2.5. Chemical properties of soil
In 1 mm of dried, sieved soil samples, the following parameters were determined: pH – potentiometrically, in the suspension of soil and water as well as soil and 1 mol∙dm-3 solution of KCl (soil:solution = 1:2.5) and electrical conductivity (EC) – conductometrically. The total carbon (CTot) and total nitrogen (NTot) contents were determined with a CNS analyser Vario MAX Cube (Elementar, Langenselbold, Germany) (Elementar Analysensysteme, 2013). Bioavailable trace elements were extracted from the soil for 2 hours with a 0.01 mol dm-3 solution of CaCl2 (soil:solution = 1:10) (Houba et al., 2000). In the obtained extracts, the studied elements were determined by inductively coupled plasma optical emission spectrometry (ICP-OES, Perkin Elmer Optima 7300 DV, Waltham, USA) (Oleszczuk et al., 2007).