Lack of water is a major constraint in Israeli agriculture. Less than half of the arable land is irrigable due to the shortage of water. Over 500 km, from north to south, Israel's annual rainfall ranges from 800 mm to 25 mm. The rainy season lasts from October to April, with no rain during the hot summer.

Use of Land and Water in Agricultural Production:

Since the establishment of the State of Israel has increased in 1948, agricultural output has increased twelve-fold, while water use in agriculture has increased only three-fold. The output value in fixed prices has tripled per land unit and increased five-fold per water unit.

Water Resources:
Although most of the water resources are in the north and center, agriculture is being developed in the arid south and east. This reality has necessitated construction of an integrated water supply system, which delivers water from the north to the south. The only significant surface freshwater reservoir is the Sea of Galilee, from which an annual average of 400 million m3 is pumped to the south. The total annual water potential is roughly 2 billion m3.Due to over pumping and frequent droughts, the actual available annual water volume is 1.5 to 1.7 billion m3.

The annual water allocation for agriculture is about one billion m3, about one half of which is recycled and brackish water. Water is regarded as a national asset and is protected by law. Users receive their annual allocation from the Water Commission. The entire water supply is measured and payment calculated according to consumption and water quality.

Urbon users pay much higher fees for water than farmers, including a water reclamation levy. Farmers pay differential prices for potable water. The first 60% of the allocation costs 20 cents per m3, 60% to 80% costs 25 cents, and 80% to 100% costs 30 cents per m3. This incremental price policy encourages water saving.

Water scarcity and price policy necessitate the use of marginal water, such as brackish and reclaimed water. Brackish water is used for irrigation of salinity tolerant crops like cotton. In several crops, such as tomatoes and melons, brackish water improves produce quality although lower yields are achieved. The use of reclaimed water for irrigation of edible crops requires a high level of purification.
For that purpose, a unique technology Soil Aquifer Treatment (SAT) is now being applied in the densely populated Dan region. After tertiary purification, the water percolates through sand layers, which serve as a biological filter, into the aquifer. From there it is pumped at nearly potable quality and can be used for unrestricted irrigation.

Irrigation Technology :

Since the early 1950s, intensive efforts have been invested in irrigation research. It was clearly shown that water use is much more efficient in pressurized irrigation than in surface irrigation. An irrigation equipment industry was established, mainly in kibbutzim, which developed innovative technologies and accessories such as drip irrigation (surface and subsurface), automatic valves and controllers, media and automatic filtration, low-discharge sprayers and mini-sprinklers, compensated drippers, and sprinklers.

Fertigation is routine in most of the irrigated areas. Fertilizer producers have developed highly soluble and liquid fertilizers which are compatible with this technology.