Use of olive mill waste mix as peat surrogate in substrate for strawberry soilless cultivation.

The aim of paper was to evaluate the suitability of olive mill waste mixture (OMWM) as growth media forstrawberry soilless cultivation. OMWM was used at the rate of 0, 25, 50, 75% (v/v) as peat substitute. Inorder to assess nutrient supply to plants by OMWM, the experimental design included fertigated (standard)and unfertigated sets. Some of the chemical and physical parameters of the growth media wereanalysed at the beginning and end of cultivation, while plant nutrient uptake was assessed by means ofpetiole- and leaf blade-tissue analyses for the main macro- (N, K, Ca, Mg, Na) and micro- (Fe, Mn, Zn, Cu)elements. Quantitative and qualitative assessments of yield were also made. Plants grown on OMWMamended substrate showed an initial slight phytotoxicity particularly at higher rate (75%) probably asa consequence of the high values of electrical conductivity recorded in the OMWM water extract.Successive water leaching caused by irrigation or fertigation reduced EC towards values compatible tostrawberry cultivation. Yield data and tissues analyses showed that OMWM performed adequately asa substitute for peat and satisfied the plant nutrient needs in the fertigated trial. However, it appeared thatnitrogen provided byOMWMwas insufficient in achieving adequate yield in the unfertigated trial. The useof OMWM showed high compatibility in soilless strawberry cultivation being an effective and cheapalternative to peat; therefore, a realistic cost reduction for growerswas evident. The relatively high amountof nutrients found in the growth media at the end of strawberry cultivation meant that it can be recycled inagriculture as soil amendment.