1. Sustainable Options for Soil and water salinity management in date palm production
Nazir Hussain, Osman El-Sharief Abdalla, Muhammed Salem Al-Bakri Al-Yafai and Talaat Ahmed
Section of Agricultural Research and Extension
Department of Agricultural Affairs
Ministry of Environment
Doha, State of Qatar

2. Components of my discussion
Date palm production and yields, the past and present
Future climatic changes with respect to salinity/ sodicity and date palm production
Extent of salinity in major date palm producing countries
Management strategies for soil and water salinity
Conclusions

3. Average yield (T ha-1) of date palm of the top 10 Countries during the last five decades
2010
2005
2000
1990
1980
1970
1961
Countries
6.277
5.850
6.200
5.496
7.444
7.137
7.720
World
32.255
33.428
34.736
24.842
22.300
16.950
23.950
Egypt
4.608
8.080
8.473
4.412 -
Iraq
6.334
4.054
4.088
6.385
9.194
12.500
12.000
Saudi Arabia
4.181
6.056
7.793
6.838
8.044
8.503
8.270
UAE
5.815
Pakistan
Compiled from FAOSTAT Data by the Authors

4. Average yield (T ha-1) of date palm of the top 10 Countries during the last five decades (contd.)
2010
2005
2000
1990
1980
1970
1961
Countries
4.002
3.491
3.652
2.618
2.996
2.477
2.500
Algeria
6.533
4.173
4.707
4.339
3.049
3.875
3.841
Iran
11.905
9.764
9.495
7.0097
10.004
6.000
6.023
Sudan
8.816
7.886
4.800
3.482
3.462
3.077
Oman
5.367
5.357
5.000
4.933 -
Libya
Compiled from FAOSTAT Data by the Authors

5. The Causes of Diminishing Yields
Deficiency of irrigation water of good quality and appropriate irrigation system
Soil and water salinity
Low yielding cultivars
Insect and disease attack
Poor agronomic techniques practiced by the farmers
Harvesting losses and post harvest cares
Poor awareness of the date palm growers, need of training and hampered technology transfer to the end users

6. Future Global climatic changes to be expected
Rise in temperature and evaporation
The hydrological cyclones and floods
Excessive or meager rainfall
Increase in droughts
Rising of mean sea level
Melting of ice
Dry regions of the world would become still more drier
It may become more difficult for water scarce countries to cope with natural conditions with lesser water than what is now available (Bino, 2008).
Most of the above happenings, if not all, are expected in date palm growing countries

7. Expected climatic changes and salinity
Soil and water salinity are the problems of arid and semi arid regions because these are directly associated with levels of precipitation and temperature
More use of saline water under lesser rainfall and subsequent drought
The salts added/ recycled through irrigations remain in the profile and come to the surface or subsurface with the capillary movement of soil water when dry conditions coupled with high temperature persist
The water evaporates and leaves dissolved salts on the surface or just underneath
When such a process continues for longer periods the consequence is salinization (accumulation of salts) followed by sodication (Substitution of Ca + Mg by sodium on the clay complex)
Thus, increase in impact of salinity/ sodicity is expected under the scenario of such climatic changes

8. GLOBAL SCENARIO OF THE SALINITY PROBLOM
Soil salinity and sodicity are the global problems that encompass all the continents except Antarctica.
World soil map prepared by FAO/UNESCO indicated that total saline lands occupy 397 million ha while sodic lands are spread on an area of 434 million ha.
Out of the current 230 million ha of irrigated land of the world, 45 million ha (19.5 %) are salt affected.
Salt affected area within dry land agriculture has been reported as 32 (2.1 %) out of total 1500 million ha.

9. Some facts about salinity in Arab World and GCC countries
UAE mha
KSA mha
Oman mha
Qatar ha
Bahrain ha
Kuwait ha
Yemen mha
Salt affected area in Arab world is 82.7 mha (42 % of arable land that is 14.1% of total)
Egypt mha
Iraq mha
Sudan mha
Tunisia mha
Algeria mha
Morocco mha
Libya mha

10. Effects of salinity on plants
1. OSMOTIC EFFECTS
Loss of turgor
Reduced water uptake even in the presence of water
Reduced uptake of nutrients
2. SPECIFIC ION EFFECT
Toxicity of chlorides and sulphate of Na.
Toxicity of Boron and Mg.
Plant functions (Photosynthesis, respiration and photophosporylation etc.)
Membrane leakage
Inhibition of enzyme activities

11. Effects of salinity on plants
NUTRITIONAL IMBALANCE
More uptake of Na, Ca , Mg, Cl and SO4
Less uptake of K and P
Reduced availability of K, P, N, B, Zn, Cu, Fe
FINAL EFFECTS
General paleness
Reduced or stoppage of growth
Partial or total death of Plants
More sterility
Low or no yields

12. Tolerance of Date palm to salinity (EC dS/ m)
0% yield
50% yield
75% yield
100% yield
Type of sanity
21.0
12.0
7.3
2.7
Water salinity (Ayers and Westcot, 1985)
32.0
18.0
11.0
4.0
Soil salinity
(Ayers and Westcot, 1985
Growth of seedlings -
9.0
3.0
Water salinity in sandy loam soil
(Al-Rasbi et al., 2011)

13. Date Palm Orchard Affected by Salinity in Oman

14. Date Palm Orchard Affected by Salinity in Oman

15. Causes of salinity in the region
Climatic conditions: Low rainfall and high temperature results in surface and subsurface accumulation of salts (Salinization)
Nearness to sea: Seawater sprays, floods and intrusions
Secondary salinity mostly emerging from consistent use of saline water, presently it is the major source of development of salt affected soils in the region
Blind and unforeseen pumping of groundwater resulting in destroying the balance (of centuries) existing between recharge and stored good quality water
Mismanagement of irrigation water and salt affected soils

16. Negative effect of saline water on plant parameters of date palm (% decrease over control = 3 dS/ m)
Trunk girth
Leaf length
Number of fronds
Plant height
Water EC ds/ m - 3 11 8 12 18 6 17 27 28 9 21 32 36 40 29 39 46 15 48 53

18. Precautionary Measures
Safe usage of brackish water through appropriate management strategies in order to control secondary salinity
Plowing of lands to break the capillaries and keeping boundaries of fields strong, especially before starting of monsoon season and occasional deep plowing
Mulching to decrease evaporation and resultant salt accumulation
Green manuring/ composting and addition of organic matter
Scheduling of irrigations
Addition of amendments (Gypsum, sulphuric acid etc.) if the irrigation water is sodic as well

19. Safe utilization of saline water
Utilization of saline water continuously for longer periods causes salinization and deleterious effects appear on
Crops Soils Environment
Therefore, management of saline water is highly important
In fact, salinity management depends upon management of saline waters
Under the prevailing conditions of Arabian Peninsula, appropriate and important strategies are:
1. Leaching fractions Cyclic use
3. Application of organic matter Mulching

20. Leaching Fractions The EC of water and its used quantity
Salts can accumulate slowly and gradually depending upon
The EC of water and its used quantity
Rainfall and temperature
Soil parameters like texture and drainage
Leaching of salts can only occur if additional water over and above the consumptive water of various crops is applied
This additional water is called leaching fraction (LF) or leaching requirement
This is the only solution when saline water is solely available
Investigations in Oman indicated partial success of the technique (When EC of water is not too high = 9 dS/ m or above)

21. Role of leaching fractions in improvement of growth character of date palm seedlings when irrigated with saline water

22. Effectiveness of leaching fractions in controlling increase in soil EC during irrigation with saline water

23. Application of organic matter
Low organic matter is the peculiarity of soils of arid and semiarid regions but it is very particularly true for Arab Peninsula
Soils are mostly sandy and have high drainage that does not permit holding water for longer periods
The applied irrigation water disappears in couple of days leaving the lands dry and plants to suffer for water
Organic matter is the only rescue of such conditions because soil physical properties including water holding capacity are improved due to its application
Manuring and surface mulching indicate significantly higher soil moisture content requiring less irrigations
Resultantly, there will be less addition of salts when water is saline and lesser salinization
Organic matter of plant residues or from animals may be the best option.

24. Efficiency of organic matter application in maintaining plant growth parameters during saline water irrigation

25. Effectiveness of organic matter application for controlling increase in soil EC during irrigation with saline water

26. Mulching to reduce salinization
High temperature generally results in high evaporation which causes twin effect; enormous water losses and enhanced salt accumulation in arid and semiarid regions
Providing mulch on the surfaces checks water losses and simultaneous salt concentration
The major objective of mulching is conserving moisture after irrigations and thus saving water in the long run, although it subsequently reduces salt accumulation as well
The mulch may be plastic, polythene, soil or organic residues
Studies on mulching in Oman established its usefulness

27. Effect of mulching and saline water on soil EC (dS/ m)
Means
Date palm
Residue
Plastic cover
Control
Water
Salinity
(dS/ m)
2.22 B
1.63 bc
1.06 c
3.98 bc 3
6.39 A
4.35 b
3.27 bc
11.56 a 6 -
2.99 B
2.16 B
7.77 A

28. Soil Salinity Management
Analyzing the specific soil, water and climatic conditions of the region), following techniques can be recommended
Application of organic matter (especially composted crop residues and animal manures) that can increase water holding capacity of soil, decrease demands for irrigations and could reduce salt accumulation
Leaching of salts through appropriate water quality, quantity and leaching method
Selection of suitable varieties that can match salinity level and other soil properties of the growing site (texture, structure, calcareousness, fertility and drainage)

29. Soil Salinity Management
Irrigation system well suited to quality of water, soil texture and drainage, Bubbler is just like flood and may be replaced with subsurface irrigation system
Two to three flood irrigations during land preparation before transplantation of date palm saplings and prior shifting to modern/ bubbler irrigation system for leaching down the accumulate salts in the soil surface
The above practice can be useful if adopted after every quarter to leach down the accumulated salts and keeping soil EC lower when irrigation water is saline
Breaking capillaries by hoeing and mulching to reduce evaporation and accumulation of salts, especially in loam and clay loam soils

30. LEACHING OF SALINE SOILS
The saline soils can be rehabilitated through leaching by good quality water (or at least having lesser EC than the soil). At the steady state the soil will have same EC as that of leaching water provided that soil drainage is good (as existing in Gulf countries). The most appropriate equation to calculate quantity of water required for leaching can be that of Hillel (2000). Of course, salt tolerance of crops to be grown will be important consideration
C/ Co = k/ (d/ ds)
Where
C= Salt concentration to be obtained in the leached soil
Co = Initial salt concentration in the soil
D = Depth of leaching water
Ds = Depth of the soil to be leached
k = an empirical coefficient (0.1 for sandy soils)

31. CONCLUSIONS The management practices that can be adopted are:
The success of management of salinity in Arabian Peninsula and other date palm growing countries depends upon minimum possible use of saline water and controlling salt accumulation
The management practices that can be adopted are:
Matching of salt tolerance of date palm varieties with the salinity status of soil is the key of success. Alternatively, soil salt level must be reduced through leaching with good quality water or at least water having lesser EC than the soil to be rehabilitated
The quality of saline water and soil EC must be monitored during date palm growth and site specific measures like; appropriate leaching fractions, application of organic matter/ soil conditioners, mulching and suitable agronomic practices be adopted
If saline water is the only option then packages of practices for date palm growing must match site specific conditions of soil, water and climate and the salt tolerance of variety

32. Future research required
Future research in the region on all aspects of salinity should not only be strengthened but also be directed to remove past deficiencies
The site specific case studies of leaching fractions for various qualities of saline water to be used for different varieties of date palm are of particular importance
Identification/ evolution of salt tolerant varieties/ cultivars is another important area in this regard
Management practices like cyclic use of saline and good quality water have to be investigated
Interactions of high temperature and saline water irrigation should be of particular interest in the scenario of climatic changes

33. Policy decisions
Wise policy decisions by the respective governments can balance the situation and put date palm farming on the right track which can not only increase regional production (going very rapidly down and down due to salinity) but can also be capable of meeting future challenges
Salinity research not only be strengthened but organization should be established at country and regional level which should only be dealing with the salinity subject
Universities of the region should play a leading role in this regard and must be provided with finances and the expert manpower