THE RELATIONSHIP OF THE YIELD OF IRRIGATED BARLEY TO SOIL SALINITY AS MEASURED BY SEVERAL METHODS

A field study was conducted to measure the effect of soil salinity on barley grown under irrigated conditions in Alberta. Salinity was measured by the saturated paste extract, 1:2 soil-to-water extract, vertical probe and horizontal surface array methods. Correlation coefficients were determined between salinity measurements and the yield of barley to establish the suitability of these methods for predicting the growth of barley. Nineteen fields over 2 yr were monitored and soil salinity and the yield of barley were determined at a number of sites in each field. All methods of measuring salinity were significantly correlated (P = 0.01) with the yield of barley. At an EC of 7.8, yields of barley were reduced by 50%. Sodium concentration and sodium adsorption ratio were closely correlated with yield of barley and with saturated-paste-extract salinity. Soil moisture and pH were not as effective as salinity and sodium measurements in predicting the yield of barley. The saturated-paste-extract salinity was more closely correlated with the 1:2 soil-to-water extract than with the vertical probe or the horizontal surface array. The latter three methods were effective for rapid determination of the yield reductions which would occur on saline soils. No difference in tolerance to salinity was found between Klages (two-row) and Galt (six-row) cultivars of barley. Key words: Salinity tolerance of barley, methods of measuring salinity, vertical probe EC, horizontal array EC, saturated paste EC, 1:2 soil-to-water extract EC