




































In ternationa l
Scholars
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African Journal of Environmental Economics and Management ISSN 2375-0707 Vol. 8 (4), pp. 001-006, April, 
2020. Available online at www.internationalscholarsjournals.org © International Scholars Journals 

 

Author(s) retain the copyright of this article. 
 
 
 

Full Length Research Paper 

 

Purslane and natural vegetation as bioremediation 
tools to cope salinity in Satsuma mandarin orchards 

 
Cenk Ceyhun Kılıç1*, Dilek Anaç2, Uygun Aksoy3 and Süer Anaç4

  
1
Bayindir Vocational School, Ege University, 35840 Bayindir, Izmir, Turkey. 

2
Department of Soil Sciences, Faculty of Agriculture, Ege University, 35100 Bornova, Izmir, Turkey. 
3
Department of Horticulture, Faculty of Agriculture, Ege University, 35100 Bornova, Izmir, Turkey. 

4
Department of Farm Structures and Irrigation, Faculty of Agriculture, Ege University, 35100 Bornova, Izmir, Turkey. 

 
Accepted 26 October, 2019 

 
The objective of this study is to compare the Na and Cl removal capacity of natural vegetation (spontaneous flora) and 
cultivated purslane, as bioremediation techniques to overcome salinity in Satsuma mandarin plantations. An 
experimental orchard was established on two different rootstocks, (Poncirus trifoliata L.) Raf. and Troyer citrange 
(Poncirus trifoliata × Citrus sinensis)) and the orchard was irrigated at 2 different salinity levels (0.65 and 5 dSm

-1
.The 

ground of the on rows of Satsuma mandarin trees was kept either with its natural flora (vegetation) or with cultivated 
purslane. Results are statistically examined with respect to the effects and interactions between the tested factors; 
rootstock, salinity and remediation tools. Biomass yields of the tested alternatives (natural vegetation and purslane) 
and their Na, Cl, K and Ca concentrations were measured. Also Na and Cl concentrations of mandarin leaves were 
analyzed to examine the remediation effect. Results showed that yield depressions of the natural vegetation plots 
were higher compared to purslane and showed a considerable difference according to the rootstock. Sodium removal 
of purslane and natural vegetation was found to be similar. Chloride uptake was lower in Troyer citrange compared to 
P. trifoliata. Purslane and/or natural vegetation can equally be recommended as Na removing bioremediation crops. 
Purslane can also be recommended as a promising Cl remover suitable for orchards on P. trifoliata (L.) Raf. rootstock. 

 
Key words: Bioremediation, natural vegetation, purslane, salinization, satsuma mandarin. 

 
INTRODUCTION  
 

Large areas of arable land are being abandoned each 
into  the  roots  or  the  vascular  system  (Walker  and 
year due to misuse of  soils like salinity (Essa,  2002). 
Douglass,   1983).   The  exclusion  capacity   can  be 
Bioremediation  of  the  degraded  crop  land  is  an 
correlated with the sterol of roots (Maas, 1993). 
environmentally and ecologically friendly practice. Salinity 
Calcium (Ca)  maintains  the  structural  integrity  and 
causes physiological and biological disorders like osmo-
selective permeability of root  membranes  (Hanson, tic, 
toxic or ionic imbalances in the plant body (Mengel 1984). 
The effect of salinity on nutrient composition of and Kirby, 
2004). plant tissues, especially the concentration of Ca 
and K Chloride (Cl) and sodium (Na) are For citrus 

orchards, the bioremediation of  the land  under risky ions 

  
 
*Corresponding author. E-mail: cenk.kilic@ege.edu.tr. Tel: 
+90 exclude Cl or Na from the scions (Maas, 1993). 232 
581 63 17. Fax: + 90 232 581 71 75.  

in planthas been extensively investigated (Munns, 2002; 
Essa, growth  under  excess  salinity  conditions.  Sodium  
tole-2002). The   authors   reported   that   relatively   high 
rance seems to involve the ability of xylem parenchyma 
concentrations of Ca and K are essential for a successful 
cells to extract Na from the xylem stream and sequester it 
growth in a saline environment. in the woody root  and 
stem  tissues (Hepaksoy et  al., One cost effective 
friendly method to cope with salinity 1999). Chloride 
tolerance of plants can be heritable and is  to  grow  salt  
tolerant  species,  varieties  or  to  use be heritable and 
exclusion of Cl seems to be controlled rootstocks 
tolerant/resistant to saline conditions. Citrus in primarily 
by root membranes that either restricts Cl  entry general  
are  very  sensitive  to  salinity.  In  this  regard, rootstock-
scion relations have been extensively studied (Aksoy et 
al., 2000; Hepaksoy et al., 1999). It is reported that citrus 
rootstocks considerably vary in their ability to salinity  



 

 
 
 
 

 

threat could be done by using salt removing crops either 
as cover crops or as intercrops between or on the tree 
rows or by leaving the ground with its natural flora 
(vegetation) to enhance salt uptake. Kumamoto et al. 
(1990) and Grieve and Suarez (1997) rated purslane as a 
very good salt removing crop according to Mass and 
Hoffman (1997). However, not much information is 
available for the salt removing capacity of natural 
vegetation under Mediterranean conditions. Nazik (2007), 
Bilen (2008) and Unal (2009) specified the yearly 
differences in the dominant natural vegetation species 
and reported that spontaneous vegetation can change 
yearly due to climatic conditions, main crop and fertili-
zation. Bilen (2008) highlighted that under Mediterranean 
climate conditions, Capsella bursa-pastoris is found as 
the dominant flora when long term annual average preci-
pitation was not reached. However, when the rainfall is 
not restricted, Lamium purpureum is found to dominate.  

The main objective of this study was to compare Na 
and Cl removal capacity of natural vegetation (sponta-
neous flora) and the cultivated purslane (underlying inter-
crop) as saline bioremediation techniques for Satsuma 
mandarin trees budded onto two different root-stocks, 
Poncirus trifoliata and Troyer citrange. The study also 
aimed at determining the biomass yields, K and Ca 
content of these two tested alternative underlying crops. 
In order to make a better evaluation, Satsuma mandarin 
leaves were also analyzed for their Na and Cl contents 
with the purpose of measuring their tissue concentrations 
under different intercrop, rootstock and salinity conditions. 
 
 

 
MATERIALS AND METHODS 
 
Satsuma mandarin (Citrus unshiu Marc var. Owari) is a well-known 
Citrus species which ripens early in the season. An experimental 
plot of 0.45 ha located at Ege University Campus (Izmir/Turkey) 
was continuously irrigated with saline water for 13 years. The 
Satsuma mandarins were budded on two different rootstocks, 
Trifoliate orange (P. trifoliata (L.) Raf. and Troyer citrange (P. 
trifoliata × Citrus sinensis).  

The plots were irrigated during the dry period (May to November) 

at 2 different salinity levels (0.65 dS m
-1

 (nonsaline treatment (fresh 

water) and 5.0 dS m
-1

 (saline treatment)) via double line source. 
Fresh water from a deep well was supplied through one line and 
highly saline stock solution was distributed through the second line. 
The drippers were pressure regulated and their discharge rate was 

2.3 L h
-1

. Irrigation was applied weekly based on previous day’s 
evaporation from USWB class A evaporation pan and the crop 
coefficient was used as 0.5 (Doorenbos and Kassam, 1979).  

Two different bioremediation tools were tested in the citrus plot, 
as natural vegetation and purslane. Experimental soils were sandy 
loam in texture with low calcium carbonate. Organic matter, N, P 
and K were sufficient. The EC and pH of the saturation extracts of 
the salinized and non salinized plots were 2.0 to 7.8 dS/m and 5.65 
to 7.70 at the beginning of the study. For one season, the ground of 
the on rows of Satsuma mandarin trees was kept either with its 
natural flora (vegetation) or with purslane. In the purslane (P. 
oleracea L.) plot, the seeds were sown on a row 25 cm distant from 

the tree trunk, at a seeding intensity of 2 to 3 kgha
-1

 (0.2 to 0.3 g m
-

2
 seed). Purslane was harvested as recommended, 70 days after 

 
 
 
 

 
 
 
 
emergence before the formation of new seeds (Vural et al., 2000). 
Similarly, in the natural vegetation plot, wild species were allowed to 
grow spontaneously for about 120 days till the new seeds appear. The 
major species in the natural flora were identified by square frames (25 
cm × 25 cm) which were randomly placed 5 times for each plot 

corresponding to a total sampled surface of 1 m
2
 and their intensities 

(number per unit area m
2
) were determined. In non salinized as well as 

salinized plots, number of Urtica urens (Stinging nettle) plants per unit 
area was the highest followed by Malva sylvestris (Mallow) and 
Calendula arvensis (Pot marigold). Generally Urtica emergence ranged 
from 41 to 91 per unit area.  

The experimental design was split-split plot with 3 replications, 
the main factor being the rootstock, second salinity of irrigation 
water and third the bioremediation tool. Total fresh weight (bio-

mass) of the harvested natural vegetation (g m
-2

) and the purslane 

(g plant
-1

) were weighed and their Na, Ca and K concentrations (% 
dry matter) were measured flamephotometrically and Cl 
potentiometrically (Kacar, 1972).  

After the irrigation, Satsuma mandarin leaf samples were taken 
at the end of October to the beginning of November (Chapman and 
Pratt, 1961) and also analyzed for their Na and Cl contents 
according to the above stated standard methods (Kacar, 1972).  

The paper presents the changes in biomass yield, Na, K, Ca and 
Cl concentrations of the natural vegetation and purslane and Na 
and Cl concentrations of Satsuma mandarin leaves. Results are 
statistically examined with respect to the effects and interactions 
between the tested variables; rootstock, salination and remediation 
tools as natural vegetation and purslane. All the statistical analysis 
was done separately for purslane and natural vegetation for tested 
factors. The data obtained was subjected to analysis of variance 
(ANOVA) and the mean differences were compared by LSD tests 
(Açıkgöz et al., 2004). 
 

 

RESULTS 

 

Biomass yield of purslane and natural vegetation 

 

The main effects of salination and rootstocks on the 
biomass yield of purslane and natural vegetation (flora) 
and their interactions were statistically significant. Yield 
changed with respect to these factors (Table 1).  

The relative yield depressions due to salination in 
purslane grown under Satsuma mandarin trees were 
close to each other, being 51% in the case of P. trifoliata 
rootstock and 57% in Troyer citrange compared to the 
yield obtained under non saline control conditions. 
Therefore, the difference between the yield depressions 
of purslane can be accepted as slight. On the other hand, 
the relative yield depressions of the natural vegetation 
were 78.5 and 61.6% for P. trifoliata and Troyer citrange 
rootstocks, respectively (Table 1). 

 

Sodium, Cl, Ca and K Concentrations of purslane and 
natural vegetation 
 
Sodium 

 

Main effect of salination and rootstock on Na concen-
tration of purslane was found to be statistically significant. 
On the other hand, Na concentration of the natural vege-  
tation was affected only by  salinity. The Na concentrations 



 
 
 

 

Table 1. Biomass of purslane (g plant
-1

) and natural vegetation (g m
-2

) as a function of salinity and rootstocks. 
 

Rootstocks Salinity level Fresh weight purslane (gplant
-1

) Fresh weight natural flora (g m
-2

) 

P. trifoliata Non-salinized parcel 26.73
a
 2248

a
 

 Salinized parcel 13.72
b
 1766

b
 

T. citrange Non-salinized parcel 91.28
a
 4860

a
 

 Salinized parcel 52.36
b
 2994

b
 

LSD(0.05) (Salt × Rootstocks) 3.21** 85.11** 
 

**P<0.01. Means in the same column followed by different letters are significantly different (p≤0.05). 
 

 

Table 2. Tissue Na (mg kg
-1

) concentration of purslane and natural vegetation and as a function of salt.  
 

 
Salinity level 

P. trifoliata  T. citrange 
 

 

Purslane Natural flora Purslane Natural flora 
 

  
 

 Non-salinized parcel 957
b
 522

b
 957

a
 609

b
 

 

 Salinized parcel 1218
a
 1479

a
 2000

a
 2050

a
 

 

 LSD(0.05)  31.01**  1185.59* 
 

 
**P<0.01, *P>0.05. Means in the same column followed by different letters are significantly different (p≤0.05). 

 

 
Table 3. Tissue Cl (%) concentration of purslane and natural vegetation as a function of salinity.  

 
 

Salinity level 
P. trifoliata T. citrange 

 

 

Purslane Natural flora Purslane Natural flora 
 

  
 

 Non-salinized parcel 0.41
a
 0.05

b
 0.47

a
 0.18

b
 

 

 Salinized parcel 0.46
a
 0.15

a
 0.67

a
 0.70

a
 

 

 LSD(0.05)  0.072*  0.46* 
 

 
*P<0.05. Significantly different (p≤0.05). 

 

 

of the two tested salt removing crops purslane and 
natural vegetation also differed.  

The effect of salination on purslane grown under 
Satsuma mandarin trees on P. trifoliata rootstock showed 
higher tissue Na contents under saline conditions. Similar 
condition existed in the case of Na measurements of the 
natural vegetation. The effects of salination on purslane 
and natural vegetation grown under the other rootstock, 
Troyer citrange were determined as significant at 5% 
level that is higher Na concentrations were analyzed 
under saline conditions (Table 2). When numerically eva-
luated, the natural flora grown under the satsuma trees 
on Troyer citrange rootstock had higher Na content. 
 
 
Chloride 

 

Main effects of salinity and rootstock on Cl concentrations 
of purslane were found to be significant. In the case of 
natural vegetation, only the effect of rootstocks was 
statistically significant. The Cl concentrations of the two 
remediation tools, purslane and natural vegetation, varied 

 
 

 

according to the treatments tested in the study.  
The effect of salinity showed higher Cl concentrations 

in both purslane and natural vegetation under both 
rootstock plots. The difference was significantly (5%) 
higher in the case of natural vegetation (Table 3).  

The effects of rootstocks put forth that the Cl of 
purslane and natural vegetation grown under the trees on 
T. citrange rootstocks were respectively higher than 
those grown under the canopy of the trees on P. trifoliata 
rootstocks (Table 3). 
 

 

Potassium 
 
Significant effects of salinity and rootstock were deter-mined 

on K concentrations of purslane and of natural vegetation. 

Significant statistical interactions were found for the cases of 

P. trifoliata and T. citrange, salinity × remediation tools. 

Under salinized conditions, K con-centrations of purslane 

and natural vegetation decreased.  
The level was almost 50% of the non-salinized 

conditions in case of purslane. 



 
 
 

 
Table 4. Tissue K (%) contents of purslane and natural vegetation as a function of salinity.  

 

Salinity level 
P. trifoliata Troyer citrange 

 

Purslane Natural flora Purslane Natural flora 
 

 
 

Non-salinized parcel 1.30
a
 1.20

a
 1.47

a
 1.24

a
 

 

Salinized parcel 0.64
b
 0.84

b
 0.77

b
 0.88

b
 

 

LSD(0.05)  0.118**  0.038** 
 

 
Means in the same column followed by different letters are significantly different (p≤0.05). 

 
 

 
Table 5. Tissue Ca (%) concentration of purslane and natural vegetation as a function of salinity levels.  

 
 

Salinity levels 
 P. trifoliata T. citrange 

 

 

Purslane Natural flora Purslane Natural flora 
 

  
 

 Non-salinized parcel 0.41
a
 1.05

a
 0.43

a
 1.25

a
 

 

 Salinized parcel 0.31
a
 0.68

b
 0.38

a
 1.08

b
 

 

 LSD(0.05)  0.168*  0.140* 
 

 
*P<0.05. Means in the same column followed by different letters are significantly different (p≤0.05). 

 
 

 

Results related to non-salinized control conditions 
showed that K of the purslane under Satsuma trees 
budded onto P. trifoliata was lower than the trees where 
Troyer citrange was used as the rootstocks Potassium 
concentrations of the natural vegetation grown under 
trees on both rootstocks were similar when there is no 
salinity problem (Table 4). 
 

 

Calcium 

 

Calcium concentration of purslane was affected only by 
the increase in salinity levels. On the other hand, natural 
vegetation was significantly under the effect of both 
salination and rootstocks (Table 5).  

The purslane and the natural vegetation under 
Satsuma mandarin trees with P. trifoliata as the root-
stocks had lower Ca concentrations compared to that of 
those under Troyer citrange. Natural vegetation always 
had higher Ca than that of purslane. 
 
 

 

Leaf Na and Cl concentrations of mandarin trees 

 

The leaf Cl concentrations of Satsuma mandarin trees 
were found to be significantly higher in the salinized 
parcels on both of the rootstocks.  

In general, similar behavior was determined for the Na 
contents of leaves which were also analyzed higher in the 
salinized trees.  

Satsuma mandarin leaves had higher Cl concentrations 
on P. trifoliata than that of Troyer citrange. On Troyer 
citrange higher leaf Na levels were determined (Table 6). 

 
 
 

 

DISCUSSION 
 
Biomass production of purslane and natural vegetation 
plots under Satsuma mandarin trees budded onto P. 
trifoliata and Troyer citrange rootstocks were negatively 
affected by salinity. Many researchers (Maas, 1990; Kılıç 
et al., 2008) state similar findings supporting the results 
of the present study. Relative yield depressions due to 
salinity were found around 50% for purslane plots under 
these two rootstocks. On the other hand, yield 
depressions of the natural vegetation plots were higher 
and showed a considerable difference according to the 
rootstock.  

Sodium generally does not damage the plants as does 
the Cl (Maas, 1993). According to the result of this study, 
Na removal of purslane and natural vegetation was found 
similar even if the rootstocks differed. It is known that 
Troyer citrange is a Na includer that is, excess uptake 
with no damage (Maas, 1990). In this case, higher Na 
concentrations measured in the leaves of Satsuma 
mandarin trees on Troyer citrange rootstock confirm this 
finding.  

Maas (1993) and Kılıç et al. (2008) highlighted purslane 
as a strong Cl removing crop. Mengel and Kirby (2004) 
state P. trifoliata as Cl sensitive. The critical leaf Cl 
concentration for Satsuma mandarins budded on this 
specific rootstock is indicated to change between 0.20% 
(Chapman, 1968) and 0.70% (Cohen, 1976). Our 
laboratory results related to high Cl in the leaves of 
Satsuma mandarin trees on P. trifoliata also fall within 
this range. On the other hand, findings in relation to 
Troyer citrange showed some differences. The low Cl 
contents measured in the leaves of Troyer citrange can 
indicate its low uptake and exclusion more via roots. 
Consequently, it can be claimed that the residual Cl in 



 
 
 

 
Table 6. Sodium and chlorine concentrations of mandarin leaves as a function of salt and rootstocks. 

 

 
Salinity levels 

 Cl (%) Na (mg kg
-1

) 
 

 

P. trifoliata T. citrange P. trifoliata T. citrange 
 

  
 

 Non-salinized parcel 0.12
b
 0.08

b
 386

b
 396

b
 

 

 Salinized parcel 0.75
a
 0.23

a
 728

a
 946

a
 

 

 LSD(0.05) 0.053**  5.971**  
 

 
**P<0.01, *P<0.05. Means in the same column followed by different letters are significantly different (p≤0.05). 

 

 

the soil is highly taken up by the natural vegetation under 
tree canopy. This assumption is in accordance with Cl 
results analyzed in the tissues of natural vegetation plots. 
Under saline conditions, the effect of the underlying crop 
kept on the orchard ground can be significant in K losses 
due to the nutrient competence with the satsuma 
mandarin trees. The tested bioremediation tools, purslane 
and natural vegetation, responded more or less similarly 
in their K removal from the rhizosphere.  

The excess Ca uptake from the growing environment 
of citrus trees can be effectively eliminated by a suitable 
rootstock. The underlying plant is important as well. In the 
present study, natural vegetation was found suitable in 
removing the highest amount of Ca from the soil. Kılıç 
(2005) reports a small difference between Ca uptake of 
P. trifoliata and Troyer citrange rootstocks, generally the 
latter having higher uptake rate. 

 

Conclusion 
 
It is concluded that purslane and/or natural vegetation 
can equally be accepted as Na removing bioremediation 
tool(s) for Satsuma orchards established either on P. 
trifoliata or on Troyer citrange rootstocks. It is also 
concluded that for Cl remediation, purslane could be a 
suitable accumulator plant in orchards on P. trifoliata 
rootstock which is susceptible to Cl due to its high uptake 
affinity. Moreover, relatively lesser yield depressions in 
relation to Cl hazard once again showed that purslane 
could be suggested for P.trifoliata. On the other hand, 
under Mediterranean conditions, natural vegetation could 
be recommended for Satsuma mandarin trees budded on 
to Troyer citrange rootstock. Troyer citrange rootstock 
excludes the excess Cl via its roots. 
 

 

ACKNOWLEDGEMENT 
 

The research work was partially supported by the INCO-
DC programme of the commission of the European 
communities, contract number: ERBIC18CT 980266. 
 

 
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