Fig. 4. Transfer of Cu (A) and Pb (B) to ryegrass according to total (shoot concentration/pseudo-total concentration; transfer co-efficient) pore water (shoot concentration/pore
water concentration; bioconcentration factor) (S = untreated soil, S +GWC= soil plus green waste compost, S + BC = soil plus biochar and S +GWC+ BC = soil plus green waste
compost and biochar combined). Note that the compost reference (GWCR) is not included here. Dashed line is the mean value, solid line is median, box is the upper and
lower quartile and whiskers are the 10th and 90th percentiles (n = 9)