on the origins and transformations of N in soils, surface waters and ground waters 3–9. It has also been demonstrated by a number of studies that a wide variety of chemical and biological processes (i.e.…”

mentioning

confidence: 99%

Using δ¹⁵N and δ¹⁸O to evaluate the sources and pathways of NO in rainfall event discharge from drained agricultural grassland lysimeters at high temporal resolutions

Granger¹,

Heaton

Bol³

et al. 2008

Rapid Comm Mass Spectrometry

Self Cite

View full text Add to dashboard Cite

The origin of NO 3− yielded in drainage from agricultural grasslands is of environmental significance and has three potential sources; (i) soil organic mater (SOM), (ii) recent agricultural amendments, and (iii) atmospheric inputs. The variation in δ15N‐NO 3− and δ18O‐NO 3− was measured from the ‘inter‐flow’ and ‘drain‐flow’ of two 1 ha drained lysimeter plots, one of which had received an application of 21 m3 of NH 4+‐N‐rich agricultural slurry, during two rainfall events. Drainage started to occur 1 month after the application of slurry. The concentrations of NO 3−‐N from the two lysimeters were comparable; an initial flush of NO 3−‐N occurred at the onset of drainage from both lysimeters before levels quickly dropped to <1 mg NO 3−‐N L−1. The isotopic signature of the δ15N‐NO 3− and δ18O‐NO 3− during the first two rainfall events showed a great deal of variation over short time‐periods from both lysimeters. Isotopic variation of δ15N‐NO 3− during rainfall events ranged between −1.6 to +5.2‰ and +0.4 to +11.1‰ from the inter‐flow and drain‐flow, respectively. Variation in the δ18O‐NO 3− ranged from +2.0 to +7.8‰ and from +3.3 to +8.4‰. No significant relationships between the δ15N‐NO 3− or δ18O‐NO 3− and flow rate were observed in most cases although δ18O‐NO 3− values indicated a positive relationship and δ15N‐NO 3− values a negative relationship with flow during event 2. Data from a bulked rainfall sample when compared with the theoretical δ18O‐NO 3− for soil microbial NO 3− indicated that the contribution of rainfall NO 3− accounted for 8% of the NO 3− in the lysimeter drainage at most. The calculated contribution of rainfall NO 3− was not enough to account for the depletion in δ15N‐NO 3− values observed during the duration of the rainfall event 2. The relationship between δ15N‐NO 3− and δ18O‐NO 3− from the drain‐flow indicated that denitrification was causing enrichment in the isotopes from this pathway. The presence of slurry seemed to cause a relative depletion in δ18O‐NO 3− in the inter‐flow and δ15N‐NO 3− in the drain‐flow compared with the zero‐slurry lysimeter. This may have been caused by increased microbial nitrification stimulated by the presence of increased NH 4+‐N. Copyright © 2008 John Wiley & Sons, Ltd.

show abstract

“…Values of δ 13 C-DOC measured on the FA fraction of soil zone water were not measured during this project, but are assumed to have values ≤ − 25 ‰ based on other studies from the UK (e.g. McTiernan et al, 1999;Palmer et al, 2001) owing to a lack of fractionation during solution. Both the LGS and the Chalk have very low matrix organic contents: ≤0.2 % by weight in the Hythe Formation (Macleod, 1998) and < 0.1 % for the White Chalk (Pacey, 1989), most of which is assumed to be highly refractory and therefore unlikely to influence the DOC in terms of its isotopic composition.…”

Section: Dic and Doc Stable Isotopesmentioning

confidence: 99%

Using environmental tracers to evaluate the preservation of palaeoclimate signals in aquifers of the London Basin, UK

Darling

Gooddy

Gulliver³

et al. 2023

Journal of Hydrology

View full text Add to dashboard Cite

Short-term changes in δ13C and δ15N signatures of water discharged from grazed grasslands

Cited by 6 publications

References 13 publications

Isotopic fractionation of dissolved organic carbon in shallow forest soils as affected by sorption

Isotopic fractionation of dissolved organic carbon in shallow forest soils as affected by sorption

Using δ¹⁵N and δ¹⁸O to evaluate the sources and pathways of NO in rainfall event discharge from drained agricultural grassland lysimeters at high temporal resolutions

Using environmental tracers to evaluate the preservation of palaeoclimate signals in aquifers of the London Basin, UK

Contact Info

Product

Resources

About

Short-term changes in δ13C and δ15N signatures of water discharged from grazed grasslands

Cited by 6 publications

References 13 publications

Isotopic fractionation of dissolved organic carbon in shallow forest soils as affected by sorption

Isotopic fractionation of dissolved organic carbon in shallow forest soils as affected by sorption

Using δ15N and δ18O to evaluate the sources and pathways of NO in rainfall event discharge from drained agricultural grassland lysimeters at high temporal resolutions

Using environmental tracers to evaluate the preservation of palaeoclimate signals in aquifers of the London Basin, UK

Contact Info

Product

Resources

About

Using δ¹⁵N and δ¹⁸O to evaluate the sources and pathways of NO in rainfall event discharge from drained agricultural grassland lysimeters at high temporal resolutions