沙漠研究 22-1, 21 -24 (2012 )"ICAL 1 / DT X"

Journal of Arid Land Studies－Refereed Paper－

Soil Salinity Control through Halophytes in Arid andSemi Arid Area in Mauritania
Ould Ahmed BOUYA AHMED1)
Abstract: Soil salinity is one of the most serious agricultural problems. Cultivated area is rapidly decreasing in Mauritania due toconsecutive droughts and farmers’ migration to the cities. Desertification affects over 80% of the country’s lands due to climatechange and human activities. The annual precipitation varies from less than 50 mm to more than 300 mm. Low air humidity
combined with prevalent winds brings considerable loss of water due to evapotranspiration. Over grazing, improper traditional
agricultural methods and deforestation devastate the land resources. Moreover, the soil salinity is considering the most serious
problem face agricultural sustainability in Mauritania. In the arid and semi-arid regions of Mauritania, irrigated rice production, using
quality water (0.10 – 0.25 dS m-1), has led to rising groundwater levels and increases in soil water salinity (2.20 dS m-1 ) in the rootzone. However, improving soil saline requires two important considerations. First, the use of high efficiency irrigation systems andmanagement options and the second is prevent or minimize the degradation of soil resources through applying bioremediation
techniques. There are various kinds of halophytes acceptable to saline soil having specialized and distinguished environmental
characteristics. These halophytes plants i.e. Atriplex and Tamarix extract salt from soil to reclaim the land and produce importantbio-mass. This paper attempts to give an account of promising halophytes which can be grown in saline soil and their effectiveness incontrol of salinity. It also reports recommendations and further research needed for utilization of halophytes in combating salinity.
Key Words: Atriplex, Salt reclamation, Soil salinity

1. Introduction
Soil salinity is the major environmental stress and largely
causes yield losses of crops worldwide. This problem is moreacute in arid and semi-arid regions (Munns, 2002), wheresalinity strongly limits crop development. In the Senegal
River, irrigation water is mixed to native neutral saline waters
inherited from an ancient marine intrusion before the Diama
dam constructed (Ceuppens et al., 1997). The Diama Dam,located 23 km upstream from the river’s mouth, wascompleted in 1986 and its primary function is to prevent
salt-water intrusion from the Atlantic Ocean. The Diama Dam
is closed during the dry season from November to June, and isgradually opened during the rainy season, generally aroundJuly. Irrigation is usually gravity fed and the water
application efficiency is very low. Under dry and hot climaticconditions, irrigation can lead to land salinization.
The main crop grown in Mauritania under irrigation is rice.
The potential production of irrigated systems in the Mauritania
is large, but actual farmers’ yields are very low (less than3T/ha). Farmers are increasingly abandoning rice fields in
Mauritania irrigation schemes which are commonly attributed
to salinity problems. Irrigation is often practiced without

adequate drainage facilities. Salts may also be brought to thesoil surface in the off-season through capillary rise if the watertable is close to the soil surface. However, the needs forintroduction of new irrigation systems and improvements inexisting practices, at least in the intensive vegetable producing
regions, have been identified (Ould Ahmed et al., 2006).
Several workers (Ould Ahmed, et al., 2007; Fisher, 1980) haveindicated that when land turned saline attention should begiven for selection and use of appropriate irrigation systems
and practices that will supply just sufficient quantity of water tothe root-zone to meet the evaporative demand and minimize
salt accumulation in the root-zone (Fisher, 1980; Munns, 2002).
The second approach is to select crops/varieties that cantolerate salinity stress to a given degree (Claudivan et al., 2005).
Therefore, selecting plants tolerant to salinity is an alternative
strategy for a sustainable agriculture in these saline soil lands.
Meanwhile, soil reclamation could be done using
bioremediation method through planting halophyte plant which
can absorb salt from soil and utilize these plants as fodder.
Atriplex halimus subsp. schweinfurthii, a widely distributed
halophyte in the North Mauritania salt steppes, is of interest
because of its tolerance to environmental stresses and its
possibility to use as a fodder for livestock. The use of
halophytic plants in pasture and fodder production on saline
soils is the only economically feasible solution available (Khan* Corresponding Author: a_bouya@yahoo.com
P.O.Box 3800 Nouakchott Mauritania
1) Département de génie de l’agriculture et des biosystèmes, Institut Supérieur d'Enseignement Technologique (ISET) Rosso – Mauritania

and Duke, 2001). Therefore, this study was carried out toassess the salinity improvement using halophyte plant Atriplex.

500
Rainfall 2009450

Rainfall 2010
ETo 2009

400

ETo 2010

200
150
100
500JanFév

MarsAvril

Mai

Juill

JuinSeptAoût

Oct Novem Décem

Fig.1 Rainfall and potential evapotranspiraton at the study area.
Saline map before planting Atriplex Jan 2010
16.5248

16.52475

16.5247

16.52465

16.5246-15.7771-15.77705-15.777-15.77695-15.7769-15.77685-15.7768-15.7768

Saline map after one year Jan 2010
16.5248

16.52475

16.5247

16.52465

20-15.77705-15.77716

12-15.77695-15.7769-15.77685
2-15.7771

616.5246

10Atriplex halimus subsp. schweinfurthii grows in a brine-contaminated site in southeastern Mauritania (near to Senegal
River along 200 Km), where soil specific conductance varied
from 8-40 dS m-1. Atriplex is valued as livestock forage when
herbage availability is low especially in arid environments andsalt-affected area (Houerou et al., 1995) because they havehigh content of crude protein, vitamins (A, C and D) andminerals such as chromium (Shani et al., 1972; McKell C.M.
1989).
Potential evapotranspiration (ETo) and rainfall during 2009

250143. Results and Discussion

30018The experiment was conducted at the field located at theInstitute of Sciences and Technology (ISET) in Rosso,Mauritania. The soil in the study area is relatively uniform,
with clay soil being the most predominant texture clay 45%,
silt 40%, and sable 25%). The filed holding capacity is 0.33
cm3 cm-3 and wilting point is 0.18 cm3 cm-3. The soil is very
slow permeability approximately less than 6 mm/day.
Water quality of Senegal River is good and seems
consistent. Very low mineral content (18 µS/m electricalconductivity), pH neutral, it has SAR of less than 1. All
studies have classified as excellent and safe for irrigation(Boivin et al., 1998).
A randomized complete block design with two replications
was used in this study and control without plant. The
irrigation amount was based on evapotranspiration andleaching water was applied only during rainy season. The
amount of water was applied every two weeks. The densityof plant was two plants per square meter; each treatment plot
was 5 m × 5 m. The shout of plant was harvested every twomonths and mixed with grass and then gave to livestock (Goatsand caws).
The weather data was measured every hour using two
meteorological stations at the ISET. The average dailyreference evapotranspiration (ETo) was calculated with
Penman-Monteith equation. Soil electrical conductivity wasmeasured at depth 20 cm. The soil sample was taken fromgrid every 1 m. The ECe values were determined in alaboratory. For each sample, approximately 100 g of soil for
ECe measurement was dried, and saturated with distilled waterfor 24 h. The electrical conductivity of saturated paste extract(ECe) was measured using a calibrated conductivity meter(model SypHony SP80PI).

350mm/month )))2. Material and Method

84dS/mFig. 2. Electrical conductivity (ECe) profile at Atriplex treatment
during 2010 and 2011.

and 2010 are shown in Figure 1 indicated that ETo was very
higher compared to rainfall which may directly effect the soil
salinization. The higher evaporation may lead to transfer salt

Saline map at control Jan 2010
16.52496

18Control

16Atriplex

Average ECe (dS/m)))

16.52494

16.52492

16.5249

16.52488

16.52486

1412108
6416.52484

216.52482

0Jan-2010

Jan-2011

16.5248

Fig. 4. Average of ECe in 2010 and 2011.
16.52478-15.77676-15.77672-15.77668-15.77664-15.7766-15.77656

illistrated that with more Atriplex plant the amount of salt
decrease.
Figure 4 shows the average ECe values during experimentperiod. Data analysis show significantly remove of salt at
Atrilplex treatment (40%) compared to control (12%).
However, the infiltration rate is generally less than 6 mm/day,due either to poor soil permeability and/or to the rising of thewater table. This low infiltration rate may be dangerous forthe soils, as it favors salt accumulation, and could eventuallylead to soil salinization. More research on soil accumulation
impact as results of evapotranspiration and water table change
during growing Atriplex is needed to derive a better
understanding of salt accumulation.

Saline map after one year Jan 2010
16.52496

16.52494

16.52492

16.5249

16.52488

16.52486

16.52484

16.52482

16.5248

4. Conclusion and Recommendation
16.52478

2016

12-15.77668-15.77656

2-15.77664

61-15.77668

1-15.77672

1-15.77676

4dS/m

Fig. 3. Electrical conductivity (ECe) profile at control treatment
during 2010 and 2011.

in the upper layer. The shallow groundwater approximately
less than 3 m in the study area can be bring salt to upper soil
layer through capillary phenomena.
To compare the salinity concentration in the soil profile
after one year, the average ECe values were plotted in Surfer
8 (Golden Software, Inc.,) (Fig. 2).
The elctrical condactivity (ECe) in the soil profile showthat salt decrease after one year through planting Atriplex andapplying leaching during rainy season. Figure 2 shows thathigher salt concentration that were present initially weredispresed. Howerever, salt concentartion at the control shows
salt was less removed compare to Atiplex treatment (Fig. 3)

This study showed that Atriplex halimus subsp.
schweinfurthii was a highly salt-tolerant species and cangrowth in very higher soil salinity, therefore, can be used forbioremediation to improve soil salinity. The soil salinity wasimproved 40% under Atriplex treatment during one yearexperiment. There was no attempt in this experiment toestablish whether the Atriplex was negatively impacted by thesoil salinity but salinity accumulation where improved.
This study suggested further studies:- Relationship on salt reduction and Atriplex density.
- Study of salt reduction depth and leaching with growing
Atriplex.
- Salt concentration in the shouts weight and dry mater
relationship with soil salinity reduction.

References
Boivin P., Favre F., Maeght J.L. (1998): Les sols de lamoyenne vallée du fleuve Sénégal. Etude et Gestion desSols, 5: 235-246.
Ceuppens J., Wopereis M.C.S., Miézan K.M. (1997): Soilsalinization processes in rice irrigation schemes in theSenegal River delta. Soil Sci. Soc. Am. J., 61: 1122-1130.
Claudivan F.L., José C., Marco A.O., Hugo A.R. (2005):
Changes in growth and in solute concentration in sorghum
leaves and roots during salt stress recovery. Environ. Exp.
Bot., 54: 69-76.
Fisher R.A. (1980): Influence of water stress on crop yield insemiarid regions. In Turner, N.C., Kramer, P.J. Eds., CropWater Requirements. Conf., September 11–14 1984, Paris,INRA, Paris, pp. 221-234.
Houerou H.N.K., Le Houerou H.N., Choukr Allah R.,
Malcolm C.V., Hamdy A. (1995): Forage halophytes in theMediterranean Basin. Halophytes and Biosaline
Agricultures, 115-136.
Khan M.A., Duke N.C. (2001): Halophytes - A resource for thefuture. Wetlands Ecolo. Manag., 6: 455-456.
McKell C.M. (1989): The biology and utilization of shrubs.
AcademicPress, Inc., San Diego, CA, 656 p.
Munns R. (2002): Comparative physiology of salt and waterstress. Plant Cell Environment, 25(5): 659-662.
Ould Ahmed B.A., Inoue M., Moritani S. (2010): Effect saline
water irrigation and manuring on available water content,salinity of soil, and the growth of wheat. Agricultural Water
Management journal, 97: 165-170
Ould Ahmed B.A., Yamamoto T., Rasiah V., Inoue M.,
Anyoji H. (2007): The impact of saline water irrigation
management options in a dune sand on available soil waterand its salinity. Agricultural Water Management, 88: 63-72.
Shani J., Ahronson Z., Sulman F.G. (1972): Insulin-potentiating
effect of saltbush (Atriplex halimus) ashes. Isr. J. Med. Sci.,
8: 757-758.