Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-14T04:57:08.579Z Has data issue: false hasContentIssue false
  • English
  • Français

The relationship between phosphate response and base saturation in acid soils

Published online by Cambridge University Press:  27 March 2009

H. F. Birch
H. F. Birch
Affiliation:
East African Agriculture and Forestry Research Organization, Kikuyu, Kenya
Get access Rights & Permissions [Opens in a new window]

Extract

In three groups of field experiments totalling fiftysix observations phosphate responses were found to be very significantly and inversely related both to the percentage saturation of the b.e.c. and exchangeable calcium as a percentage of exchangeable calcium plus hydrogen. The availability of the native soil phosphate was significantly and directly related to these values. The relationships between phosphate response or availability and the amounts of acid-soluble, adsorbed and water-soluble phosphate in the soils were much less conclusive.

In acid soils considerable amounts of phosphate can be retained in a plant-available form associated with exchangeable bases, mainly calcium. Since practically all the soils from the field experiments lay within the range pH 4·7–6·3, it is believed that this form of phosphate is operative in these soils. The presence of such phosphate in the soil is, however, a function of the degree of base saturation in so far as this governs (probably through its influence on soil pH) the equilibrium distribution of the native soil phosphate between the available base-linked (saloid-bound) form and the less available colloid-bound form. With decreasing pH and base saturation increasing amounts of colloid-bound phosphate are formed at the expense of the saloid-bound phosphate. The degree of base saturation is therefore directly related to phosphate availability and, consequently, inversely related to phosphate response.

In view of the significant regressions obtained, and the association of the exchangeable bases with a specific form of available phosphate, it is suggested that until methods are worked out for determining the amount of saloid-bound phosphate exchangeable base data may be used for assessing phosphato availability and response in acid soils. This method is contrasted with the more conventional methods of determining acid-soluble and adsorbed phosphates which are not always specific regarding tho form of phosphate extracted and the values for which, since they may represent the sum of a number of forms of different availabilities, aro difficult to interpret.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 42 , Issue 3 , July 1952 , pp. 276 - 285
Copyright
Copyright © Cambridge University Press 1952

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

Allison, L. E. (1943). Soil Sci. 55, 333.CrossRefGoogle Scholar
Barbier, G. & Chabannes, J. (1949). Ann. Agron. 19, 343.Google Scholar
Black, I. A. & Smith, E. (1950). J. Sci. food Agric. 1, 201.CrossRefGoogle Scholar
Bray, R. H. & Kurtz, L. T. (1945). Soil Sci. 59, 39.CrossRefGoogle Scholar
Burd, J. S. (1948). Soil Sci. 65, 227.CrossRefGoogle Scholar
Davis, F. L. & Brewer, C. A. (1940). J. Amer. Soc. Agron. 32, 419.CrossRefGoogle Scholar
Mattson, S. & Karlsson, N. (1938). Ann. Agric. Coll. Sweden, 6, 109.Google Scholar
Mattson, S., Williams, E. C., Eriksson, E. & Vartkas, K. (1950). Ann. Agric. Coll. Sweden, 17, 64.Google Scholar
Ravikovitch, S. (1934 a). Soil Sci. 38, 219.CrossRefGoogle Scholar
Ravikovitch, S. (1934 b). Soil Sci. 38, 279.CrossRefGoogle Scholar
Ravikovitch, S. (1939). Soil Sci. 47, 357.CrossRefGoogle Scholar
Salter, R. M. & Barnes, E. E. (1935). Bull. Ohio Agric. Exp. Sta. no. 553.Google Scholar
Smith, A. M. & Simpson, K. (1950). J. Sci. Food Agric. 1, 208.CrossRefGoogle Scholar
Terminology Committee (1949). Proc. Soil Sci. Soc. Amer. 14, 401.Google Scholar
Wiklander, L. (1950). Ann. Agric. Coll. Sweden, 17, 407.Google Scholar
Williams, C. H. (1950). J. Agric. Sci. 40, 233.CrossRefGoogle Scholar