Fig. 8. Effect of historic biosolids applications on the phytoavailability of applied Cd salt to romaine lettuce; soils from long-term, biosolids-amended, and control soils from plots established in 1976 on Christina fine sandy loam (fine, kaolinitic, mesic Typic Paleudults). Soils with all treatments and Cd rates were adjusted to pH 6.5 in 0.01 M Ca(NO3)2 before growing ‘Paris Island’ romaine lettuce to maturity. The Cd concentration in heat-treated biosolids was 13.4 mg kg–1, and the Cd concentration in compost was 7.2 mg kg–1.