Summary
An alcohol displacement method is used to obtain equilibrium soil solutions from three soils set up over a moisture content range of 25–10,000 per cent. A considerable change of concentration of ions occurs with time of contact between the soil and its solution phase, equilibrium being attained between 30 to 40 days. A decreasing cation concentration gradient was demonstrated with increasing moisture content with a particularly sharp gradient over the field range of moisture. The activity ratio expressed in negative logarithm form, pK−1/2p(Ca+Mg), was calculated from the ion concentrations and the Debye-Hückel second approximation. These values were constant for one of the soils over the entire moisture content range whilst they were only constant over the field range of moisture for the other two soils. Constancy of the value of pK−1/2p(Ca+Mg) indicates an undisturbed equilibrium, the value defining the characteristic potassium intensity status of that soil.
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Literature cited
Anderson, M. S., Keyes, M. G. and Cramer, G. W., Soluble material of soils in relation to their classification and general fertility. U.S. Dept. Agr. Tech. Bull.813 (1942).
Burd, J. S. and Martin, J. C., Water displacements of soils and the soil solution. J. Agr. Sci.13, 265–295 (1923).
Cameron, F. K., The Soil Solution: The Nutrient Medium for Plant Growth. The Chemical Publ. Co. Easton Penn. (1911).
Chenery, E. M., The Soils of Central Trinidad. Government Printing Office (1952).
Coleman, J. D., An investigation of the pressure membrane method for measuring the suction properties of soil. D. S. I. R. Road Research Note No. RN/3464/JDC. BS. 408.
Emerson, W. W., The rate of water uptake of soil crumbs at low suctions. J. Soil Sci.6, 1, 147–159 (1955).
Ishcherekov, V., The obtaining of the soil solution in an unaltered condition. Zhur. Opytn. Agron. V8, 147–166 (1907).
Ivanov, A. N. and Gapon, E. N., Ion exchange between solid and liquid phases. I. Dependence of cation exchange upon dilution. II. Differential coefficients of sorption of two ions. Zhur. Fiz. Khim.15, 659–664 and 665–672 (1941).
Kemper, W. D., Water and ion movement in thin films as influenced by the electrostatic charge and diffuse layer of cations associated with clay mineral surfaces. Soil Sci. Soc. Am. Proc.24, 10–16 (1960).
Klute, A. and Letey, J., The dependence of ionic diffusion on the moisture content of non adsorbing media. Soil Sci. Soc. Am. Proc.22, 213–215 (1958).
Komarova, N. A., The displacement of soil solution by the methods of replacement by liquids and the use of the method in soil investigations. Trudy Pochvennogo Inst. Dokuchaeva Akad. Nauk S.S.S.R.51, 5–97 (1956).
Krishnamorthy, C. and Desai, A. D., Kinetics of exchange between adsorbents: IV. Unequal valency ion pairs. Soil. Sci.80, 325–333 (1955).
Kurchatov, P. A. and Kozlikhin, A. D., The influence of the dilution of soils on the amount of cations adsorbed by the soils. Trudy Belorus. Sel'skokhoz. Inst.8, No. 30, 11–19 (1939).
Lewis, L. L. and Melnich, L. M., Determination of calcium and magnesium with EDTA. Studies in accuracy. Anal. Chem.32, 38–42 (1960).
Lisk, D. J., Chemical composition of soil solution. Ph.D. Thesis, Cornell University, U.S.A. (1956). Dissertation Abstr.17, 457–8 (1957).
Magistad, O. C., Fireman, M., and Mabry, B., Comparison of base exchange equations founded on the law of mass action. Soil Sci.57, 371–9 (1944).
Mattson, S. and Wiklander, L., The laws of soil colloidal behaviour: XXIA. The amphoteric points, the pH and the Donnan equilibrium. Soil Sci49, 109–134 (1940).
Moss, P., Limits of interference by iron, manganese, aluminium and phosphate in the EDTA determination of calcium in the presence of magnesium using cal-red as indicator. J. Sci. Food Agr.12, 30–34 (1961).
Olsen, R. A., Characterization of the ionic environment of plant roots in the soil. Ph. D. Thesis, Cornell University, U.S.A. (1953).
Olsen, R. A. and Peech, M., The significance of the suspension effect in the uptake of cations by plants from soil-water systems. Soil Sci. Soc. Am. Proc.24, 2, 257–261 (1960).
Overbeek, J. T. G., Electrochemistry of the double layer.In: Kruyt, H. R. Colloid Science1, 115–193 (1952).
Parker, F. W., Methods of studying the concentration and composition of the soil solution. Soil Sci.12, 209–232 (1921).
Patton, J. and Reeder, W., New indicator for titration of calcium with ethylenedinitrilo tetracetate. Anal. Chem.28, 6, 1026–1028 (1956)
Richards, L. A., A pressure membrane extraction apparatus for soil solution. Soil Sci51, 377–86 (1941).
Schofield, R. K., A ratio law governing the equilibrium of cations in the soil solution. Proc. XI Internat. Congr. Pure and Appl. Chem.3, 257–261 (1947).
Schofield, R. K. and Taylor, A. W., The measurement of soil pH. Soil Sci. Soc. Amer. Proc.19, 164–167 (1955).
Schuffelen, A. C. and Bolt, G. H., Ionic equilibria in soils. Intern. Soc. Soil Sci. Trans. II and IV. Comm., Hamburg2, 132–146 (1958).
Spector, J., Mutual interferences and elimination of calcium interrerences in flame photometry. Anal. Chem.27, 1452–1455 (1955).
Taylor, A. W., Some equilibrium solution studies on Rothamsted Soils. Soil Sci. Soc. Am. Proc.22, 6, 511–513 (1958).
Woodruff, C. M., Ionic equilibrium between clay and dilute salt solutions. Soil Sci. Soc. Am. Proc.19, 1, 36–40 (1955).
Woodruff, C. M., Cation activities in the soil solution and energies of cation exchange. Soil Sci. Soc. Am. Proc.19, 1, 98–99 (1955).
Woodruff, C. M., The energies of replacement of calcium by potassium in soils. Soil Sci Soc. Am. Proc.19, 2, 167–171 (1955).
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Moss, P. Some aspects of the cation status of soil moisture. Plant Soil 18, 99–113 (1963). https://doi.org/10.1007/BF01391684
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DOI: https://doi.org/10.1007/BF01391684