Irrigating with Saline Water
Kirsten Kaplan
Agriculture in Israel
• In 2010, 42% of Israel’s exports ($2.13 billion) were
agricultural
• 60% of fresh vegetable exports come from Arava region (in Negev desert)
• In 2011 1,189 million cubic meters (mcm) of water
was used in agricultural production
• 680 mcm was recycled and brackish water
• Water is a major issue in Israel and the Middle East, so
increasing the use of marginal water is important
• In the Arava region (in Negev desert): drip irrigation,
greenhouses, irrigation with saline water
Challenges for Irrigation with Saline Water
• Irrigating with saline water requires a unique approach
• Salty water makes it harder for plants to take in water
– Salt gradient between water and intracellular fluid is reduced
– If saline water is sprayed directly on leaves, can cause leaf
damage
– If water is too salty, osmosis can actually be reversed and water
will be pulled out from plant cells
• Plant then looses moisture and enters a state of extreme stress
• To effectively irrigate with brackish water, Israel turned to
grafting
– Use rootstocks that are better adapted to regulating the
transport of excess salt ions
– With certain grafted roots, can get an 80% increase in yield
Grafting
• Grafting essentially involves taking the scion (bud or
shoot) of one plant and attaching it to the rootstock
of another
• For tomatoes, this process involves
growing two different varieties of
tomatoes, cutting the stem of both
plants when each has about 2 sets of
leaves, and attaching the scion and
rootstock of the two plants together
using a silicon clip
– Takes about 5 weeks from planting the
seeds until plants are successfully grafted
and ready to be moved to the field
Grafted tomato plant
Success with Saline Irrigation
• Israel developed the Desert Sweet tomato, which is
irrigated with saline water
– This tomato is actually sweeter than other tomatoes!
– How does that work? The salt changes the osmolarity of the water,
which stresses the plant/plant cells causing them to produce more
sugars
– Israel has achieved similar results with sweet peppers and melons
• Negev farmers have been able to time their peak
growing seasons between typical peak growing
seasons
– Allows them to export and sell fresh produce at a higher price,
especially in Europe
– The higher price is important to compensate for higher water
prices in Israel/the Negev and the increased distance between
the site of production and the market
Works Cited
• Bringing water to the desert. Jewish National Fund. http://www.jnf.org/work-we-do/ourprojects/research-development/bringing-water-to-the-desert.html
• Brown, A. S. 2011, April 27. Hidden water holds the key to a changing desert. Inside
Science. http://www.insidescience.org/content/hidden-water-holds-key-changingdesert/1234
• Byczynski, L. 2011, March. Grafted tomatoes: worth the trouble? Growing for Market.
http://www.growingformarket.com/articles/Grafted-Tomatoes
• Cross, N. 2001. Using saline water for irrigation. Primary Industries Agriculture.
http://www.dpi.nsw.gov.au/agriculture/resources/soils/salinity/crops/saline-irrigation
• Edelstein, M. and M. Ben-Hur. 2011. Grafting to prevent contaminants’ penetration into
vegetable plants. Israel Agriculture.
http://www.israelagri.com/?CategoryID=396&ArticleID=627
• Estan, M. T., Martinez-Rodriguez, M. M., Perez-Alfocea, F., Flowers, T. J. and M. C. Bolarin.
2005. Grafting raises the salt tolerance of tomato through limiting the transport of
sodium and chloride to the shoot. Journal of Experimental Botany 56(412): 703-712.
• Garrett, A. 2011. Grafting vegetables- is it worth the trouble? Many growers say yes.
Small Farms, Oregon State University.
http://smallfarms.oregonstate.edu/sfn/su11graftveg
• Moisa, S. (ed.). Israel’s Agriculture. The Israel Export and International Cooperation
Institute. http://www.moag.gov.il/agri/files/Israel's_Agriculture_Booklet.pdf