(MDPI, 2015-09-18) Kurtz, Markus Peter; Peikert, Benjamin; Brühl, Carsten; Dag, Arnon; Zipori, Isaac; Hasan, Jawad; Schaumann, Gabriele Ellen
Although olive mill wastewater (OMW) is often applied onto soil and is known
to be phytotoxic, its impact on soil fauna is still unknown. The objective of this study was
to investigate how OMW spreading in olive orchards affects Oribatida and Collembola
communities, physicochemical soil properties and their interdependency. For this, we
treated plots in two study sites (Gilat, Bait Reema) with OMW. Among others, the sites
differed in irrigation practice, soil type and climate. We observed that soil acidity and
water repellency developed to a lower extent in Gilat than in Bait Reema. This may be
explained by irrigation-induced dilution and leaching of OMW compounds in Gilat. In Bait
Reema, OMW application suppressed emergence of Oribatida and induced a community
shift, but the abundance of Collembola increased in OMW and water-treated plots. In
Gilat, Oribatida abundance increased after OMW application. The effects of OMW
application on soil biota result from an interaction between stimulation of biological activity and suppression of sensitive species by toxic compounds. Environmental and
management conditions are relevant for the degree and persistence of the effects.
Moreover, this study underlines the need for detailed research on the ecotoxicological
effects of OMW at different application rates.