Time

43 Water is an invaluable natural resource, and the agricultural sector consumes nearly 70% of the country’s freshwater resources. The aquastat survey conducted in 2008 points out that nearly 913.2 million m³ water is abstracted every year in Kuwait, which includes irrigation and livestock (54%), municipalities (44%), and industry (2%). Of the 54% of water used for agriculture, 80% is for productive agriculture, 9% for landscape features and 11% for garden watering [5.6].

In Kuwait, good quality water is limited and the seasonal water balance, i.e. the difference between rainfall and evaporation, is invariably negative and imposes severe demands on the availability of water for agriculture. The groundwater in Kuwait is mostly saline, with limited amounts of fresh and brackish water [5.7]. The quantity and quality of groundwater is deteriorating due to the continuous pumping of water. Irrigation water contains soluble salts which accumulate on the soil surface and in the root zone on application, so that poor water quality is one of the major factors affecting soil salinity [8]. Based on its soluble salt content, groundwater is divided into fresh groundwater (<1000 mg/l), brackish groundwater (1000 to 7000 mg/l) and saline groundwater (7000 to 12 000 mg/l). Fresh groundwater and saline groundwater are not used for agricultural purposes, as the former is stored in freshwater reservoirs for drinking water, and the latter contains an excessive concentration of soluble salts [5.6]. As a result, brackish groundwater is used for agricultural and domestic purposes and when not properly managed, may exacerbate salinity, and hence further degrade land resources.

Other non-conventional sources of water are produced such as wastewater, treated waste water, reused treated waste water, and desalinated water; these are reused together with agricultural drainage water.

5.3. MAJOR CAUSES OF SALINITY

Kuwait is a desert country with an average temperature of 45ºC during the long hot dry summer season and falling to below 4ºC in winter. The annual precipitation is very low and ranges between 106 and 134 mm [5.6]. The extremely arid climate and low annual precipitation leads to low soil water content and high evaporation that eventually increases soil salinity. Primary salinization occurs in soils naturally rich in soluble salts, and is prevalent in areas with a shallow saline groundwater table. Secondary salinization occurs when low quality brackish or saline irrigation water is used without adopting adequate leaching and drainage measures in the irrigation system. Deforestation and overgrazing also contribute greatly to soil salinity [5.8].Waterlogging is observed upon leaching with inadequate drainage systems. Thus excess leaching with insufficient drainage, insufficient application of water, poor land levelling, inappropriate crop rotation systems, chemical contamination from excessive use of fertilizers, dry season fallow practices with a shallow water table, misuse of heavy machinery resulting in soil compaction and inadequate drainage, and inefficient irrigation all significantly increase soil salinity.

5.4. EFFECT OF SALINITY ON CROP PRODUCTION

Salt-affected soils are characterized by the formation of salt crusts on the soil surface and are classified into saline, saline-sodic and sodic soils based on the content and concentration of the

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salt present [5.8]. Increased soil salinity reduces the availability of water and nutrients in the root zone of plants. Plants undergo water stress, oxidative stress, ion toxicity, genotoxicity, hormonal imbalances, membrane disorganization, reduced cell expansion and division, all of which significantly reduce overall growth and productivity. Plants exhibit poor growth patterns with delayed germination and foliar damage. In addition, salinity affects water quality, causing serious social, economic and environmental issues. Bio-saline agriculture has gained momentum in this scenario, where crops tolerant of salinity are cultivated in the salt-affected areas through improved soil and water management techniques.

Several studies have been conducted in Kuwait to ascertain the effects of brackish water irrigation on plant growth and productivity. Various crop genotypes have been classified as tolerant, moderately tolerant, semi-sensitive and sensitive based on their yield potential in soil with different levels of electrical conductivity and exchangeable sodium percentage. The performance evaluation of mutant barley genotypes under a brackish water irrigation system has identified number of salt-tolerant varieties for cultivation in Kuwait’s harsh environmental conditions [5.9]. Introduction of a farming approach with improved soil, water and nutrient management practices in the crop production system could significantly reduce soil salinization and sodification.

5.5. RANGE OF CROPS GROWN BY FARMERS IN SALT-AFFECTED AREAS Kuwait’s arable land is characterized by sandy soil with low water retention capacity, poor organic matter content and low nutrient content. All these factors have negative impacts on the healthy growth of plants. Out of the total harvested irrigated cropped area of 8055 hectares, wheat, barley, potatoes, vegetables, dates, and other annual and perennial crops constitute about 290, 1263, 760, 3660, 390, 1589 and 103 hectares respectively [5.6]. About 45% of the agricultural land is devoted to vegetable production - mainly tomatoes, eggplants, cucumbers and sweet peppers - and 19% is used to cultivate cereals such as barley and wheat. Date palm trees are the most important fruit trees grown, and occupy about 20% of the cultivated land. In 2003, agricultural production included 207 000 tons of vegetables, 18 000 tons of fruits and about 3300 tons of cereals [5.10].

5.6. MEASURES IMPLEMENTED TO ADDRESS SALINITY

Recently several projects have been initiated as coordinated research projects and technical cooperation programmes in cooperation with the International Atomic Energy Agency (IAEA) aimed at the enhancement of use of salt affected soils and saline water. This will be achieved by the introduction of alternative sources of irrigation water, such as treated wastewater and brackish water, optimization of water and fertilizer use efficiency and development of genotypes with desirable traits through mutation breeding.

To manage the salinity problem, research needs to be undertaken to determine the best practices of soil reclamation and management, such as the best mix of plants and possibly sub-surface drainage to achieve salinity control. Al-Menaie [5.11] suggested the following as pre-requisites for research on salt-affected soils in Kuwait:

45 (a) Identification, mapping and characterization of salt-affected soils.

(b) Identification of the causes and sources of salinity.

(c) Corrective measures.

Several corrective measures such as physical methods (sanding, subsoiling, scraping, land levelling), biological methods (organic manure application, blue-green algae, saline agriculture, crop rotation, mulching), chemical methods (amendment, soil conditioning, mineral fertilizer) and hydraulic methods (leaching, irrigation, drainage, safe disposal of saline waters) are advocated to reclaim salt affected soils by removing excess salts from the root zone [5.12]. Continuous cropping assists the sustainability of crop production in reclaimed land by maintaining the organic carbon content of the soil. Incorporation of legumes in the cropping system with minimal tillage is a sustainable approach to improving physical soil conditions and crop yield, by increasing nitrogen content in the soil, pore space, air holding capacity, organic matter content and microbial activity. Thus, an integrated approach of physical, chemical, and biological reclamation approaches is necessary to turn barren salt-affected areas into productive land.

5.7. MAJOR GAPS TO FURTHER IMPROVEMENTS The major gaps are:

(a) Insufficient desalinated freshwater for agricultural purposes and poor quality groundwater.

(b) Nuclear-isotopic techniques not introduced in soil-water-crop management systems and plant breeding in Kuwait.

(c) Unavailability of suitable equipment for mutation breeding and soil and water management using nuclear-isotopic techniques.

(d) Lack of qualified staff in mutation breeding, soil and water management using nuclear-isotopic techniques and crop simulation models.

(e) Lack of local crop genotypes with high water use efficiency, crop water productivity, and improved yield adaptable to Kuwait’s environmental conditions.

5.8. THE USE OF NUCLEAR AND ISOTOPIC TECHNIQUES

No nuclear or isotopic techniques are currently in use in Kuwait. However, the use of ¹⁵N for the estimation of nitrogen use efficiency as well as the Cosmic Ray Neutron Sensor for soil moisture estimation will be incorporated in the near future. These techniques will help determine irrigation scheduling and fertilizer precision application.

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REFERENCES TO CHAPTER 5

[5.1] FOOD AND AGRICULTURE ORGANISATION OF THE UNITED NATIONS, Irrigation in the Near East Region in figures. FAO Water Report No. 9. (1997), Rome.

[5.2] SHADID, S. A., OMAR, S. A. S., GREALISH, G., KING, P., EL-GAWAD, M. A., AL-MESABAHI, K., Salinization as an early warning of land degradation in Kuwait. Problems of Desert Development 5 (1998) 8.

[5.3] HAMDALLA, G., An overview of the salinity status of the near east region. In:

Proceedings of regional workshop on management of salt affected soils in the Arab gulf states. Abu Dhabi, United Arab Emirates, 29 Oct–2 Nov, 1995.

Published by Food and Agriculture Organization of the United Nations (1997) Cairo.

[5.4] ERGUN, H.N., Reconnaissance Soil Survey. FAO report No. FAO/KU/TF 17 submitted to Kuwait Government (1969) pp. 1.

[5.5] OMAR, S. A. S., MISAK, R., KING P., SHAHID, S. A., ABO-RIZG, H., GREALISH, G., ROY, W., Mapping the vegetation of Kuwait through reconnaissance soil survey. Journal of Arid Environments 48 (2001) 341.

[5.6] FOOD AND AGRICULTURE ORGANISATION OF THE UNITED NATIONS, Irrigation in the Middle East Region in figures. Edited by K.

Frenken. FAO Water Report No. 34 (2009), Rome.

[5.7] AL-SULAIMI, J., VISWANATHAN, M. N., NAJI, M., SUMAIT, A., Impact of irrigation on brackish groundwater lenses in northern Kuwait. Agric. Water Manage. 31 (1996) 75.

[5.8] AL-HIBA, M., Improvement of Irrigation and Drainage Systems for Soil Salinity Control in the Arab Region. In: Proceedings of regional workshop on management of salt affected soils in the Arab Gulf States. Abu Dhabi, United Arab Emirates, 29 Oct–2 Nov, 1995. Food and Agriculture Organization of the United Nations (1997), Rome.

[5.9] AL-MENAIE, H. S., Integrated utilization of cereal mutant varieties in crop and/or livestock production systems. Kuwait Institute of Scientific Research, Report No. 11937 (2013), Kuwait.

[5.10] PUBLIC AUTHORITY OF AGRICULTURE AFFAIRS AND FISH RESOURCES (PAAFR), Communication to the Permanent Representative of the State of Kuwait to the Food and Agriculture Organization of the United Nations (2006), Kuwait.

[5.11] AL-MENAIE, H. S., Matching soil, water, and genotype for barley cultivation in Kuwait. PhD thesis (2003), The University of Reading, UK.

[5.12] FOOD AND AGRICULTURE ORGANISATION OF THE UNITED NATIONS, Management of Irrigation Induced Salt Affected Soils. Joint brochure by the Centre virtuel de l’eau agricole et ses usages (CISEAU), IPTRID, and AGLL, FAO (2005), prepared in collaboration with Rhodri P.

Thomas (concept) and Simone Morini (design). at ftp://ftp.fao.org/agl/agll/docs/salinity_brochure_eng.pdf.

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