COMPARISON OF DIFFERENT EXTRACTION METHODS FOR HEAVY METALS FROM “COMPOST” SUBSTRATES AND FROM TOMATO LEAVES AND FRUITS GROWN ON THESE SUBSTRATES

Tomatoes were grown on fermented domestic waste compost, pine needle substrate, mushroom substrate and mixtures of these substrates.

The concentration of heavy metals (Fe, Cu, Zn, Mn, Cd, Pb) in the different substrates were analysed by different extraction methods (A.L., NH₄OA_c, H₂SO₄/HCl), HNO₃, HNO₃/HCl). Leaves and fruits of the tomatoes grown on these substrates were analysed too, using HNO₃ and HNO₃/HClO₄ extraction.
Correlations were drawn between the heavy metals content in the substrates and tomato fruits and leaves.

Generally the most efficient extraction is obtained with HNO₃ 0.5 N. This method allows the best correlation between soil-, plant- and fruit contamination for the metals here considered.
Using the other soil extraction methods it is impossible to predict leaf and fruit contamination starting from soil analysis data.

Close correlations between metal contents in soil and fruit and leaves were also obtained for Zn by NH₄OA_c extraction and for Mn by A.L.

Nutrient Film Technique and Substrates, XXI IHC

J. COOSEMANS, P. Uyttebroeck

https://doi.org/10.17660/ActaHortic.1983.133.18