3.3. Sequential chemical extractoil Cd fractionation results for BSES (Fig. 4-I) show that in the
control plots and those receiving chemical fertilizer or straw applications (NPK and SNPK) most of the Cd was present in the reducible
(40.5–48.9%) and residual (36.9–47.0%) fractions. In M1NPK and
M2NPK the residual fraction was no longer the dominant geochemical
phase. Bioavailable Cd (in the acid-exchangeable and reducibleion of soil Cd