Olive orchard amended with two experimental olive mill wastes mixtures: Effects on soil organic carbon, plant growth and yield

Amendments of olive orchard soil with two different preparations of olive mill solid waste (OMWMs) atthe rate of 9 ton ha1 per year for five years in two different plots were compared with an industry standardsoil amendment using urea. Both the OMWMs amendments showed significant increases in totalorganic carbon and humic substances in soil of approximately 40% and 58%, respectively, without negativeeffects on tree growth and yield. This work has shown that olive oil mill waste (OMW) can be recycledsafely using the bioremediation system used in this study. We suggest that this system is particularlybeneficial to organic farming and is an alternative solution to direct spreading of raw OMW on farm lands.