In our
experiment, the effectiveness of GMF was tested on “Tarocco” orange trees of twenty years, severely
suffering from Fe chlorosis, also by mixing GMF with meat meal (MM) or digested vine vinasse (DVV),
thus comparing these treatments to the conventional Fe-chelate fertilization and the Fe-unfertilized
control.
The GMF + DVV mixture showed to be able to supply adequately micronutrients (particularly Fe) on long
term, reducing the chlorosis symptoms, increasing the leaf SPAD index, Fe concentration and decreasing
Fe index. No significant effect on yield and fruit quality was noticed. Our results indicated that these
innovative formulates, and in particular glass-matrix based fertilizer mixed with digested vine vinasse,
could be used as an “environmental friendly” fertilizer, allowing not only to reduce the use of chemicals
(such as Fe-chelate), but also to re-use industrial wastes and organic residues which gave an “adding
value” to these novel organo-mineral formulates.