Microbial biomass C (B_C) in conservative and conventional systems in 2014 and 2015. CWC: chemical weed control, MWC: permanent grass cover, LL: land levelling, US: undisturbed soil, CON: conventional farming, ORG: organic farming. Bars represent standard deviation (n = 3). For each pair of treatments, *, ** and *** indicate significant differences between treatments at 0.05, 0.01 and 0.005 significance level, respectively (T test).