Abstract: Spraying OMW on poor sandy soils in the olive orchards induces increasing of the organic matter content, the formation of aggregates and improving the soil structure stability. Hence, OMW can be an alternative and effective way to control this polluting sewage. Since 1995 a field experiment is running in an olive plot in chammakh-Zarzis, south Tunisia, where rates of 50, 100 and 200 m 3 of OMW were sprayed yearly on 1 ha fields with 16 olives trees per ha. Data collected in 2006 showed an increase in organic matter content from originally 0.06 to 1.27 %, an increase in the amount of aggregates > 2 mm to 34%, and an increase in the threshold friction velocity for deflation to 12 m sec -1 for the 200 m 3 ha -1 application
