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Abstract

A field experiment was organized on sandy soil (TypicTorriorthent) at a private vine yard (Agrofarms) at South El-Tahrer Province, El-Behiera Governorate, Egypt during 2015/2016, to establish the adequate ranges for some nutrients (N, P, K, Ca, Mg and Cl) through DRIS method under different K-fertilizers combination ratios. Fertigation was applied at the following twelve mixing ratios of potassium chloride (60 % K2O) K-KCl, potassium nitrate (46 % K2O) K-KNO3 and potassium sulfate (50 % K2O) K-K2SO4: (100 / 0 / 0), (75 / 25 / 0), (50 / 50 / 0), (25 / 75 / 0), (0 / 100 / 0), (0 / 75 / 25), (0 / 50 / 50), (0 / 25 / 75), (0 / 0 / 100), (25 / 0 / 75), (50 / 0 / 50) and (75 / 0 / 25) relative to 100 that equal to the total K requirement during growth stage (160 unit). The results showed that the lowest Nutrient Balance Index (NBI) was listed from blending treatments 0 % KCl + 50 % KNO3 + 50 % K2SO4, 25 % KCl + 75 % KNO3 + 0 % K2SO4, 0 % KCl + 25 % KNO3 + 75 % K2SO4 and 50 % KCl + 50 % KNO3 + 0 % K2SO4 were attained 25.90, 30.23, 30.56 and 33.13, respectively; these treatments achieved high quantity of grape yield which were 12.5, 11.0, 9.66 and 9.54 ton fed-1, respectively. The sufficient ranges for N, P, K, Ca, Mg and Cl were 0.97 to 0.86, 0.27 to 0.20, 2.81 to 2.11, 2.81 to 2.11, 1.05 to 0.77, 0.69 to 0.53 and 0.66 to 0.34 %, respectively. Whereas the deficient values of N, P, K, Ca, Mg and Cl when the concentration of these nutrients are less than 0.80, 0.16, 1.75, 0.64, 0.45 and 0.19 %, respectively.