Short-term Effects of Applying Olive Mill Waste on Turfgrass
K. DRAGOIDOU1, Α. E. NIKOLOPOULOU2, M. .Ο..ORA3, P. VYRLAS3
1Institute of Industrial & Forage Plants,
Hellenic Agricultural Organization DEMETER,
1, Theofrastos str., Larissa 41335,
GREECE
2Department of Crop Science, Agricultural
University of Athens,
75 Iera Odos, Athens 11855,
GREECE
3Department of Agrotechnology,
University of Thessaly,
Gaiopolis, Larissa 41500,
ORCID ID: 0000-0002-3617-9976
GREECE
Abstract: The reuse of wastes in agriculture and landscape is often viewed as one way to conserve existing
resources. Among the organic waste materials produced by agricultural activities, olive mill wastes derived
from the olive oil extraction process may represent a suitable soil amendment. This study evaluated the effect
of olive mill wastewater (OMW) application on turfgrass growth and quality and on soil electrical conductivity
and pH. Olive mill wastewater at different doses (0, 3.0, and 6.0 L/m2) was applied on a sodded turfgrass grown
in clay loamy soil, identically irrigated with fresh water, and without any chemical fertilizer application. The
results revealed that OMW application had a positive effect on the tested turfgrass, improving visual quality
and increasing the dry weight of the clipping yield, in proportion to doses applied. An increase in electrical
conductivity was observed in wastewater-irrigated soil while OMW did not remarkably change the initial soil
pH.
Key-Words: Olive wastes, fertigation, visual quality, clipping yield, salinity.
Received: November 23, 2022. Revised: March 29, 2023. Accepted: April 23, 2023. Published: May 12, 2023.
1 Introduction
Olive oil production represents a traditional branch
of Greek agriculture. The olive oil extraction
process, however, involves the generation of large
amounts of olive mill wastewater (OMW), a by-
product that constitutes a serious environmental
problem, due to its high polluting load.
OMW is a mixture of vegetation water, water
used in the various stages of the oil extraction
process, and soft tissues of the olive fruit. It's
characterized by intensive violet-dark brown up to
black color, strong offensive smell, pH between 3
and 6, high electrical conductivity, high degree of
organic pollution, high content of polyphenols, and
high content of solid matter, [1], [2], [3].
Those wastes may be reused through the soil,
directly (wastewaters), or following a composting
process, [4], [5]. However, the direct application to
agricultural soils as organic fertilizers is the most
frequently used method nowadays, [2], [6].
This by-product is normally rich in Potassium
and, to a lesser extent, in other nutrients (Nitrogen,
Phosphorous, Calcium, and Magnesium). Therefore,
they can replace the nutritional elements provided
through fertilization. However, the spreading of
OMW on soil could pose some disadvantages to soil
properties because of the characteristics of the
wastes.
OMW application effects on several agricultural
crops have been well documented, [2], [3], [7] but
little is known, however, about the impact of OMW
on turfgrass and landscape crops.
The use of these wastewaters on soils may
enhance their fertility, considering the fertilizing
WSEAS TRANSACTIONS on ENVIRONMENT and DEVELOPMENT
DOI: 10.37394/232015.2023.19.42
K. Dragoidou, Α. E. Nikolopoulou,
M. Kοkkora, P. Vyrlas
E-ISSN: 2224-3496
449
Volume 19, 2023
properties of the waste, such as organic matter, P, K,
and N. It does not contain heavy metals or
pathogenic microorganisms. Nevertheless, the use
of this waste may lead to some disadvantages,
related to acidity, salinity, lipids, organic acids, and
phenolic compounds accumulation, [4].
Making the hypothesis that the high contents of
nutrient levels in OMW may improve the soil’s
fertility, this study aims to evaluate the effects of
olive mill waste application on the growth and
quality of a sodded turfgrass. Also, the assessment
of the effects on some soil properties, focusing on
electrical conductivity and pH, parameters of direct
interest to turf culture.
2 Materials and Methods
A field experiment was carried out on clay loam soil
(41% sand, 20% silt, 39% clay) at the research field
of the University of Thessaly, Gaiopolis campus,
Larissa, Greece.
Twelve 1.60 × 1.60 m plots were prepared
during the early spring of 2020 and sodded with a
mixture of tall fescue (Festuca arundinacea
Schreb), perennial ryegrass (Lolium perenne L.) and
Kentucky bluegrass (Poa pratensis L.).
The sod, selected for this study is the most
frequently used mixture in sports fields and parks in
Greece, and it represents their largest area. The
experimental design included three replications of
three treatments, including the application of 6.0
L/m2 of OMW (OW6.0), the application of 3.0 L/m2
of OMW (OW3.0), and a control treatment (C) with
no OMW application.
Sod was placed on the soil surface and allowed
to establish for a period of 20 days, a period typical
for establishing turfgrass outdoors. During the
establishment period, no OMW was applied. The
turf was sprinkler-irrigated (freshwater) at a 2-day
frequency during the establishment period and then
water was applied every 3 or 4 days based on
cumulative evapotranspiration replenishment unless
rainfall of at least 6 mm was measured. OMW was
applied through the irrigation system in four-fold
replication.
The main turfgrass characteristics considered in
the study were color and shoot growth. The color is
one of the best indicators of the aspect quality of
turfgrass and was monitored throughout the study.
Shoot growth, measured as shoot biomass
production, was used to assess the status of the turf.
Clippings from each plot were collected monthly at
a height of 6 cm with a walk-behind rotary mower
from an area of 1 m2. The shoot biomass samples
were oven dried at 65°C for 48 h and weighed. The
shoot dry weight was calculated as the clipping dry
weight per square meter.
Soil salinity and pH data were obtained by soil
coring from the topsoil (0 - 30 cm). Soil samples
were collected at three points in each plot. The
samples were then blended, and one sample was
analyzed. Soil electrical conductivity sampling was
carried out five times over 7 months. Soil pH was
measured three times, before OMW application, at
the middle and the end of the experiment.
All the results were subjected to analysis of
variance. A probability level of α=0.05 was chosen
to establish the statistical significance among treated
and control samples.
3 Results and Discussion
3.1 Characteristics of Olive Mill Wastewater
Olive mill wastewater (OMW) was collected during
harvest season (December 2019) from a nearby
olive mill and was stored in a plastic container.
Selected parameters of OMW applied on turfgrass
cultivated soil are given in Table 1. The analysis has
shown that OMW is a moderately acidic liquid
waste (pH = 5.8) with high electrical conductivity
(EC = 8.92 mS/cm). The applied OMW has been
rich in phosphorus and potassium while the content
in total nitrogen has been low.
Table 1. Olive mill waste quality parameters
Parameter
Value
Electrical Conductivity (mS/cm)
8.92
pH
5.8
Solid residue (%)
6.2
Available P (mg L-1)
1103
Available K (mg L-1)
980
Mineral N [NH4-N + NO3-N] (mg L-1)
75
The OMW characteristics depend on various factors
like the olive variety, the climatic conditions, the
type of extraction process, the use of pesticides and
fertilizers, and the ripening of olives, [1], [7], [8].
3.2 Turf Response to OMW Application
3.2.1 Visual Evaluation
Turf color is a key component of aesthetic quality
and a good indicator of water and nutrient status.
Therefore, color is often evaluated in turfgrass
experiments. Color is traditionally evaluated by
visually rating turf plots on a scale of 1 to 9, with 1
representing the lowest quality and 9 representing
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K. Dragoidou, Α. E. Nikolopoulou,
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the highest quality turf. A rating of 6 is considered
minimally acceptable, [9], [10].
Visual rating requires minimum labor and
provides quick quality estimation. To avoid any
differences in assessments that may occur due to the
subjectivities of the raters, all visual assessments are
carried out by the same individual, [11], [12].
Fig. 1 presents the turf color evaluation for each
treatment. The value of each treatment is the
average value of its 3 repetitive plots (which is why
decimal numbers are displayed). The image is a set
of diagrams made in Excel with automatic color
formatting of squares, depending on their numerical
value.
Fig. 1: Grading of turf appearance in terms of color,
at each evaluation date and for each treatment
In the early stages of the experiment (April - May)
there is a color balance between treatments, which
begins to vary from June onwards. It is observed
that control (C) consistently shows the lowest score
until the end of the experiment. OMW application
treatments show better scores than the control,
systematically from May onwards, reaching grade
7.7 (OW3.0 treatment) and grade 8 (OW6.0
treatment) in the last month of the experiment.
3.2.2 Turfgrass Growth
The growth rate of the turfgrass was measured at
regular intervals, with a cut at a height of 6 cm. A
total of 6 cuts were made during the period from
May to October 2020.
Table 2 gives the measured dry biomass for each
treatment. After the first cut where there was a
balance without statistically significant differences,
the OMW treatments, are superior to the control, in
all subsequent cut-collections, presenting even
statistically significant differences from the third cut
onwards.
OMW application influenced dry weight
production, which was higher than the control,
mainly in the last part of the experimental period.
The treatment of OW application with the dose
of 3.0 L/m2 (ΟW3.0), is superior to the control from
the 3rd cut onwards, however showing statistically
significant differences only in the last cut. The
OW6.0 treatment prevailed with statistically
significant differences from the control in the last
two cuts.
The overall (average) yield picture is presented
in the diagram of Fig. 2 as the calculated dry
biomass production daily for each treatment. OW
treatments were superior to that of the control,
without differing statistically significantly. The 6.0
L/m2 (OW6.0) application treatment yielded 1.43 g
of dry biomass per m2 per day, while the 3.0 L/m2
(OW3.0) application treatment yielded 1.38
g/m2/day. The OW6.0 yielded a total of 15.9% more
than the control, while the OW3.0 was slightly
behind the previous one, yielding 12.0% more than
the control.
The potential use of OMW on cultivated crops
was examined in a review. The results reported in
the literature are not consistent. The application of
OMW appears to modify soil/plant relationships,
[2].
The effects of untreated and treated olive mill
wastewater on seed germination, plant growth, and
soil fertility were studied. Tomato, chickpea, bean,
wheat, and barley were tested for the germination
index and growth in soil irrigated by olive mill
wastewater The treated plants showed an
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improvement in seed biomass, spike number, plant
growth, and a similar or even better dry productivity
than plants irrigated with water, [6].
Table 2. Clippings’ dry weight as affected by OMW application
Cutting
DaP
Treatment
C
OW 3.0
OW 6.0
Dry weight (g)
1st
40
23.1
(1.6)
24.8
(1.6)
22.2
(1.5)
2nd
70
48.2
(4.3)
48.7
(4.5)
46.1
(4.9)
3rd
102
30.8
(2.7)
35.7
(4.7)
35.9
(5.1)
4th
137
39.9
(3.7)
43.2
(1.7)
45.3
(5.5)
5th
175
48.0
(3.2)
58.2
(2.6)
64.6
(3.3)
6th
206
38.0
(3.3)
46.1
(4.3)
55.1
(5.2)
DaP: Days after planting; Numbers in parenthesis represent the Standard Deviation
Fig. 2: Turfgrass growing rate over time as affected by OMW application
In the irrigation of maize planted in a pot
experiment, the results indicated that untreated
OMW reduced plant growth, while the treated
OMW improved plant growth, [13].
In turfgrass culture, olive waste has been tested
in a few studies either in treated or untreated form.
The OMW application as an organic fertilizer gave
increased rye-grass growth parameters (fresh and
dry weight, and LAI) in comparison with
unfertilized treatment, [14].
In a short paper, focused on nutrient absorption
by ryegrass, which was grown with a variety of
compost and fertilizer treatments conducted in pot
culture, the researchers concluded that olive mill
compost increased ryegrass fresh weight, [15].
In a 2-year field, study evaluated composted
olive mill waste as a soil amendment in
bermudagrass, the application resulted in a minor
reduction in plant visual quality during the cold
periods but in a slight improvement during the warm
periods. The clipping dry weights were increased by
composted olive mill waste amendments in the first
year but were unaffected in the second year, [5].
A field study examined the effects of olive mill
compost soil amendment (OMC) on turfgrass
establishment and growth. OMC amendment
improved the visual quality of tall fescue during
establishment and increased the dry weight of the
clipping yield. The visual quality and clipping yield
of bermudagrass did not exhibit any significant
differences among the treatments, [16].
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3.4 Soil Analysis
Based on the control treatment EC, an increase in
such parameters was observed as a function of
OMW application and time (Fig. 3). Although the
electrical conductivity values during the experiment
have no significant changes, the OMW treatments
reached their highest levels at the end of the
experiment, but within the permissible limits, that is
less than 600 µS/cm (0.6 mS/cm). A significant
difference in soil electrical conductivity in relation
to control has been observed only in the OW6.0
treatment. This elevation can be explained mainly
by the high salinity of the OMW and the richness of
mineral elements. Such results were consistent with
previous studies, [2], [3], [17], [18]. The EC
declination in all treatments is probably because of
increased rainfall events during the mid-period of
the study that leached the salts.
In [19], the author lists the parameters a turfgrass
manager should consider in evaluating irrigation
water quality. As indicated, waters with EC values
greater than 0.7 mS/cm present increased salinity
problems, and suggest avoiding using any water
with an EC above 3 mS/cm. Water with an EC of
1.5 mS/cm may be suitable for grass grown on
sandy soil with good drainage, but the same water
may prove injurious within a very short period if
used to irrigate the same grass grown on clay soil.
Fig. 3: Soil electrical conductivity (EC) evolution as a function of applied OMW and time. Asterisks indicate
significant differences (P < 0.05) among data
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In [19], the author also gives a general guide to the
salt tolerance of individual turf grasses. Soils with
EC values below 3 mS/cm are considered
satisfactory for most turfgrasses. EC values between
3 and 10 mS/cm indicate soils in which only a few
salt-tolerant turfgrass species can survive. As
indicated, Kentucky bluegrass will tolerate a soil
salinity of up to 3 mS/cm, while tall fescue and
perennial ryegrass are moderately tolerant (6 to 10
mS/cm).
Other researchers, [20], reviewing the salinity
tolerance of turfgrasses characterize tall fescue as
moderate tolerant (6–10 mS/cm) while Kentucky
bluegrass as moderate sensitive (3–6 mS/cm) and
perennial ryegrass as sensitive (<3 mS/cm).
In general, most tall fescue cultivars are
considered to have good tolerance to salts. Kentucky
bluegrass and perennial ryegrasses offer moderate
resistance to salts in the soil.
In [3], the authors refer to differences among
researchers with regard to electrical conductivity,
that ascribed to the differences in the kind of OMW
used (treated or untreated, i.e., raw), as well as to
the dose of application(s), repetition (disposal for
many years or not) and soil type (the content of
clay, carbonates, and organic matter).
A significant increase in soil electrical
conductivity has been observed with the increase of
the doses applied (25, 50, 75, and 100 m³ /ha), [21].
Similarly, olive mill waste application increased
soil electrical conductivity, and this increase was
proportional to the added OMW quantity, [7], [22].
The rise of the soil EC with increasing OMW
rates and the highest OMW dose applied almost
duplicates the soil salinity, [4]. A gradual rise of
soil EC following the application of increasing
quantities of treated OMW on maize-cropped soil
has been recorded also, [23].
The electrical conductivity of sandy soil
increased proportionally to the increase in the OMW
quantity and decreased with depth in all analysed
soils, [24].
Despite the OMW's moderate acidic pH (5.8),
the application does not have a significant effect on
the soil's initial values, although a slight decrease in
pH has been observed for the two OMW fertigated
soils. Levels of pH at C treatment ranged between
7.32 and 7.38 at the begging and at the end of the
experiment respectively. For OW3.0, pH values
ranged from 7.37 to 7.31 and these for OW6.0
treatment ranged between 7.35 and 7.33 (Fig. 4).
Thus, the pH values recorded for the different
treatments after 222 days have been always slightly
alkaline (< 7.5).
In [25], the authors reported that after 3 years of
application, there were no significant differences in
EC, between control and OMW-treated plots, and
no effects were observed in the respective soil
properties, indicating that the buffering capacity of
the soil could counterbalance these negative effects.
The addition of treated or untreated OMW did
not show any effect on the initial soil pH, [22].
Similar results have been published even with high
acidity OMW (pH=4.46), [21].
In this context, [25], have recorded no difference
in pH after three years of OMW application.
Moreover, [24], have noticed no significant
difference in the soil pH in response to the
application of increasing OMW doses. Three OMW
levels (50, 100, and 200 m3/ha/year were applied
over eight successive years. Despite the acidic pH of
OMW, a slight increase in pH values was observed
for the soil amended with a dose of 100 and 200
m3/ha. The pH increase did not exceed 0.5 units for
the soil treated with 200 m3/ha in relation to the
control soil. the pH of the soil amended with 50
m3/ha was not statistically different from the control
soil, [24].
Soil plots amended with alkaline OMW show a
considerable increase of the pH, proportional to the
rate of application but the pH of the treated soils did
recover to the control values in about two months,
[4].
In pot-planted maize untreated OMW application
increased soil salinity, while treated OMW resulted
in lower soil pH, [13]. This can be explained by the
buffering capacity of the soil, neutralizing the
acidity of the OMW, [21], [24], [26].
Fig. 4: Soil pH in control (C) and OMW-treated
turfgrass. Data points represent the mean from 3
plots ±standard deviation
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4 Conclusion
The main objective of this study was to evaluate the
effects of olive mill waste application on growth and
quality of a sodded turfgrass.
The results showed that the application of OMW
had a positive effect on the growth and quality of
turfgrass which is strongly related to the enrichment
of the soil with nutrients. The dose of 6.0 L/m2 was
the most favorable for the development as well as
for the quality of the tested grass.
The results also showed that the application of
OMW on clay loam soil led to an increase of the
soil's initial EC, yet not significantly, in proportion
to the doses applied. Although its moderate acidity,
the application of OMW did not remarkably change
the initial pH of the soil.
Despite the promising data collected, longer
experiments under different soil conditions are still
required to define the long-term effects of OMW
application on both plant response and soil
properties.
Olive mill waste application seems to be a
solution for the management of turfgrass because it
could limit the use of chemical fertilizers. However,
this practice should take into account the cumulative
effect of soil salinization, which would with time
transform the soil into an unproductive one.
References:
[1] Tsagaraki, E., H.N. Lazarides, K.B. Petrotos,
Olive Mill Wastewater Treatment. In:
Oreopoulou, V., Russ, W. (eds) Utilization of
By-Products and Treatment of Waste in the
Food Industry, Springer, Boston, MA, 2007.
[2] Barbera, A.C., C. Maucieri, V. Cavallaro, A.
Ioppolo, G. Spagna, Effects of Spreading
Olive Mill Wastewater on Soil Properties and
Crops, A Review, Agricultural Water
Management, 119, 2013, pp. 43-53.
[3] Chatzistathis, T., and T. Koutsos, Olive Mill
Wastewater as a Source of Organic Matter,
Water and Nutrients for Restoration of
Degraded Soils and for Crops Managed with
Sustainable Systems, Agricultural Water
Management, 190, 2017, pp. 55-64.
[4] Sierra, J., E. Martí, M. Antonia Garau, R.
Cruañas, Effects of the Agronomic Use of
Olive Oil Mill Wastewater: Field Experiment,
Science of the Total Environment, 378, 2007,
pp. 90-94.
[5] Ntoulas, N., P.A. Nektarios, G. Gogoula,
Evaluation of Olive Mill Waste Compost as a
Soil Amendment for Cynodon dactylon Turf
Establishment, Growth, and Anchorage,
HortScience, 46(6), 2011, pp. 937–945.
[6] Mekki, A., A. Dhouib, F. Aloui, S. Sayadi.
Olive Wastewater as an Ecological Fertiliser.
Agron. Sustain. Dev., 26, 2006, pp.61-67.
[7] Mekki, A., A. Dhouib, F. Feki, S. Sayadi,
Review: Effects of Olive Mill Wastewater
Application on Soil Properties and Plants
Growth, Int. J. Recycl. Org. Waste Agric, 2,
2013, 15.
[8] Mechri, B., H. Cheheb, O. Boussadia, F.
Attia, F. Ben Mariem, M. Braham, M.
Hammami, Effects of Agronomic Application
of Olive Mill Wastewater in a Field of Olive
Trees on Carbohydrate Profiles, Chlorophyll a
Fluorescence and Mineral Nutrient Content.
Environ. Exp. Bot., 71, 2011, pp. 184–191.
[9] Beard, J.B., Turfgrass: Science and Culture,
Prentice Hall Engle wood Cliffs, N.J., 1973.
pp. 353-356.
[10] Morris, K.N., A Guide to NTEP Turfgrass
Ratings, National Turfgrass Evaluation
Program (NTEP), 2002, Beltsville, MD,
http://www.ntep.org.
[11] Karcher, D.E., and M.D. Richardson,
Quantifying Turfgrass Color using Digital
Image Analysis, Crop Sci., 43, 2003, pp. 943-
951.
[12] Ghali, I.E., G.L. Miller, G.L. Grabow, R.L.
Huffman, Using Variability within Digital
Images to Improve Tall Fescue Color
Characterization, Crop Sci. Vol. 52, 2012, pp.
2365–2374.
[13] Rusan, M.J.M., A.A. Albalasmeh, H.I.
Malkawi, Treated Olive Mill Wastewater
Effects on Soil Properties and Plant Growth,
Water Air Soil Pollut, 2016, 227:135.
[14] Montemurro, F., G. Convertini, D. Ferri, Mill
Wastewater and Olive Pomace Composta as
Amendments for Rye-Grass. Agronomie, Vol.
24, 2004, pp. 481–486.
[15] Alburquerque, J.A., J. Gonzálvez, D. García,
J. Cegarra. 2007. Effects of a Compost Made
from the Solid By-Product (“alperujo”) of the
Two-Phase Centrifugation System for Olive
Oil Extraction and Cotton Gin Waste on
Growth and Nutrient Content of Ryegrass
(Lolium perenne L.), Bioresource
Technology, Vol. 98, Issue 4, 2007, pp. 940-
945.
[16] Nektarios, P.A. N. Ntoulas, S. McElroy, M.
Volterrani, G. Arbis. Effect of Olive Mill
Compost on Native Soil Characteristics and
Tall Fescue Turfgrass Development Agron. J.,
Vol. 103, 2011, pp. 1524–1531.
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[17] Barbera, A.C., C. Maucieri, A. Ioppolo, M.
Milani, V. Cavallaro, Effects of Olive Mill
Wastewater Physico-chemical Treatments on
Polyphenol Abatement and Italian Ryegrass
(Lolium multiflorum Lam.) Germinability,
Water Research, Vol. 52, 2014, pp. 275-281.
[18] Mekki, A., A. Aloui, Z. Guergueb, M.
Braham, Agronomic Valorization of Olive
Mill Wastewaters: Effects on Medicago sativa
Growth and Soil Characteristics, Clean – Soil,
Air, Water, Vol. 46, 2018, 1800100.
[19] Harivandi, M.A., Interpreting Turfgrass
Irrigation Water Test Results, Pub. 8009,
University of California, Division of
Agriculture and Natural Resources, 1999, 9 p.
[20] Uddin, M.K., and A.S. Juraimi, Salinity
Tolerance Turfgrass: History and Prospects,
The Scientific World Journal, Vol. 2013,
Article ID 409413, 6 pages.
[21] Bargougui, L. Z. Guergueb, M. Chaieb, M.
Braham, A. Mekki, Agro-physiological and
Biochemical Responses of Sorghum Bicolor
in Soil Amended by Olive Mill Wastewater,
Agricultural Water Management, Vol. 212,
2019, pp. 60-67.
[22] Mekki, A, A. Dhouib, S. Sayadi, Evolution of
several soil properties following amendment
with olive mill wastewater. Progr Nat Sci, 19,
2009, pp. 1515–1521.
[23] Kokkora, M.I., C. Papaioannou, P. Vyrlas, K.
Petrotos, P. Gkoutsidis, C. Makridis, Maize
Fertigation with Treated Olive Mill
Wastewater: Effects on Crop Production and
Soil Properties, Sustainable Agric. Res., 4(4),
2015, pp. 66-75.
[24] Chaari, L., N. Elloumi, K. Gargouri, B.
Bourouina, T. Michichi, M. Kallel, Evolution
of Several Soil Properties Following
Amendment with Olive Mill Wastewater,
Desalination and Water Treatment, 52:10-12,
2014, pp. 2180-2186.
[25] Chartzoulakis, K., G. Psarras, M.
Moutsopoulou, E. Stefanoudaki, Application
of Olive Mill Wastewater to a Cretan Olive
Orchard: Effects on Soil Properties, Plant
Performance and the Environment,
Agriculture, Ecosystems and Environment,
138, 2010, pp. 293-298.
[26] Gargouri, K., M. Masmoudi, A. Rhouma,
Influence of Olive Mill Wastewater (OMW)
Spread on Carbon and Nnitrogen Dynamics
and Biology of an Arid Sandy Soil. Commun.
Soil Sci. Plant Anal., 45(1), 2014, pp. 1–14.
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The authors equally contributed in the present
research, at all stages from the formulation of the
problem to the final findings and solution.
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Scientific Article or Scientific Article Itself
No funding was received for conducting this study.
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The authors have no conflict of interest to declare.
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WSEAS TRANSACTIONS on ENVIRONMENT and DEVELOPMENT
DOI: 10.37394/232015.2023.19.42
K. Dragoidou, Α. E. Nikolopoulou,
M. Kοkkora, P. Vyrlas
E-ISSN: 2224-3496
456
Volume 19, 2023
