Zn ions were adsorbed from aq. solns. on peat, compost, pine bark, spent mushroom substrate, Fucus sp., bailie seaweeds and a residue from their supercrit. CO2 extn. In the next step the adsorbents were extd. with distd. water, NH4 citrate and KNO3 solns. to recover soluble, bioavailable and mobile fractions of Zn ions and other nutrients. The bioavailable fraction constituted 73.5-93.9%, water-sol. fraction 2.92-19.9% while the mobile fraction 33.6-57.2% of adsorbed Zn ions depending on the biomass type.