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Potassium in soils under different cropping systems:2. The effects of cropping systems on the retention by the soils of added K not used by crops

Published online by Cambridge University Press:  27 March 2009

T. M. Addiscott  and
A. E. Johnston
T. M. Addiscott
Affiliation:
Rothamsted Experimental Station, Harpenden, Herts
A. E. Johnston
Affiliation:
Rothamsted Experimental Station, Harpenden, Herts
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Summary

The K balance, the difference between K added as fertilizer or farmyard manure (FYM) and K removed by the crops, was calculated for soils from the Classical and Ley-Arable experiments at Rothamsted and for the Woburn Ley-Arable experiment, for the duration of each experiment. Linear regressions on K balance accounted for 78% of the variation in exchangeable K (Ke) and for 83% in K uptake by ryegrass (KP) in the Classical experiments, for 56 and60% respectively in the Ley-Arable experiments at Rothamsted, and for 39 and 6% in the Woburn Ley-Arable experiment.

Regressions of Ke and Kp on K balance suggested that, in the Rothamsted Ley-Arable experiments, rather more than half of the K balance remained extractable by ryegrass from the plots with a rotation of crops, and apparently all of the K balance from those under continuous grass. About one-fifth of the K balance remained extractable by ryegrass from the soils in the Rothamsted Classical experiments and soils given FYM retained K slightly better than other soils. With all soils about half the K extractable by ryegrass was exchangeable to ammonium acetate.

The plots with FYM or under continuous grass contain more organic matter than other plots in the same experiments. The following possible effects of increasing the organic matter content of the soils were investigated by calculating the multiple regressions of K, and KB on K balance with either percentage of organic C, total CEC, or organic CEC:

(1) loss of K decreased by increasing the water retention and lessening leaching;

(2) improved K retention by increasing the total cation exchange capacity (CEC) available for K absorption;

(3) improved K retention by a mechanism arising from the different selectivities of clay and organic matter for K relative to Ca.

In the Classical experiments, where organic matter usually increases because of FYM additions, effect (2) seems the most probable, perhaps because the K given in the FYM was already absorbed by organic exchange sites. In the Ley–Arable experiments, where the K was given mainly as soluble K fertilizer and the organic matter develops mainly under grass, effects (1) or (3) seemed to operate, probably simultaneously.

The Woburn Ley-Arable experiment had no continuous grass plots, the soils differed little in organic matter content and no deductions could be made.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 76 , Issue 3 , June 1971 , pp. 553 - 561
Copyright
Copyright © Cambridge University Press 1971

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References

REFERENCES

Addiscott, T. M. (1970a). A note on resolving soil cation exchange capacity into ‘mineral’ and ‘organic’ fractions. J. agric. Sci., Camb. 75, 365–7.CrossRefGoogle Scholar
Addiscott, T. M. (1970b). Potassium: calcium exchange in soils of the Broadbalk experiment at Rothamsted. J. agric. Sci., Camb. 75, 451–7.CrossRefGoogle Scholar
Bascomb, C. L. (1964). Rapidmethodfor the determination of cation exchange capacity of calcareous and non-calcareous soils. J. Sci. Fd Agric. 15, 821–3.CrossRefGoogle Scholar
Bremner, J. M. & Jenkinson, D. S. (1960). Determination of organic carbon in soil. I. Oxidation by dichromate of organic matter in soil and plant materials. J. Soil Sci. 11, 394–402.CrossRefGoogle Scholar
Chambers, W. E. (1953). Nutrient content of the produce of the Broadbalk continuous wheat experiment. I. Changes over seventy years. J. agric. Sci., Camb. 43, 473–8.CrossRefGoogle Scholar
Cooke, G. W., Mattingly, G. E. G. & Williams, R. J. B. (1958). Changes in the soil of a long continued field experiment at Saxmundham, Suffolk. J. Soil Sci. 9, 298–305.CrossRefGoogle Scholar
Johnston, A. E. (1969). The Broadbalk wheat experiment. Plant nutrients in Broadbalk soils. Bep. Bothamsted exp. Stn for 1968, pt 2, pp. 93–115.Google Scholar
Johnston, A. E. & Garner, H. V. (1969). The Broadbalk wheat experiment. Historical Introduction. Bep. Bothamsted exp. Stn for 1968, pt 2, pp. 12–25.Google Scholar
Johnston, A. E. & Addiscott, T. M. (1971). Potassium in soils under different cropping systems. 1. Behaviour of K remaining in soils from Classical and Rotation experiments at Rothamsted and Woburn and evaluation of methods of measuring soil potassium. J. agric. Sci., Oamb. 76, 539–52.CrossRefGoogle Scholar
Jones, U. S. (1947). Availability of humate potassium. Proc. Soil Sci. Soc. Am. 12, 373–8.CrossRefGoogle Scholar
Pratt, P. F. & Grover, B. L. (1964). Monovalentdivalent cation exchange equilibria in soils in relation to organic matter and type of clay. Proc. Soil Sci. Soc. Am. 28, 32–5.CrossRefGoogle Scholar
Rothamsted Experimental Station (1968). Field Experiments and Work of the Departments. 79 pp. Harpenden.Google Scholar
Rothamsted Experimental Station (1970). Details of the Classical and Long-Term Experiments up to 1967. 128 pp. Harpenden.Google Scholar
Salmon, R. C. (1964). Cation exchange reactions. J. Soil Sci. 15, 273–83.CrossRefGoogle Scholar
Salter, P. J. & Williams, J. B. (1969). The moisture characteristics of some Rothamsted, Woburn and Saxmundham soils. J. agric. Sci., Camb. 73, 155–8.CrossRefGoogle Scholar
Skarda, M. (1967). Effect of fertilising on the potassium balance in soil. Úst. vĕd. Inf. MZLH Rostl Vyroba 40, 271–84. (Soils and Fertil. 30, 2450.)Google Scholar
Tinsley, J. (1950). The determination of organic carbon in soils by dichromate mixtures. Trans 4th Int. Cong. Soil Sci. 1, 161–4.Google Scholar
Vreis, P. De (1966). Control of the potassium value on permanent pasture. Meded. Inst. Biol. scheik. Onderz LandbGewass. no. 307, pp. 44. (Soils and Fertil. 30, 60.)Google Scholar
Warren, R. G. & Johnston, A. E. (1962a). The accumulation and loss of soil potassium in long-term experiments, Rothamsted and Woburn. Proc. Fertil. Soc. 72, 5–24.Google Scholar
Warren, R. G. & Johnston, A. E. (1962b). Barnfield. Rep. Rothamsted exp. Stn for 1961, pp. 227–47.Google Scholar
Warren, R. G. & Johnston, A. E. (1967). Hoosfield Continuous Barley. Rep. Rothamsted exp. Stn for 1966, pp. 320–38.Google Scholar