Abstract

Impact of olive mill wastewaters used as fertilizer on soil quality and physiological behavior of coriander

Author(s): Razouk Rachid, Kajji Abdellah, Oubella Kaltoum

The impact of four amounts of olive mill wastewaters (OMW) ranged from 50 to 150m3/ha used as fertilizer on an alkaline soil qualitywas compared to water treatment based on measurement of soil pH, electrical conductivity and polyphenol content, using coriander as an indicator plant. The results revealed that soil pH and electrical conductivity changed slightly under all treatmentswith a maximal values under 150 m3/ha ofOMWwhich caused a decrease of soil pH by 0.3 points and increased soil electrical conductivity by 50 µS/cm during the first week of its application. However, soil polyphenols content increased widely under different treatments. Its initial value of 0.175 mg/g doubled under the treatment 100 m3/ha to reach three fold value under 150 m3/ha. The physiological parameters of the coriander improved under the treatments 50, 75 and 100 m3/ha and showed a certain stress under 150 m3/ha. Up to these results, OMWmay be used as fertilizer up to 100m3/ha without adversely affecting the alkaline soil quality in the arable layer. Beyond this amount, a particular attention should be paid, to soil polyphenols as far as their phytotoxicity is concerned, since a high concentration of polyphenols may exert an allelechemical effect.