The behavior of metals in biosolids-amended soils over time is important to the understanding of metal chemistry, and for legislation. Changes extractability and uptake by crops of biosolids metals in a field experiment, started in 1942, were measured to assess whether Zn and Cd are either fixed by the biosolids/soil or are released as the biosolids organic matter decomposes. Extractability of Zn in 0.1 M CaCl₂ as a proportion of total ranged from 0.5 to 3% and that of Cd from 4 to 18%, and were higher in biosolids-amended than farmyard manure or fertilizer-amended soils. The relationships between total soil and crop metal concentrations were linear, with no evidence of a plateau across the range of soil metal concentrations. The slopes of the soil-plant relationships were generally in the order red beet >sugar beet >carrot >barley. It is concluded that up to 23 years after biosolids applications cease at this site in which soil pH was maintained close to 6.5, Zn and Cd extractability and bioavailability neither decreased nor increased consistently. Paired soil and winter wheat samples were collected from two long-term biosolids experiments and a national survey of fields that did not regularly receive biosolids. Soil pH and total soil cadmium together resulted in a highly significant model (P<0.001) that explained 50% of the variation in grain concentrations with log grain cadmium (mg/kg) = 0.28 + 0.44 log soil cadmium (mg/kg) – 0.18 soil pH. Similar relationships were found for both biosolids and non-biosolids-treated soils. This empirical model can be used, for example, to test whether the proposed new EU limits for Cd concentrations in soils where biosolids are applied are likely to generate grain which exceeds the 2001 EU Food Regulation. It also demonstrates that management of pH is an important factor for soils that contain elevated Cd concentrations.