Fig. 3. Available P with time in (a) topsoil (0–30 cm) and (b) subsoil (30–60 cm) following the application of 0, 10, 30, and 90 Mg ha-1 compost (fresh wt.). The sewage sludge compost was applied on 23 Mar. 1999.
Fig. 3. Available P with time in (a) topsoil (0–30 cm) and (b) subsoil (30–60 cm) following the application of 0, 10, 30, and 90 Mg ha-1 compost (fresh wt.). The sewage sludge compost was applied on 23 Mar. 1999.