Fig. 1 Effect of thawing and agriculture practices on denitrifying rate (DR) in soil slurries of conventional till continuous barley (CT–C) and no-tillage–barley–red clover rotation (NT–R) treatments. Agricultural practices and freeze treatments indicate significant differences (P < 0.0005 and 0.05); interaction between treatments was not significant. Vertical bars represent standard error of four replicates