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<br /> <br />.'. <br /> <br />~.. <br /> <br />, 00b298 <br /> <br />\ <br /> <br />\ ' <br /> <br />~ <br />;;; <br />~ <br />i <br />, <br />. <br /> <br />,~lIlrrlgation waters contain dissolved salts of varying concentrations. Above, Agricul8 <br />tural drainage feeds directly Into the Saltor Sea,..maklng It more saline than an ocean. <br />Right, Salton Sea: Is an Important stopover for migratory birds on the P-acific Flyway. <br /> <br />, r <br /> <br />Soil salinity poses challenges <br />for sustainable agriculture and wildlife <br /> <br />John Leley <br /> <br />If soil becomes too saline, crop <br />productivity falls. In California, the <br />Imperial Valley and western San <br />Joaquin Valley are major areas of <br />concern where salinity can harm <br />agricultural productivity. The Im- <br />perial Valley has achieved salt <br />balance by discharging salty <br />drainage water Into the Salton <br />Sea, but this practice threatens <br />fish and possibly birds. Without <br />an avenue to remove salts from <br />the western San Joaquin Valley, <br />long-term agrIcultural productivity <br />'s jeopardized unless an in-valley <br />sink, such as evaporation ponds, <br />can be used to accumulate the <br /> <br />salts. Howe.ver, high selenium <br />concentrations in drainage-water <br />evaporation ponds can be hazard- <br />ous to birds. The future of agricul- <br />ture and wildlife in both valleys <br />canbe enhanced by cooperative, <br />innovative approaches between <br />government, growers and environ- <br />mental advocates. For example, <br />water allocated tor agriculture can <br />be used to construct highly pro- <br />ductive "compensation habitats," <br />which can attract high concentra- <br />tions of nesting birds and offset <br />negative impacts to Wildlife at the <br />Salton Sea and West Side evapo- <br />ration ponds. <br /> <br />History has recorded several major <br />occurrences ,of salinity and its efw <br />feet5 on society, but the earliest and <br />perhaps most seriolls occurred during <br />2400-1700 a.c. in ancient Meso- <br />potamia, now southern lraq (Jacobsen <br />and Adams 1958). Irrigation projects <br />were developed to deliver water for. <br />agricultural production; copiolls quan~ <br />tities of water were-available, leading <br />to increased seepage, flooding, over- <br />irrigation and a consequent rise in the <br />water table. Initially, only a few fields <br />wer~ affe.cted, but an increase in the <br />saline levels of fields \'.:as recorded be~ <br />tween 2100 and 1800 a.c. The B,)by- <br />Ionian story of Atrahasis e\'en men~ <br />tions the "turning white of the fields" <br /> <br />CALIFORNIA AGRICULTURE. MARCH-APRIL 2000 43 <br />