Isotope characteristics of vegetables and wheat from conventional and organic production

• Published in: Isotopes in environmental and health studies 2005-09, Vol.41 (3), p.223-228
• Main Authors: Schmidt, Hanns-ludwig, Roßmann, Andreas, Voerkelius, Susanne, Schnitzler, Wilfried H., Georgi, Michael, Graßmann, Johanna, Zimmermann, Gerhard, Winkler, Ralf
• Format: Article
• Language: English
• Subjects: Ammonia - chemistry; Conventional production; Environmental Monitoring - methods; Food, Organic - analysis; Isotopes - analysis; Natural abundances; Nitric Acid - chemistry; Nitric Acid - metabolism; Nitrogen Isotopes - analysis; Nitrogen-15; Organic production; Oxygen Isotopes - analysis; Oxygen-18; Sulfur Isotopes - analysis; Sulphur-34; Triticum - chemistry; Triticum - growth & development; Vegetables; Vegetables - chemistry; Vegetables - growth & development; Wheat
• ISSN: 1025-6016; 1477-2639
• DOI: 10.1080/10256010500230072

Multielement isotope ratio analysis was checked for its suitability as a means for the discrimination between agricultural products from integrated/conventional or organic production, respectively. Differences were mainly found for δ 15 N-values. Paprika and tomatoes from organic production in greenhouses showed δ 15 N-values above+7 ‰, whereas corresponding products from conventional cultivation had δ 15 N-values near 0 ‰. Lettuce, onions, cabbage and Chinese cabbage from field production had δ 15 N-values in the range of+5 to+6 and+5.5 to+7.5 ‰, respectively (conventional and organic production); these overlapping differences do not permit a reliable discrimination. The same is true for wheat, showing average δ 15 N-values of+2.3±1.0 and+3.6±1.6 ‰, respectively. The unexpected relative high 15 N-enrichments of vegetables from integrated production are discussed as originating, at least partially, from 15 N-enrichment in the soil by NH 3 evaporation and denitrification.