Short-range spatial variability of soil δ15N natural abundance – effects on symbiotic N2-fixation estimates in pea

Lars Holdensen, Henrik Hauggaard-Nielsen, Erik Steen Jensen

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

The δ15N natural abundance (‰) of the total soil N pool varies at the landscape level, but knowledge on short-range variability and consequences for the reliability of isotopic methods are poorly understood. The short-range spatial variability of soil δ15N natural abundance as revealed by the 15N abundance in spring barley and N2-fixing pea was measured within the 0.15-4 m scale at flowering and at maturity. The short-range spatial variability of soil δ15N natural abundance and symbiotic nitrogen fixation were high at both growth stages. Along a 4-m row, the δ15N natural abundance in barley reference plants varied up to 3.9 ‰, and sometimes this variability was observed even between plants grown only 30 cm apart. The δ15N natural abundance in pea varied up to 1.4  ‰ within the 4-m row. The estimated percentage of nitrogen derived from the atmosphere (%Ndfa) varied from 73-89% at flowering and from 57-95% at maturity. When increasing the sampling area from 0.01 m2 (single plants) and up to 0.6 m2 (14 plants) the %Ndfa coefficient of variation (CV) declined from 5 to 2% at flowering and from 12 to 2% at maturity. The implications of the short-range variability in δ15N natural-abundance are that estimates of symbiotic N2-fixation can be obtained from the natural abundance method if at least half a square meter of crop and reference plants is sampled for the isotopic analysis. In fields with small amounts of representative reference crops (weeds) it might be necessary to sow in reference crop species to secure satisfying N2-fixation estimates.

OriginalsprogEngelsk
TidsskriftPlant and Soil
Vol/bind298
Udgave nummer1-2
Sider (fra-til)265-272
ISSN0032-079X
DOI
StatusUdgivet - 2007
Udgivet eksterntJa

Citer dette

@article{32c013136cbb4693907a8f620c72d23a,
title = "Short-range spatial variability of soil δ15N natural abundance – effects on symbiotic N2-fixation estimates in pea",
abstract = "The δ15N natural abundance (‰) of the total soil N pool varies at the landscape level, but knowledge on short-range variability and consequences for the reliability of isotopic methods are poorly understood. The short-range spatial variability of soil δ15N natural abundance as revealed by the 15N abundance in spring barley and N2-fixing pea was measured within the 0.15-4 m scale at flowering and at maturity. The short-range spatial variability of soil δ15N natural abundance and symbiotic nitrogen fixation were high at both growth stages. Along a 4-m row, the δ15N natural abundance in barley reference plants varied up to 3.9 ‰, and sometimes this variability was observed even between plants grown only 30 cm apart. The δ15N natural abundance in pea varied up to 1.4  ‰ within the 4-m row. The estimated percentage of nitrogen derived from the atmosphere ({\%}Ndfa) varied from 73-89{\%} at flowering and from 57-95{\%} at maturity. When increasing the sampling area from 0.01 m2 (single plants) and up to 0.6 m2 (14 plants) the {\%}Ndfa coefficient of variation (CV) declined from 5 to 2{\%} at flowering and from 12 to 2{\%} at maturity. The implications of the short-range variability in δ15N natural-abundance are that estimates of symbiotic N2-fixation can be obtained from the natural abundance method if at least half a square meter of crop and reference plants is sampled for the isotopic analysis. In fields with small amounts of representative reference crops (weeds) it might be necessary to sow in reference crop species to secure satisfying N2-fixation estimates.",
author = "Lars Holdensen and Henrik Hauggaard-Nielsen and Jensen, {Erik Steen}",
year = "2007",
doi = "10.1007/s11104-007-9367-5",
language = "English",
volume = "298",
pages = "265--272",
journal = "Plant and Soil",
issn = "0032-079X",
publisher = "Springer Netherlands",
number = "1-2",

}

Short-range spatial variability of soil δ15N natural abundance – effects on symbiotic N2-fixation estimates in pea. / Holdensen, Lars; Hauggaard-Nielsen, Henrik; Jensen, Erik Steen.

I: Plant and Soil, Bind 298, Nr. 1-2, 2007, s. 265-272.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Short-range spatial variability of soil δ15N natural abundance – effects on symbiotic N2-fixation estimates in pea

AU - Holdensen, Lars

AU - Hauggaard-Nielsen, Henrik

AU - Jensen, Erik Steen

PY - 2007

Y1 - 2007

N2 - The δ15N natural abundance (‰) of the total soil N pool varies at the landscape level, but knowledge on short-range variability and consequences for the reliability of isotopic methods are poorly understood. The short-range spatial variability of soil δ15N natural abundance as revealed by the 15N abundance in spring barley and N2-fixing pea was measured within the 0.15-4 m scale at flowering and at maturity. The short-range spatial variability of soil δ15N natural abundance and symbiotic nitrogen fixation were high at both growth stages. Along a 4-m row, the δ15N natural abundance in barley reference plants varied up to 3.9 ‰, and sometimes this variability was observed even between plants grown only 30 cm apart. The δ15N natural abundance in pea varied up to 1.4  ‰ within the 4-m row. The estimated percentage of nitrogen derived from the atmosphere (%Ndfa) varied from 73-89% at flowering and from 57-95% at maturity. When increasing the sampling area from 0.01 m2 (single plants) and up to 0.6 m2 (14 plants) the %Ndfa coefficient of variation (CV) declined from 5 to 2% at flowering and from 12 to 2% at maturity. The implications of the short-range variability in δ15N natural-abundance are that estimates of symbiotic N2-fixation can be obtained from the natural abundance method if at least half a square meter of crop and reference plants is sampled for the isotopic analysis. In fields with small amounts of representative reference crops (weeds) it might be necessary to sow in reference crop species to secure satisfying N2-fixation estimates.

AB - The δ15N natural abundance (‰) of the total soil N pool varies at the landscape level, but knowledge on short-range variability and consequences for the reliability of isotopic methods are poorly understood. The short-range spatial variability of soil δ15N natural abundance as revealed by the 15N abundance in spring barley and N2-fixing pea was measured within the 0.15-4 m scale at flowering and at maturity. The short-range spatial variability of soil δ15N natural abundance and symbiotic nitrogen fixation were high at both growth stages. Along a 4-m row, the δ15N natural abundance in barley reference plants varied up to 3.9 ‰, and sometimes this variability was observed even between plants grown only 30 cm apart. The δ15N natural abundance in pea varied up to 1.4  ‰ within the 4-m row. The estimated percentage of nitrogen derived from the atmosphere (%Ndfa) varied from 73-89% at flowering and from 57-95% at maturity. When increasing the sampling area from 0.01 m2 (single plants) and up to 0.6 m2 (14 plants) the %Ndfa coefficient of variation (CV) declined from 5 to 2% at flowering and from 12 to 2% at maturity. The implications of the short-range variability in δ15N natural-abundance are that estimates of symbiotic N2-fixation can be obtained from the natural abundance method if at least half a square meter of crop and reference plants is sampled for the isotopic analysis. In fields with small amounts of representative reference crops (weeds) it might be necessary to sow in reference crop species to secure satisfying N2-fixation estimates.

U2 - 10.1007/s11104-007-9367-5

DO - 10.1007/s11104-007-9367-5

M3 - Journal article

VL - 298

SP - 265

EP - 272

JO - Plant and Soil

JF - Plant and Soil

SN - 0032-079X

IS - 1-2

ER -