Innovations in Soil Chemical Analyses: New ECs and Total Salts Relationship for Abu Dhabi Emirate Soils

Abstract

Soil analysis is important to understand composition of soils for many reasons including developing soil management options for sustainable agricultural activities. There exists a relationship between total soluble salts (meq l−1) and ECs (dS m−1) developed in 1954 and published in the USDA Handbook 60. In the present study, an attempt has been made to correlate total soluble salts and ECs values from a range of soils from Abu Dhabi Emirate to test the validity of USDA relationship to local soils. The USDA ratios (TSS/ECs) of 10 and 16 exist for ECs 1 and 200 dS m−1, respectively (R 2 = 0.9577). Whereas TSS/ECs ratio from Abu Dhabi Emirate soils was found to be 10 and 11.38 for ECs 1 and 200 dS m−1, respectively, and for ECs 500 dS m−1 a ratio of 12 was found (R 2 = 0.9711), the USDA does not present such a ratio for ECs more than 200 dS m−1. The present study has rejected the hypothesis that same relationship exists between TSS/ECs on soils of Abu Dhabi Emirate as that of USDA and, therefore, this relationship cannot be used for Abu Dhabi Emirate conditions. This chapter presents a new ratio for Abu Dhabi soils to avoid misinterpretation of soil analytical data for quality assurance (QA) purposes and to formulate soil management options. The newly developed relationship was validated by measuring sodium adsorption ratio (SAR) by various methods, that is, using Na derived by difference between TSS and Ca + Mg and through measured Na and Ca + Mg values from Abu Dhabi Soil Survey. The SAR calculated by using Na derived from newly developed relationship fits close to the SAR values from actually measured Na and Ca + Mg contents; these SAR values deviate to those measured from USSL and USDA relationships. In the light of present finding, it is recommended that other regions where soil and environmental conditions are similar to Abu Dhabi Emirate, a similar relationship most suited to their local conditions should be developed or the results to be correlated with that established from Abu Dhabi soils for validation.