Fig. 5. Moisture effects on total copper concentration ([Cu]_tot) and "bioavailable" copper concentration ([Cu]_bio) in water extracts from soil systems incubated for 28 d. (A) [Cu]_tot from Cu-amended soil systems after incubation at different moisture conditions: dry (circles), variable (squares), 80% field capacity (triangles), 100% field capacity (crosses), and water-saturated soils (diamonds). The data presented are from duplicate soil systems and each point represents a single soil system. Fitted linear regression lines for each incubation condition are shown. (B) The [Cu]_bio to [Cu]_tot ratio in water extracts from Cu-amended soil systems after incubation at different moisture conditions: dry (circles), variable (squares), 80% field capacity (triangles), 100% field capacity (crosses), and soil slurry (diamonds) soils. The data presented are from duplicate soil systems and each point represents a single soil system. Three data points are missing due to loss of samples: dry, 800 µmol Cu kg^–1 soil; 100% field capacity, 200 µmol Cu kg^–1 soil; and variable, 800 µmol Cu kg^–1 soil.