COMPARISON OF 1:1 AND 1:2 SUSPENSIONS AND EXTRACTS WITH THE SATURATION EXTRACT IN ESTIMATING SALINITY IN SASKATCHEWAN SOILS

Abstract

Electrical conductivity of saturation extracts was related to that of 1:1 and 1:2 (soil:H 2 O) suspensions and extracts for a wide range of Saskatchewan soils. The conductivity of 1:1 extracts was 1.75 times greater than for 1:1 suspensions and the conductivity of 1:2 extracts was 1.38 times greater than that of 1:1 suspensions. The conductivity of the saturation extract was closely related to all of 1:1 extract or suspension; 1:2 extract or suspension (r = 0.96–0.98). The regression coefficient relating the conductivity of 1:1 and 1:2 extracts and suspensions to that of the saturated paste extract decreased in going from coarse to medium to fine soil textures. The concentrations of Na + , Ca 2+ + Mg 2+ and Cl − in 1:1 and 1:2 (soil:H 2 O) extracts were highly correlated with the amounts in the saturation extract (r = 0.93 to 0.99). Key words: Soil salinity, 1:1 and 1:2 suspension and extract, saturated paste