Long-term application of olive-mill wastewater affects soil chemical and microbial properties (original) (raw)
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Response of Soil Properties and Microbial Communities to the Application of Olive Mill Wastewaters
A laboratory trial was carried out to evaluate the short-term influence of different concentrations of olive mill wastewaters (OMW) on soil physico-chemical properties and microbial community. After 30 days' incubation, no significant changes occurred in soil pH values and humified organic carbon; soil organic carbon and total water-soluble phenols (WSP) significantly increased. Addition of OMW to the soil caused modification in microbial counts and microbial community structure. Bacteria decreased significantly up to 86% for 100% OMW treatment. No significant differences were found for fungal community in the soil treated up to 50% OMW while a decrease in 50% was found when 100% OMW was applied. The fungal: bacteria ratio increased significantly. The actinomycetes CFU (colony forming units) decreased gradually up to a maximum of 38% when OMW dose increased. Our results evidenced that the storage of OMW in open-air lagoons for a 4-month period before its soil application and the appropriate dilution with irrigation water without any further treatment can be an inexpensive technology to be adopted by small-sized olive mills.
Asian Soil Research Journal
Aims: In Tunisia, Climatic changes and water shortage has led to the reuse of treated municipal wastewater (TMWW) in the agricultural sector since the sixties. This work was intended to study the short, medium, and long-term impacts of this practice on soil microbial properties. Study Design: Five different experimental fields were chosen which had been irrigated with TMWW for 10, 20, 25, and 28 years, respectively. A pluvial irrigated field was selected as a control. Place and Duration of Study: The study was conducted in Zaouit Sousse (Tunisian Sahel region) located in the south of Sousse City (longitude: 35°47′, latitude: 10°38′ and of altitudes: 20 m N.G.T.). The soil sampling campaign was carried out at the end of the dry season (September 2014). This study was undertaken in a semi-arid area that is facing a water crisis (water shortage and irreversible seawater intrusion). Methodology: Soil fecal pollution indicators were determined with the most probable number MPN method. Ba...
Effects of olive mill wastewater disposal on soil: Interaction mechanisms during different seasons
Journal of Hydrology and Hydromechanics, 2016
Environmental conditions play a major role for effects of olive mill wastewater (OMW) application to soil. Choosing a different season for OMW application than the commonly practiced winter, may help avoid negative effects. However, understanding of the OMW-soil interaction during different seasons is still incomplete due to the lack of comparative data. In this study, an 18 months field experiment was carried out in an olive orchard in West Bank. Degree and persistence of soil salinization, acidification, accumulation of phenolic compounds and soil water repellency were investigated as a function of soil depth and time elapsed after OMW application, which was performed either in spring, summer (with and without irrigation) or winter. The persistence of negative effects increased with duration of the hot and dry period following the application due to accumulation and polymerization of OMW. On the other hand, leaching of OMW components to groundwater is favored during the rainy seas...
Microbiological Research, 2006
We investigated the effect of untreated and biologically treated olive mill wastewater (OMW) spreading on the soil characteristics and the microbial communities. The water holding capacity, the salinity and the content of total organic carbon, humus, total nitrogen, phosphate and potassium increased when the spread amounts of the treated or untreated OMW increased. The OMW treated soil exhibited significantly higher respiration compared to the control soil. However, the C-CO 2 /C tot ratio decreased from 1.7 in the control soil to 0.5 in the soil amended with 100 m 3 ha À1 of untreated OMW. However, it slightly decreased to 1.15 in the soil amended with 400 m 3 ha À1 of treated OMW. The treated OMW increased the total mesophylic number while the number of fungi and nitrifiers decreased. Actinomycetes and spore-forming bacteria were neither sensitive to treated nor to untreated OMW. The total coliforms increased with higher doses of treated and untreated OMW. A toxic effect of the untreated OMW appeared from 100 m 3 ha À1 . This toxicity was more significant with 200 m 3 ha À1 , where microflora of total mesophilic, yeasts and moulds, actinomycetes, and nitrifiers were seriously inhibited except for total coliforms and spore-forming bacteria.
Agronomy
The long-term effects of the olive mill wastewater (OMWW) spreading on soil chemical properties, microbial community, and olive tree parameters have been far poorly investigated. Therefore, this study aims to evaluate the effect of OMWW application on an olive orchard, and samples were collected at two different depths (0–20 cm and 20–40 cm) and 14 days, one year and two years from the end of the OMWW spreading on soil chemical characteristics and soil microbial structures. Variations of soil chemical parameters (pH, salinity, available P, and water-extractable organic C) were observed particularly at 14 days after spreading at both depths. All these parameters reached similar values to the soil after two years, except for available phosphorus. Firmicutes, Proteobacteria, and Actinobacteria are the most abundant phyla: only Firmicutes were negatively affected by the OMWW spreading after 14 days, suggesting that Gram-positive bacteria were probably negatively influenced by the additi...
Agriculture, Ecosystems & Environment, 2010
ABSTRACT The application of fresh olive mill wastewater (OMW) to the soil surface of an olive (Olea europaea, L.) orchard was studied as a low cost alternative method for the disposal of this waste. OMW were applied to a Cretan orchard with 20-year-old trees (cv. ‘Kalamata’) during winter time for 3 consecutive years, at a maximum annual rate of 420 m3 ha−1. The effects on soil properties and composition (pH, EC, N, P, K, organic matter and phenolic content), yield, photosynthesis and nutritional status of the trees were studied. In a separate experiment, the possibility for groundwater pollution was studied in large lysimeters (60 m3 of soil volume). The most important effects on soil composition included a significant increase on availability of K, which enhanced soil fertility, and an increase of phenolic compounds in the OMW-treated soil. However, phenols decomposed rapidly and no accumulation trend was observed after subsequent applications. No other negative effects on soil properties and plant behavior were observed throughout the experimental period, while the composition of drainage water at a soil depth of 2 m was not altered by the application of OMW. Based on the dosage used, the cost for adopting the method was estimated to less than €0.007 kg−1 of processed olive fruit.
Diversity of soil fungi exposed to fresh and stored Olive Mill Wastewater
2010
Olive Mill Wastewater (OMW) management is one of the most challenging environmental problems in Mediterranean countries. Its recycling in soil is an alternative of valorization mean of interest. The effect of OMW on growth of soil fungi, a principal element of biodegradability in soil, was investigated in this study. In a field trial, OMW application to soil at 8 l/m2 and 16 l/m2 caused an increase in abundances of soil fungi during the 6 months following the spreading. In a microcosm essay, growth of soil fungi was better in fresh OMW than in stored OMW becoming after storage more antimicrobial and phytotoxic. In fresh OMW sterilized then inoculated by soil microflora, survivors of soil fungi were constituted mainly by yeasts which showed an increase of abundances from 5.09 10 4 CFU/ml to 5.02 10 8 CFU/ml after 15 days of incubation at 20°C. In stored sterilized then inoculated OMW, yeasts showed a fast reduction then a survival at low levels. Soil moulds were a sensitize group to ...
Chemosphere, 2007
This study was carried out to evaluate the effect of olive mill wastewater (OMW) land-spreading on soil chemical properties and microbial activity. The experiment was conducted over four consecutive years (2012-2015) on olive cultivar 'Nabali Muhassan' grown in a private orchard located in Ramtha district, Irbid governorate. OMW was applied each year to an orchard of 16-year-old trees in December at five application rates: a control (no application of OMW) and 5, 10, 15 and 20 L m-2. Results of OMW analysis showed normal properties of OMW used in Jordan. Results of the soil analysis showed significant differences between the application treatments and the control for most of the measured parameters. Application of OMW at 15 and 20 L m-2 significantly raised soil electrical conductivity (EC), Na, SO4, P, K, Fe, Cu, Mn, Zn, total phenols, organic matter and dissolved organic carbon compared with the control. Soil microbiological tests indicated promotion of microbial activity in response to OMW application compared with the control.
Applied Soil Ecology, 2007
Olive mill wastewater (OMW) constitutes a major environmental problem for Mediterranean countries, where most of the world olive oil production takes place. The recycling of the OMW and its use as water for irrigation in agriculture, provided that its impact on soil and plant is established, is an attractive possibility for the Mediterranean countries. Investigations were performed on the influence of agronomic application of OMW (amount applied: 30, 60, 100 and 150 m 3 ha À1 ) in a field of olive trees on trees characters (photosynthesis, root-soluble carbohydrate and root colonisation), soil properties, and soil microbial community structure. Specific attention was paid to arbuscular mycorrhizal (AM) fungi. The soil fatty acid methyl ester (FAME) 16:1o5 was used to quantify biomass of AM fungi and the root FAME 16:1o5 analysis was used as index for the development of colonisation in the olive trees roots. A significant increase in organic C, C/N ratio, extractable phosphorus and exchangeable potassium was found after one year of agronomic application of OMW. The development of saprophytic fungi was significantly higher in the OMW amended soils, whereas the abundance of the soil FAME 16:1o5, root FAME 16:1o5, photosynthetic rates and the amount of the total root-soluble carbohydrate were decreased significantly after agronomic application of OMW. A principal component analysis (PCA) of the trees characteristics profiles showed discrimination between the nonirrigated and the OMW irrigated olive trees. These findings suggest that the altering functioning of arbuscular mycorrhizas should be considered as potential factors mediating olive trees responses to agronomic application of OMW when the OMW dose applied is higher than 30 m 3 ha À1 . To our knowledge, this is the first report of alterations in the soil FAME 16:1o5 and root FAME 16:1o5 due to land spreading of OMW. r