بررسی اثر متقابل شوری و عناصر غذایی ‭N ,P ‬و ‭K ‬بر عملکرد لاین امیدبخش مقاوم به شوری گندم

Wheat yield in arid and semiarid regions of the world simultaneitly suffers from the high soluble salt concentrations as well as low availability of macro nutrients. Three experiments were conducted in Sadooq Salinity Research Field, located in Yazd, to study the effect of salinity stress on the nitrogen, phosphorous and potassium fertilizer requirement of wheat, during 2002-2006. Each experiment had three salinity levels (ECiw=2, 7 and 14 ds/m) as the main plot. Main plots in the first experiment were splitted into 5 urea application rates of 0, 100, 200, 300 and 400 Kg urea/ha. Second experiment had four subplots receiving 0, 100, 200 and 300 Kg triple super phosphate per hectar. Subplots in the third experiment received 0, 100,200 and ~OO Kg potassium sulphate per hectar. The results showed that nitrogen and phosphorous fertilizers are necessary to obtain maximum yied, while potassium fertilizer did not improve the grain yield. This is concluded from the significant positive effect of nitrogen and potassium fertilizers on grain yield in most years of the experiment. Also salinity stress decreased the nitrogen, phosphorous and potassium requirement of wheat and the negative effect of salinity did not alleviate by extra application of fertilizers. In general, it is concluded that when salinity is the dominant limiting factor, applying fertilizers is relatively ineffective and decreasing soil salinity is recommended, while if the soil fertilllity is the dominant limiting factor increasing soil fertility by chemical fertilizers is recommended.