Olive mill wastewater effects on durum wheat crop attributes and soil microbial activities: A pilot study in Syria

Abstract

Olive mill wastewater is one of the environmental problems in semiarid regions. The main goals of this study were to investigate the impacts of different olive mill wastewater levels on durum wheat (Triticum aestivum var. Douma1) production and soil microbial activities (i.e., bacteria and fungi). A pot experiment was conducted during the growing seasons 2015/2017 to evaluate the effect of three levels of olive mill wastewater on both growth and productivity attributes of wheat. Vertisol soil samples were collected from southern Syria. Two months before wheat cultivation, three levels of olive mill wastewater: T5 (5 L/m 2), T10 (10 L/m2) and T15 (15 L/m 2) were added to pots filled with the collected soil samples. Also, a control (T0) free of olive mill wastewater was considered as a reference. Results showed a significant increase (p < 0.05) in germination rate (%), plant height (cm), ear length (cm), kernels number, kernels weight per ear (g) and grain yield (g/m2) compared to control. However, T5 treatment did not induce a significant increase in terms of ear length, kernels weight per ear or yield (in the second season). On the other hand, T10 treatment had recorded the best results compared with the other two treatments (T5, T15). Similarly, the results showed a significant increase in the number of bacterial and fungi cells by increasing olive mill wastewater concentration. This research provides promising results toward using olive mill wastewater in an eco-friendly way under Syrian conditions.

Study of the Phytotoxicity of Olive Mill Wastewater on Germination and Vegetative Growth – Case of Tomato (S<i>olanum lycopersicum</i> L).

“…On the other hand, our results show a significant effect of OMW on the vegetative growth of tomato plants. These results are comparable to those found by Khalil and al. (2021), where OMW positively affects, at doses of T5 (5 L/m 2 ) and T10 (10 L/m 2 ), the height of wheat plants.…”

“…(2021), where OMW positively affects, at doses of T5 (5 L/m 2 ) and T10 (10 L/m 2 ), the height of wheat plants. This could be attributed to the organic and nutritional loading of OMW, as well as the reduction in levels of phenols and other phytotoxic compounds as a result of the different dilutions [Fausto Cereti and al., 2004;Khalil and al., 2021;Rusan and Malkawi, 2016;Sidari and al., 2010]. This positive vegetative growth is attributed to the high amounts of protein, polysaccharides, humic acids, and macro and micro mineral elements present in these effluents [Faraloni and al., 2023;Sawalha and al., 2014].…”

The Effect of Varying Olive Mill Wastewater Concentrations on Soil Free-Living Nematode Communities and Lettuce Growth

“…The land application of olive mill wastewater has been reported to increase organic matter content and enrich essential inorganic nutrients (P, K, Mg, Fe), vital for promoting plant growth [13]. Numerous studies reported that OMW contributed to positive metabolic and physiological responses in plants, enhancing their growth [4,10,14]. However, interest has arisen regarding its impact not only on subsequent effects on crop productivity but also on soil organisms.…”

Agronomic Impact and Phytotoxicity of Olive Mill Wastewater as a Biofertilizer on <i>Vicia faba</i> L.

“…In this context, Caruso et al (2018) as well as Chatzistathis and Koutsos (2017) published two valuable studies on the impacts of OMW spreading on soil and crops, their findings revealed that utilizing OMW induced beneficial effects on soil. Moreover, these effluents have been reported to exert adverse effects on plant growth, leading to delays in germination and impeded plant development, primarily attributed to elevated concentrations of phenolic compounds or heavy metals, particularly in non-diluted solutions (Khalil et al, 2021). Despite these documented negative implications, it is crucial to acknowledge that these effluents contain significant nutrient content.…”