A study was done using residues from olive oil processing industries i
n order to determine positive or negative effects if they would be use
d as fertilizers in soil. Main elements involved in plant nutrition as
well as some soils characteristics were determined. Liquid and solid
residue from olives increased the organic matter content of soils and
the availability of some nutrients like N, K, Fe, Mn and Zn. However t
he input of these residues favored an increment of electrical conducti
vity of this calcareous soil.