Assessment of different soil to water ratios (1:1, 1:2.5, 1:5) in soil salinity studies

Soil salinity is one of the limiting factors of agricultural productivity. It is essential to determine the soil salinity in a reliable and yet relatively easy method. This experimental study was carried out to assess the possibilities of measuring electrical conductivity as well as ion concentrations in the extracts of different soil to water ratios, (1:1, 1:2.5, 1:5), and to compare them with those measured in saturated paste extract. Sandy, loamy, and clay textured soils were artificially salinized for one month by capillarity with different saline water of 0.02 (de-ionized water), 0. 4 (tap water), 2, 4, 8 and 16 dS/m. The saline waters were prepared by adding various amounts of NaCl, KCl, and CaCl2 into tap water for each level of salinity to obtain desired salinity level. Having measured electrical conductivity, the extracts were analyzed for Na+, K+, Ca2+, Mg2+, Cl−, CO32−, and HCO3−. The results showed that highly significant correlation exists between values measured in saturated paste extracts and in extracts of different soil to water ratios for electrical conductivity and ion concentrations. Based on the results obtained, it was concluded that extracts of (1:1), (1:2.5) or (1:5) soil to water ratios can be used to estimate saturated paste electrical conductivity and ion concentrations of soils.