The technical capability to pump groundwater from the Israeli Coastal Aquifer was met at the end of the 19th century, and triggered a bloom in irrigated agriculture over the Coastal Plain of Israel. This paper deals with important feedbacks of irrigation on the aquifer. Irrigation does not always increase aquifer recharge. Under many citrus orchards on Hamra soils (Mediterranean red sandy-loam to loamy sand) groundwater recharge is smaller than it would have been under bare soils with no irrigation, whereas under winter crops (e.g. potato, strawberry) or deciduous groves (e.g. persimmon) irrigation increases groundwater recharge. Groundwater salinization is high under the irrigated naturally-cracking clayey soils (vertisols) due to flushing of salts that accumulated in the unsaturated zone for centuries prior to irrigation and intensive cultivation. This phenomena does not occur under Hamra soils and groundwater salinization is minor to moderate. On the other hand, contamination of groundwater of the coastal aquifer by nitrate is typical under irrigated Hamra soils and is a small problem under vertisols, due to high denitrification rates in irrigated clays.
The technical capability to pump groundwater from the Israeli Coastal Aquifer was met at the end of the 19th century, and triggered a bloom in irrigated agriculture over the Coastal Plain of Israel. This paper deals with important feedbacks of irrigation on the aquifer. Irrigation does not always increase aquifer recharge. Under many citrus orchards on Hamra soils (Mediterranean red sandy-loam to loamy sand) groundwater recharge is smaller than it would have been under bare soils with no irrigation, whereas under winter crops (e.g. potato, strawberry) or deciduous groves (e.g. persimmon) irrigation increases groundwater recharge. Groundwater salinization is high under the irrigated naturally-cracking clayey soils (vertisols) due to flushing of salts that accumulated in the unsaturated zone for centuries prior to irrigation and intensive cultivation. This phenomena does not occur under Hamra soils and groundwater salinization is minor to moderate. On the other hand, contamination of groundwater of the coastal aquifer by nitrate is typical under irrigated Hamra soils and is a small problem under vertisols, due to high denitrification rates in irrigated clays.