Soil Salinity Assessment Using Saturated Paste and Mass Soil:Water 1:1 and 1:5 Ratios Extracts

Abstract

Soil salinization is directly related to the quantity and quality of food production, and often, to increased energy demands for high-quality irrigation water. Reliable monitoring of soil salinity based on a less laborious method than the soil saturated paste (SP) extract methodology is required. In the present study, an attempt is made to relate the electrical conductivity (EC) of the soil saturated paste (SP) extract (ECe) with the EC determined in the 1:1 and 1:5 soil over water mass ratios, (soil:water) extracts (EC1:1 and EC1:5). ECe, EC1:1, and EC1:5 values were obtained for 198 soil samples from five different locations in Greece. The results have shown that strong linear relationships exist between the ECe and the EC1:1 and EC1:5 values (R2 > 0.93), and that the slopes of these linear relationships decreased from coarse to fine soil types. For 123 soil samples, the concentrations of Κ+, Νa+, Ca2+, Mg2+, and Cl− were also determined in the extracts of the three applied methodologies. Ion concentrations in the 1:1 and 1:5 extracts were highly correlated with the respective ion concentrations in the SP extracts. These findings strongly suggest that EC1:1 and EC1:5 values can be safely used for the estimation of ECe.

Comparison of Soil EC Values from Methods Based on 1:1 and 1:5 Soil to Water Ratios and ECe from Saturated Paste Extract Based Method

“…These data confirm the existence of a strong linear relationship when the range of EC e is relatively great ( Table 1). As shown in Table 4, the relationship EC e = fEC 1:5 using the USDA method is similar to the corresponding one reported by Kargas et al [7], (Table 1) for Greek soils since both the two equations have almost the same slope (6.61 and 6.53, respectively).…”

Evaluation and analysis of different regression models for estimation of ECe from EC1:5—With a case study from Buin‐Zahra, Iran*

“…Other researchers have reported that the coefficient value of regression models varies according to the differences in soil characteristics (soil texture, clay type, solutes types, and organic matter) (Al‐Mustafa & Al‐Omran, 1990; Chi & Wang, 2010; He et al, 2013; Khorsandi & Yazdi, 2007; Shaw, 1994; Slavich & Petterson, 1993; Sonmez et al, 2008). However, the observed result variations among various studies could be most likely attributed to the different methodologies used for EC 1:5 determination (Kargas et al, 2018).…”

“…The regression coefficients (slope) in this study were different from reported values of some studies (Chi & Wang, 2010; Loveday, Beatty, & Norris, 1972; Sonmez et al, 2008). Regression coefficients range has been reported from 6 to 11 (Chi & Wang, 2010; Kargas et al, 2018; Loveday et al, 1972), 7.36 to 8.22 (Sonmez et al, 2008), 6.9 to 5.4 (Khorsandi & Yazdi, 2007, 2011), 5.04 (Aboukila & Norton, 2017), and 7.46 (Aboukila & Abdelaty, 2017). Nevertheless, the values in other studies are much greater than the obtained values in the current study (0.44–0.66).…”

“…It can be considered as an important factor in determining the appropriate soil for the sustainable production of agricultural products. Explosive growth of human population introduces productivity necessity (Kargas et al, 2018). In order to investigate the salinity effect on plant growth, measuring the concentration of soluble salts in soil water is required at a specific moisture content.…”

Estimation of infiltration models parameters and their comparison to simulate the onsite soil infiltration characteristics

“…Soil textures were predominantly silty clay having clay fraction of 45%-50% and silt fraction of 41%-46%. Soil electrical conductivity (EC) was measured using soil saturated paste extract methodology and it was ranged from 0.68 dS/m to 0.98 dS/m [48] . The values of EC greater than 4 dS/m indicated the salinity problems [49] .…”