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EFFECT OF SOME AMINO ACIDS ON THE PHYSIOLOGICAL CHARACTERISTICS OF
                       MAIZE PLANT UNDER SOIL SALT STRESS CONDITIONS IN EGYPT AND TUNISIA
              ground, then sieved through (2 mm) sieve. Plant samples of maize
              crop were collected at milk stage “120 DAS”.


                  2.2. Analytical methods.


                  2.2.1. Water analysis

                  Hydrogen ions activity (pH value), electrical conductivity (EC),
              total dissolved salts (TDS) calculated from EC values and total al-

              kalinity (mg.l-1) were determined according to APHA (2012); so-

              dium adsorption ratio (SAR, meq.l-1) (Suarez (1981). Na+ and K+
              ware determined by flame photometer. Ca++ and Mg++, by titrimet-
              ric method using (EDTA). Soluble anions (Cl-, HCO3-, CO3= and

              SO4=) were analyzed using ion chromatography (IC) model DX-

              2500. Water samples analysis were carried out according to stan-
              dard methods for examination of water (APHA, 2012). Guidelines
              to emphasize the long-term influence of water irrigation quality were

              adopted according to FAO (1985).


                  2.2.2. Soil analysis

                  Particle size distribution was determined using pipette method
              as described by Richards (1954). Soil extract (1: 2.5) was prepared.

              Organic matter (O.M.) %, using the method of by Jackson (1973).
              Calcium carbonate (CaCo3) %, using the Collin’s Calcimeter meth-

              od (Wright,  1939). Available  macronutrients  [phosphorus (P) and
              potassium (K)] using the atomic absorption spectrophotometer (Ber-

              kin- Elemer 2380) were determined as described by Soltanpour and
              Schwab (1977) and Lindsay and Norvel (1978). Total nitrogen (N)

              was determined by the modified macro- kjeldahl technique as out-
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