A field experiment was carried out on saline soil (loamy sand soil) at Gelbana Village, El-Tina Plain, NorthWestern Sinai Peninsula , Egypt during two successive growing summer seasons of 2011 and 2012 to study the influence of potassium fertilization on the productivity of maize (Zea mays L. , cv. Trible hybrid 310) and yield component. The maize was grown on newly reclaimed saline soil of Egypt under different levels of irrigation water. The used irrigation water resource was El-Salam Canal. Potassium fertilization was applied as soil application at rates of 0 , 24 , 36 and 48 kg K2O / fed. and as foliar application at rates of 0 , 1 , 2 and 4 % K2O, equal to 0, 4 , 8 and 16 kg K2O/ fed., respectively which dissolved in 400 liter water of irrigation and sprayed. The used K fertilizer was K2SO4 (48 % K2O). Each rate of added K as soil application and foliar application was added on two equal doses after 30 and 65 days from sowing. Surface irrigation system was used , where the soil was irrigated at three levels of water requirement (WR) of maize plant under saline soil conditions. These levels were 50 , 75 and 100 % of WR , which equal 4250 m 3 / fed. The experiment was carried out in split design with three replicates. The obtained data show that , K fertilization with either of soil or foliar application resulted in a significant increase of the measured growth parameters .i.e. stover and yield (ton / fed.) , grains weight (g / plant) , ears weight (g / plant) , weight of 100 grains (g) and biological yield (ton / fed.). According to the mean values of RC (%) , the grains yield was more than stover yield with foliar application , where the stover yield was more than grains yield with soil application. The increases in these parameters were increased with increasing K rate. At the same irrigation level , the yields of stover and grains produced from each one m 3 of the added water was increased with the increase rate of added K as soil or foliar application. Under different treatments of K fertilization, the grain content (%) of N , P , K and protein were increased significantly and its become more significant with the increase of added irrigation water. Maize grains contents (mg / kg) of Fe , Mn and Zn were increased significantly with the increase of added K fertilization for both soil and foliar applications. Except K, the contents of the determined macro and micronutrients resulted from the treatments of soil application, were higher than those associated the treatments of foliar application. Under saline soil conditions, the best treatment was soil application of K fertilization at rate of 48 kg K2O / fed. with irrigation at 100 % WR. The important conclusion which may be extract from the obtained data is potassium fertilization increased irrigation water use economy. The best value of water economy were with 48 kg K2O / fed. as soil application and 4 % K2O as foliar application at 50 % WR .
