Figure 3. Ryegrass growth responses to thermally treated and leached chars: contrasts between treatments.

Simultaneous confidence intervals (95%) for ryegrass aboveground biomass (A) and belowground biomass (B) responses to water washed (striped bars) and convection heated (grey bars) biochar (Experiment 2). BC, biochar (unwashed); BC (Mix), biochar, mixed; BC (Top), biochar, top-dressing. Abbreviations for heating (Heat) and washing (WW) treatments are defined in the methods. Significant differences between treatment means are denoted with asterisks (P = < 0.05*, < 0.01**, 0.001***).