Can δ15N in lettuce tissues reveal the use of synthetic nitrogen fertiliser in organic production?

Abstract

The findings of the study suggest that the δ(15)N value of lettuce tissues could be used as a rough marker to reveal the history of nitrogen fertilisation, but only in the case of single fertiliser application. However, if the difference in δ(15)N between the applied synthetic and organic nitrogen fertilisers was > 9.1 ‰, the detection of split and combined usage of the fertilisers would have greater discriminatory power.

Stable carbon and nitrogen isotopes as a potential tool to differentiate pork from organic and conventional systems

“…21 Besides the C isotopic ratio, the measurement of 15 N values is another way to differentiate organic farm products from conventional products. Chemical fertilisers have lower 15 N values as compared to organic fertilisers, so organic agro-products which strictly avoid synthetic fertilisers were observed to possess higher 15 N values than those determined in conventional products. 22 Considering the increasing concern regarding organic pork, the development of an effective and reliable method is of great significance to assess differences between organic and conventional pork.…”

“…The C and N stable isotope composition of each sample was measured in the same run. Nitrogen and carbon isotope data were reported in -notation in a unit of per thousands (‰) relative to the accepted international standards; 13 C‰ relative to Vienna Pee Dee Belimnite (VPDB) and 15 N‰ relative to atmospheric AIR. The delta values were calculated as: x = (R samp /R ref − 1) × 1000, where x is the stable isotope composition of the sample expressed in delta unit (‰, per thousands) relative to the reference material; and R samp and R ref are the absolute isotope ratio of the sample and reference material, respectively.…”

“…and IAEA-CH-6 (Sucrose) for 13 C value; USGS43 (Indian Human Hair) and USGS40 (L-glutamic acid) for 15 N value. The analytical precision was 0.15‰ for both C and N.…”

“…Recently, there have been many reports on the application of stable isotopes to identify the authenticity of food, including oil, 12,13 milk 7,14 and vegetables. 15,16 In recent years, several studies have been reported in which meat quality was distinguished by using the stable isotope technique. 17 -19 The carbon (C) and nitrogen (N) isotopic compositions of animal tissue have unique and typical characteristics.…”

Applying Determined Ratios of Stable Isotopes Ratios in Selected Elements to Evaluate Authenticity of Organically Grown Products

“…Na zawartość azotu w roślinie wpływa zawartość azotu w glebie, a ta z kolei jest powiązana z zastosowanym nawożeniem [8,23,27,28]. Ilość zastosowanego nawozu również wpływała na wartość δ 15 N, co wykazali Georgi i wsp.…”