Abstract
The proportional contribution of atmospheric N2 to the N nutrition of lupin (P atm) was estimated in a field experiment following addition of NH4Cl of KNO3 to unconfined microplots (1.5 m2) at 2.5 g N m-2 (10 atom% 15N). The integrated 15N enrichment, or ‘mean pool abundance’, of nitrate extracted from 0- to 15-cm samples taken under the lupin crop on eight occasion between 28 and 190 days after sowing was used as the reference criterion to estimate P atm by the 15N-isotope dilution technique. Estimates of P atm were similar to those obtained using canola as a non-fixing reference plant, but were higher than estimates obtained using a yield-dependent model. Use of ‘mean pool abundance’ obviates the need for a non-fixing reference plant, and the frequent sampling and isotope-ratio analysis of the legume biomass required with the yield-dependent model is unnecessary. However, further work is needed to validate a sampling strategy commensurate with the growth of the legume roots.
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References
Barraclough D (1991) The use of mean pool abundances to interpret 15N tracer experiments. I. Theory. Plant Soil 131:89–96
Boddey RM, Victoria RL (1986) Estimation of biological nitrogen fixation associated with Brachiaria and Paspalum grasses using 15N labelled organic matter and fertilizer. Plant Soil 90:265–292
Boddey RM, Urquiaga S, Neves MCP, Suhet AR, Peres JR (1990) Quantification of the contribution of N2 fixation to field-grown grain legumes — a strategy for the practical application of the 15N isotope dilution technique. Soil Biol Biochem 22:649–655
Boddey RM, de Oliveira OC, Alves BJR, Urquiaga S (1995) Field application of the 15N isotope dilution technique for the reliable quantification of plant-associated biological nitrogen fixation. Fert Res 42:77–87
Bremer E, Gehlen H, Swerhone GDW, van Kessel C (1993) Assessment of reference crops for the quantification of N2 fixation using natural and enriched levels of 15N abundance. Soil Biol Biochem 25:1197–1202
Chalk PM (1985) Estimation of N2 fixation by isotope dilution: an appraisal of techniques involving 15N enrichment and their application. Soil Biol Biochem 17:389–410
Chalk PM, Douglas LA, Buchanan SA (1983) Use of 15N enrichment of soil mineralizable N as a reference for isotope dilution measurements of biologically fixed nitrogen. Can J Microbiol 29:1046–1052
Chiu C-Y, Yoshida T (1989) Evaluation of N2 fixation by applying 15N labeled plant material and ammonium sulfate. Soil Sci Plant Nutr 35:651–657
Danso SKA, Hardarson G, Zapata F (1993) Misconceptions and practical problems in the use of 15N soil enrichment techniques for estimating N2 fixation. Plant Soil 152:25–52
Fried M, Danso SKA, Zapata F (1983) The methodology of measurement of N2 fixation by nonlegumes as inferred from field experiments with legumes. Can J Microbiol 29:1053–1062
Hamilton SD, Smith CJ, Chalk PM, Hopmans P (1992) A model based on measurement of soil and plant 15N enrichment to estimate N2 fixation by soybean (Glycine max L. Merrill) grown in pots. Soil Biol Biochem 24:71–78
La Favre JS, Focht DD (1983) Comparison of N2 fixation and yields in Cajanus cajan between hydrogenase-positive and hydrogenase-negative Rhizobia by in situ acetylene reduction assays and direct 15N partitioning. Plant Physiol 72:971–977
McAuliffe C, Chamblee DS, Uribe-Arango H, Woodhouse WW Jr (1958) Influence of inorganic nitrogen on nitrogen fixation by legumes as revealed by 15N. Agron J 50:334–337
Pareek RP, Ladha JK, Watanabe I (1990) Estimating N2 fixation by Sesbania rostrata and S. cannabina (syn. S. aculeata) in lowland rice soil by the 15N dilution method. Biol Fertil Soils 10:77–88
Rarivoson G, Ladha JK (1992) Isotope 15N enrichment of soil-ammonium N as a reference to estimate N2 fixation by stem and root-inoculated S. rostrata. Biol Fertil Soils 13:74–78
Smith CJ, Chalk PM, Hamilton SD, Hopmans P (1992) Estimating N2 fixation by field-grown lupins (Lupinus angustifolius L.) using siol and plant 15N enrichment. Biol Fertil Soils 13:235–241
Witty JF (1983) Estimating N2-fixation in the field using 15N-labelled fertilizer: some problems and solutions. Soil Biol Biochem 15:631–639
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Chalk, P.M., Smith, C.J., Hopmans, P. et al. A yield-independent, 15N-isotope dilution method to estimate legume symbiotic dependence without a non-N2-fixing reference plant. Biol Fertil Soils 23, 196–199 (1996). https://doi.org/10.1007/BF00336063
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DOI: https://doi.org/10.1007/BF00336063