LIMITANTES QUÍMICOS PARA LA REVEGETACIÓN DE UNA ESCOMBRERA DE MINA ABANDONADA EN GALICIA

E. ALVAREZ, M.L. FERNANDEZ MARCOS, M.J. FERNÁNDEZ SANJURJO, C. VAAMONDE

Dpto. de Edafología y Química Agrícola, Escuela Politécnica Superior de Lugo, Campus Universitario, 27002 Lugo

 

Abstract. This study was carried out in the dump of an abandoned sulfide mine in Galicia (NW Spain), which contains chalcopyrite among other minerals. It aims to get information on the main chemical limiting factors to plant growth, paying particular attention to heavy metal contents and speciation. The dump samples were acid (pH in water ranging between 3.1 and 5.0), contained less than 0.5% organic carbon, less than 0.001% nitrogen, had an effective cation exchange capacity ranging between 0.75 and 4.97 cmol(+) kg-1, deficit of Ca, Mg and K, and more than 20% exchangeable aluminium in 85% of the samples. Iron, both total and available, is the most abundant heavy metal. The sequence of total and available heavy metal contents is: Fe > Cu > Mn > Zn > Cr. Copper is the dominant heavy metal in the exchangeable and soluble fractions, followed by Zn, Mn and Fe, Ni, Cr, Cd, Co and Pb were not detected.

Key words: mine dump, mine soil, chemical limiting factors, heavy metals.