Determination of C and N Concentrations
To determine TN and TC concentrations, dried soil samples were ground to powder in a mortar to pass through a 100-mesh sieve. C and N analyses were performed on a Flash EA 1112 Series NC Analyzer(Italy). Organic C concentrations were also determined using the NC Analyzer after inorganic C as CO2 was removed by adding 1:1 HCl and oven dried to a constant weight