Vario el 3 c h n analyser

Total organic carbon (TOC) and total nitrogen (TN) contents of the soil samples were determined in triplicate by dry combustion using a Vario EL III C/H/N analyser (Elementar, Hanau, Germany). Since the carbonate concentration of the soils was negligible (<2%), the total C concentration measured was considered to represent TOC.

Control and flooded plants were harvested, and tillers and spikes number recorded, in the twelfth day of exposition to flooding in the corresponding developmental stages. Shoots and roots were separated, and both fresh and dry weight were measured. Samples from fully expanded leaves for molecular analysis were immediately frozen and stored at − 80 °C. Macro- (C, N, P, Mg, S, K and Ca) and micro-nutrients (Mn, Zn and Na) concentrations in the dry roots and leaves were measured using a sector field high-resolution mass spectrometer (HR)-ICP-MS (Element 2, Thermo Fisher Scientific, Germany). Several edaphic parameters were measured in the soil samples. Total organic carbon (TOC) and total nitrogen (TN) contents were measured in triplicate by dry combustion using a Vario EL III C/H/N analyser (Elementar, Hanau, Germany). Plant available P (PDL) was extracted from fresh soil using the double lactate extraction method (1:50 w/v, pH 3.6, 1.5 h; Riehm^{50 (link)}), and the extracted P was quantified colorimetrically using the molybdenum blue method^{51 (link)}. Soil Mn, Ca, Na, K, and Mg concentrations were determined with an inductively coupled plasma-optical emission spectrometry-ICP-OES (ICP-iCAP 6300 DUO, ThermoFisher Scientific, Germany).

Soil carbon (C) and nitrogen (N) contents were determined by dry combustion in triplicate using a Vario EL III C/H/N analyser (Elementar, Hanau, Germany). Since the carbonate concentration of the soils was negligible (<2%), the total C concentration measured was considered to represent total organic carbon (TOC). Available soil phosphorus was determined after extraction with double lactate (pH 3.6, 90 min; [27 ]) using the molybdenium blue method [28 (link)]. Gravimetric soil moisture contents were determined using a fully automatic moisture analyzer (Kern DBS60–3, Kern & Sohn GmbH, Germany). Soil pH was measured with a pH electrode (Mettler Toledo InLab Expert Pro-ISM) after shaking the soil for 1 h in 0.01 M CaCl₂ (1:2.5 w/v).
At the time of soil sampling in June 2012, the average gravimetric soil moisture was 7.7% in the drought and 15.1% in the control samples and, in September, 6.7% in the drought and 11.1% in the control samples (Figure S2). Soil properties were comparable between seasons, plant community compositions and drought or control treatments. In addition, TOC increased from June to September, and P availability was higher in plots with drought compared to control treatment (Table S3).