Total seed N% was measured using elemental analyzer (Vario EL; Elementar analyse system).
Nitrogen and carbon concentrations of the samples were analyzed by an elemental analyzer (EA1108, Carlo Erba, Torino, Italy).
Samples were analyzed for C and N on a CE Instruments model NC2100 elemental analyzer.
Retained N was measured using an elemental analyzer, as described above.
Briefly, total C and N were determined with a combustion elemental analyzer.
Total N and C were determined using an Elemental Analyzer (Leco Truspec, St. Joseph, MI, USA).
The line is also connected to an elemental analyzer.
Available NH4 + and total organic C (TOC) were determined using an Elemental Analyzer (Leco Truspec, St. Joseph, MI, USA).
Soil total carbon (TC, %) and TN were measured using a vario MACRO cube elemental analyzer (Elementar, Germany).
Total carbon, nitrogen and sulfur (total C, N and S) were measured in sediments using a Thermo Scientific Flash2000 Organic Elemental Analyzer (Waltham, MA, USA).
Total C, N, H, and O were measured using a Delta V Isotope Ratio Mass Spectrometer (Thermo Scientific, Germany) coupled to a Carlo Erba NC2500 Elemental Analyzer (Italy).
