Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-30T20:19:14.783Z Has data issue: false hasContentIssue false

The potassium Q/l relationships of soils given different K manuring

Published online by Cambridge University Press:  27 March 2009

T. M. Addiscott
Affiliation:
Rothamsted Experimental Station, Harpenden, Herts.

Summary

The potassium quantity/intensity (Q/I) relationships, which relate change in exchangeable K content (Q) to change in activity ratio were measured in soil samples from manuring experiments at Rothamsted and Woburn. Within each experiment, Q/I curves for different K-manuring treatments were super-imposable on each other and on the curve relating exchangeable K to Io, the activity ratio at which the soil neither gains nor loses K. The distances on the Q axis between the curves were equal to the differences in exchangeable K.

The buffer capacity, dQ/dI, was related to the K saturation of the cation exchange capacity (CEC) by the equations

(Q and CEC in m-equiv/100 g)

Broadbalk and Hoosfield soil, and

for Barnfield soils (b= 3·08; m= 1·0) and for Woburn market garden soils (b =2·41; m= 0·6) but for soils from other Woburn experiments, dQ/dl did not vary significantly with Q/CEC.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1970

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Avery, B. W. (1964). The soils and land use of the district round Aylesbury and Hemel Hempstead. Mem. Soil Surv. Gt. Br.Google Scholar
Bascomb, C. L. (1964). Rapid method for the determination of cation exchange capacity of calcareous and non-calcareous soils. J. Sci. Fd Agric. 15, 821–3.CrossRefGoogle Scholar
Beckett, P. H. T. (1964 a). The immediate Q/I relations of labile potassium in the soil. J. Soil Sci. 15 (1), 923.CrossRefGoogle Scholar
Beckett, P. H. T. (1964 b). Potassium-calcium exchange equilibria in soils: specific adsorption sites for potassium. Soil Sci. 97, 376–83.CrossRefGoogle Scholar
Beckett, P. H. T. (1965). Activity coefficients for studies on soil potassium. Agrochimica 9 (2), 150–2.Google Scholar
Beckett, P. H. T., Craig, J. B., Natady, H. M. H. & Watson, J. P. (1966). Studies on soil potassium. V. The stability of Q/I relations. Pl. Soil 25 (3). 435–55.CrossRefGoogle Scholar
Beckett, P. H. T. & Nafady, H. M. H. (1967). Studies on soil potassium. VI. The effect of K fixation and release on the form of the K:Ca+Mg exchange isotherm. J. Soil Sci. 18, (2), 244–62.CrossRefGoogle Scholar
Bolt, G. W., Sumner, M. E. & Kamphorst, A. (1963). A study of the equilibria between three categories of potassium in an illitic soil. Proc. Soil Sci. Soc. Am. 27, 294–9.Google Scholar
Schofield, R. K. & Taylor, A. W. (1955). Measurements of the activities of bases in soils. J. Soil Sci. 6 (1), 137–46.CrossRefGoogle Scholar
Talibudeen, O. & Dey, S. K. (1968). Potassium reserves in British soils. I. The Rothamsted Classical Experiments. J. agric. Sci., Camb. 71, 95104.CrossRefGoogle Scholar
van Schouwenburg, J. Ch. & Schuffelen, A. C. (1963). Potassium exchange behaviour of an illite. Neth. J. agric. Sci. 11, 1322.Google Scholar