title: The effect of manuring on cereal and pulse amino acid δ(15)N values.
abstract: Amino acid δ(15)N values of barley (Hordeum vulgare) and bread wheat (Triticum aestivum) grains and rachis and broad bean (Vicia faba) and pea (Pisum sativum) seeds, grown in manured and unmanured soil at the experimental farm stations of Rothamsted, UK and Bad Lauchstädt, Germany, were determined by GC-C-IRMS. Manuring was found to result in a consistent (15)N-enrichment of cereal grain amino acid δ(15)N values, indicating that manuring did not affect the metabolic routing of nitrogen (N) into cereal grain amino acids. The increase in cereal grain δ(15)N values with manuring is therefore due to a (15)N-enrichment in the δ(15)N value of assimilated inorganic-N. Greater variation was observed in the (15)N-enrichment of rachis amino acids with manuring, possibly due to enhanced sensitivity to changes in growing conditions and higher turnover of N in rachis cells compared to cereal grains. Total amino acid δ(15)N values of manured and unmanured broad beans and peas were very similar, indicating that the legumes assimilated N2 from the atmosphere rather than N from the soil, since there was no evidence for routing of (15)N-enriched manure N into any of the pulse amino acids. Crop amino acid δ(15)N values thus provide insights into the sources of N assimilated by non N2-fixing and N2-fixing crops grown on manured and unmanured soils, and reveal an effect of manure on N metabolism in different crop species and plant parts.
authors.affiliation: Organic Geochemistry Unit, Biogeochemistry Research Centre, School of Chemistry, University of Bristol, Bristol, UK.
authors.forename: Amy K
authors.initials: AK
authors.lastname: Styring
authors.affiliation: School of Archaeology, 36 Beaumont Street, University of Oxford, Oxford, UK.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Fraser
authors.affiliation: School of Archaeology, 36 Beaumont Street, University of Oxford, Oxford, UK.
authors.forename: Amy
authors.initials: A
authors.lastname: Bogaard
authors.affiliation: Organic Geochemistry Unit, Biogeochemistry Research Centre, School of Chemistry, University of Bristol, Bristol, UK. Electronic address: R.P.Evershed@bristol.ac.uk.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Evershed
mesh_terms: D000383:Agriculture / Q000379:methods*; D000596:Amino Acids / Q000032:analysis* / Q000378:metabolism; D002523:Edible Grain / Q000737:chemistry* / Q000378:metabolism; D001467:Hordeum / Q000737:chemistry / Q000378:metabolism; D008372:Manure; D018532:Pisum sativum / Q000737:chemistry / Q000378:metabolism; D014908:Triticum / Q000737:chemistry / Q000378:metabolism; D031307:Vicia faba / Q000737:chemistry / Q000378:metabolism
chemical_list: D000596:Amino Acids; D008372:Manure
keywords: Amino acids; Hordeum vulgare; Manure; Nitrogen; Pisum sativum; Triticum aestivum; Vicia faba; δ(15)N values