The Jewish settlers returning to the Holy Land (then part of the British Mandate) in 1870, after 2000 years of exile, were firmly decided to redeem this land, to cultivate it and to return the Jewish people to agriculture.
Reality was quite different. The centuries had ravaged the land, leaving it damaged and dry. The settlers soon discovered that the Holy Land was located at the edge of the desert, that rainfall was limited to five months in the winter (November to March), and that water resources were scarce. Rainfed agriculture was hardly viable due to the small size of the plots each farmer cultivated. And most of these settlers had no tradition of agriculture.
That, in fact, made it easier for them to start from scratch and learn to implement modern agricultural methods, in which profits could be achieved even from small plots. An important ingredient of such modern agriculture was - and is - irrigation. Two generations of farmers have put tremendous effort into learning the secrets of irrigation. After the establishment of the State of Israel in 1948, more land became available and many agricultural settlements were founded by new Jewish immigrants arriving from 100 nations around the world. The main limiting factor of growth in agricultural production was water. The existing wasteful surface (gravitational) irrigation techniques were not compatible with the necessity of obtaining the most from any unit of land. In an extensive array of field trials and demonstration plots, it was proven that pressurized irrigation systems could save as much as half the amount of water compared to surface irrigation. It also increased yields and improved quality in principal crops, such as cotton, potatoes,
tomatoes, citrus and bananas.
Further improvement in water efficiency was achieved with drip irrigation. The idea was initiated in the early 1930s when the late Simcha Blass, a well-known hydrologist, noticed the extraordinary growth and development of a grapefruit tree planted over a leaking water supply pipe. Only 30 years later, in the early 1960s, when plastic tubes and accessories became available, did he succeed in accomplishing his vision to supply water directly and accurately to the root-zone according to crop demand. The implementation of the new technique, drip irrigation, triggered further advancements like chemigation, the injection of nutrients and pesticides into the irrigation system for direct introdliction into the root-zone.
Drip irrigation decreased weed expansion as well as leaf diseases, and enabled farmers to use brackish water for irrigation of agricultural crops. Israel has disseminated the idea of drip irrigation to many countries all over the world and set a new standard in accuracy and efficiency of water and nutrients supply in accordance with crop demand.
In orchards, new agrotechniques have significantly changed harvest results. Increased tree density is accompanied by reduced tree size to facilitate mechanical pruning and make harvesting cheaper. The amount of water for irrigation is determined by combined climatic, soil moisture and physiological parameters. Timing of application of water is directed by measurements of the rate of fruit growth. There is wide-scale use of pressure and flow regulated and compensated drippers and
microsprinklers to overcome topographic difficulties and ensure uniform water distribution. Many orchards which in the past were planted in heavy compact soil suffered from insufficient aeration of the soil and decline over time. Today, trenches filled with aggregates (ruff and basalt gravel), irrigated and fertilized in greenhouse regime, have brought about a doubling of yields and better resistance to harsh climate conditions.
In field crops, especially cotton, another physiological parameter is used for optimization of water applications. Timing of application is determined by measuring water tension in the plant by pressure chamber. Leaves are cut at midday and water tension measured, which allows farmers to decide whether to irrigate or not. Using this method, tomatoes may be canned with an optimal balance between yield and quality measured in Bricks degree (relation between sugar and acidity indicating ripeness). In addition, although significant portions of the Israeli water reserve are brackish, in the Negev Desert this drawback has been turned to advantage since controlled application of brackish water changes the proportion of sugar to acids in tomatoes and melons, thereby improving the quality of the produce.
In greenhouses the integrated computerized systems controlling irrigation, fertilization, temperature, humidity and aeration are gaining momentum. Different sensors for salinity, pH level and the major nutrient concentrations determine automatically timing and rate of water application, as well as the mixing of nutrients and neutralizing of bi-carbonates in irrigation water to eliminate lime precipitation in the laterals and the emitters. Ultra-low-rate irrigation, with application rates lower than 1 mm per hour, changes water distribution in the bed pattern, the lateral movement is much better and less water is lost.
With the support of research and extension, innovations can be disseminated promptly all over the country. Developers and producers send feedback to researchers quickly. This free flow of information is one of the main motivating factors for the use of the state-of-the- art instrumentation by farmers. As a by-product of advanced agriculture, factories producing irrigation equipment have been established, mainly in agricultural settlements (kibbutz and moshav), run by farmers and ex-farmers. Among the innovative devices developed are automatic valves, fertilizer injectors, compensated dripper laterals and mini-sprinklers, irrigation controllers and computers.
Looking around, more than 90% of the irrigated land in the world is still irrigated by inefficient surface techniques. Surface irrigation has other drawbacks in addition to low efficiency: the high cost of land levelling and canal construction, maintenance difficulties, erosion and clogging of canals by weeds. Estimated average worldwide water use efficiency is about 30%, while in well-managed pressurized irrigation systems it amounts to 80% and higher. With drip irrigation, efficiency may be 90%. In Israel all irrigated land is under pressurized irrigation in order to ensure high efficiency of water use.
Scarcity of water is not the problem of arid lands alone. Population growth and climatic change has meant that more and more nations are prone to water shortages. Therefore, the notion of efficient water use has worldwide significance.
Since the late 1950s, Israel has shared its experience inefficient water use with other nations through its international cooperation program. Irrigation and water experts have been involved in planning, building and management of water supply and irrigation projects in many parts of the developing world. The know-how accumulated here and abroad is being shared with cooperating countries through training seminars and workshops both in Israel and overseas. The message delivered through these activities is that water is a precious and limited resource. It has to be conserved and handled carefully for the benefit of mankind. The technology for this end has been developed and is at our disposal. Awareness and dedication, as well as education and practice, can ensure the efficient use of water anytime and anywhere. The courses and seminars in Israel are all geared towards the practical aspects of irrigation and rational water use. Years of training in irrigation have crystallized the circle of dedicated messengers of efficient water use, all graduates of these courses spread out over five continents.
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One of the highlights of the international cooperation is the tri-annual Agritech exhibition, where the achievements and latest innovations of Israel's advanced agriculture and dynamic agricultural industry are there for local farmers and visitors from abroad to see.
The upcoming Agritech Spring '96 - May 12-16, 1996 - will be the biggest and most spectacular of all the exhibitions held in Israel. The
mood of peace in the Middle East is bound to attract many visitors from neighbouring countries, in addition to visitors from other parts of the world.
One of the main topics of this exhibition will be water and irrigation. In this framework, the 7th International Conference on Water and Irrigation will take place. As in the past, participants will be exposed to some of the latest innovative applications in agriculture: ultra-low-rate irrigation, improved produce quality by irrigation with brackish water, doubling yields in plantation using greenhouse technologies, and more. Professional tours will complement the conference and the participants can witness the applications first hand. The exhibition and the conference will be a good opportunity for graduates of courses and seminars on irrigation to be updated in the latest developments in water and irrigation, to meet each other and to share experience. Business can be combined with pleasure. Springtime in Israel means flowers, warm weather and a lot to see.