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.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Androsoff GL, vanKessel C, Pennock DJ (1995) Landscape-scale estimates of dinitrogen fixation by Pisum Sativum by 15N natural abundance and enriched isotope dilution. Proceedings of the Twenty-Seventh Annual Conference of the Agronomy Society of New Zealand 20:33–40
Bedard-Haughn A, van Groenigen JW, van Kessel C (2003) Tracing 15N through landscapes: potential uses and precautions. J Hydrol 272:175–190
Bremer E, vanKessel C (1990) Appraisal of the N-15 natural-abundance method for quantifying dinitrogen fixation. Soil Sci Soc Am J 54:404–411
Bremer E, Rennie RJ, Rennie DA (1998) Dinitrogen fixation of lentil and field pea and fababean under dryland conditions. Can J Soil Sci 68:553–562
Chalk PM (1998) Dynamics of biologically fixed N in legume–cereal rotations: a review. Aust J Agric Res 49:303–316
Eriksen J, Hogh-Jensen H (1998) Variations in the natural abundance of N-15 in ryegrass/white clover shoot material as influenced by cattle grazing. Plant Soil 205:67–76
Gathumbi SM, Cadisch G, Giller KE (2002) 15N natural abundance as a tool for assessing N2-fixation of herbaceous, shrub and tree legumes in improved fallows. Soil Biol Biochem 34:1059–1071
Hauggaard-Nielsen H, Jensen E (2005) Facilitative Root Interactions in Intercrops. Plant Soil 274:237–250
Hauggaard–Nielsen H, Ambus P, Jensen ES (2001) Temporal and spatial distribution of roots and competition for nitrogen in pea−barley intercrops – a field study employing P-32 technique. Plant Soil 236:63–74
Hauggaard-Nielsen H, Ambus P, Jensen ES (2003) The comparison of nitrogen use and leaching in sole cropped versus intercropped pea and barley. Nutr Cycl Agroecosyst 65:289–300
Herridge DF, Danso SKA (1995) Enhancing crop legume N2 fixation through selection and breeding. Plant Soil 174:51–82
Lancashire PD, Bleiholder H, Vandenboom T, Langeluddeke P, Stauss R, Weber E, Witzenberger A (1991) A uniform decimal code for growth-stages of crops and weeds. Ann Appl Biol 119:561–601
Pate JS, Unkovich MJ, Armstrong EL, Sanford P (1994) Selection of reference plants for 15N natural abundance assessment of N2 fixation by crop and pasture legumes in South-West Australia. Aust J Agric Res 45:133–147
Peoples MB, Herridge DF, Ladha JK (1995) Biological nitrogen fixation: An efficient source of nitrogen for sustainable agricultural production? Plant Soil 174:3–28
SAS (1990) SAS procedure guide. SAS Institute.
Shearer G, Kohl DH (1986) N2-fixation in field settings – Estimations based on natural 15N abundance. Aust J Plant Physiol 13:699–756
Stevenson FC, Knight JD, vanKessel C (1995) Dinitrogen fixation in pea: Controls at the landscape- and micro-scale. Soil Sci Soc Am J 59:1603–1611
Unkovich MJ, Pate JS, Sanford P, Armstrong EL (1994) Potential precision of the delta 15N natural-abundance method in field estimates of nitrogen-fixation by crop and pasture legumes in South-west Australia. Aust J Agric Res 45:119–132
Walley F, Fu GM, van Groenigen JW, van Kessel C (2001) Short-range spatial variability of nitrogen fixation by field-grown chickpea. Soil Sci Soc Am J 65:1717–1722
Acknowledgement
The European Commission Contract No. FOOD-CT-2004-506223 New Strategies to Improve Grain Legumes for Food and Feed (GLIP) funded this study.
Author information
Authors and Affiliations
Corresponding author
Additional information
Responsible Editor: R.M. Boddey.
Rights and permissions
About this article
Cite this article
Holdensen, L., Hauggaard-Nielsen, H. & Jensen, E.S. Short-range spatial variability of soil δ15N natural abundance – effects on symbiotic N2-fixation estimates in pea. Plant Soil 298, 265–272 (2007). https://doi.org/10.1007/s11104-007-9367-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11104-007-9367-5