A study of olive mill wastewaters obtained from different treatment processes effects on chemical and microbial properties of a Typic Xerofluvent soil and wheat yield

Abstract

This study was carried out to investigate the potential for the usability of treated olive mill wastewater OMW as an organic amendment in agricultural soils under Mediterranean climate conditions. OMW was treated by two different treatment processes as economical E-OMW and advanced A-OMW . The treated OMWs and raw OMW R-OMW were applied to a loamy soil at a rate of 100 m3 ha-1 year-1 for 2 years. Soils were sampled 15 days and about 5 months at harvest after OMW application for chemical and microbial analyses in each year. The total concentrations of N, P, Cu, Zn, and phenol of R-OMW decreased after both treatment processes while salinity EC and the total amounts of K, Na, and Ca increased. The applications of OMW caused changes in soil chemical pH, EC, Pext, Kext and microbial microbial biomass-C MB-C , microbial biomass-N MB-N , basal soil respiration BSR , N-mineralization N-min characteristics P