Short communication: Predicting cation exchange capacity from hygroscopic moisture in agricultural soils of Western Europe

José Torrent, María C. del Campillo, Vidal Barrón

Abstract


Soil cation exchange capacity (CEC) depends on the extent and negative charge density of surfaces of soil mineral and organic components. Soil water sorption also depends on the extent of such surfaces, giving thus way to significant relationships between CEC and hygroscopic moisture (HM) in many soils. In this work, we explored whether CEC could be accurately predicted from HM in agricultural soils of Mediterranean and humid temperate areas in Western Europe. For this purpose, we examined 243 soils across a wide variation range of their intrinsic properties. Soil CEC was determined using 1 M ammonium acetate at pH 7 and HM at an equilibrium air relative humidity (RH) of 43% (HM43). Most of the variation of soil CEC was explained by HM43 through a linear function (CEC = 1.4 + 0.78HM43; R2 = 0.962; standard deviation = 2.30 cmolc/kg). Coefficients of the regression equation were similar for subgroups of soils differing in moisture regime, clay mineralogy, carbonate content and organic carbon content. Therefore, soil hygroscopic moisture measurements at a fixed RH level provided a simple, robust, inexpensive method for predicting soil CEC.


Keywords


soil organic carbon; relative humidity

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References


Churchman GJ, Burke CM, 1991. Properties of subsoils in relation to various measures of surface area and water content. J Soil Sci 42: 463–478. http://dx.doi.org/10.1111/j.1365-2389.1991.tb00423.x

Churchman GJ, Burke CM, Parfitt RL, 1991. Comparison of various methods for the determination of specific surfaces of subsoils. J Soil Sci 42: 449–461. http://dx.doi.org/10.1111/j.1365-2389.1991.tb00422.x

Manrique LA, Jones CA, Dyke PT, 1991. Predicting cation-exchange capacity from soil physical and chemical properties. Soil Sci Soc Am J 55: 787–794. http://dx.doi.org/10.2136/sssaj1991.03615995005500030026x

Newman ACD, 1983. The specific surface of soils determined by water sorption. J Soil Sci 34: 23–32. http://dx.doi.org/10.1111/j.1365-2389.1983.tb00809.x

Quirk JP, 1955. Significance of surface areas calculated from water vapor sorption isotherms by use of the B.E.T. equation. Soil Sci 80: 423–429. http://dx.doi.org/10.1097/00010694-195512000-00001

Sánchez-Alcalá I, del Campillo MC, Barrón V, Torrent J, 2014. The Olsen P/solution P relationship as affected by soil properties. Soil Use Manage 30: 454–462. http://dx.doi.org/10.1111/sum.12141

Soil Survey Staff, 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys, 2nd edition. Natural Resources Conservation Service. U.S. Department of Agriculture Handbook 436. 871 pp.




DOI: 10.5424/sjar/2015134-8212