Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-26T05:21:22.391Z Has data issue: false hasContentIssue false
  • English
  • Français

An empirical law describing heterogeneity in the yields of agricultural crops

Published online by Cambridge University Press:  27 March 2009

H. Fairfield Smith
Get access Rights & Permissions [Opens in a new window]

Extract

Using data from a blank experiment with wheat it was found that the regression of the logarithms of the variances for plots of different areas on the logarithms of their areas was approximately linear. A graphical review of variances, etc., reported in the literature for thirty-nine other blank experiments indicates that the results of most such experiments conform to the same law.

It is shown that the above law can be generalized (so as to be applicable to any size of field) by applying a certain adjustment to the regression coefficient b', so as to give a modified coefficient b applicable to an “infinite” field.

From this generalized relationship there has been deduced an expression ((4), p. 16) to indicate average relative efficiencies to be expected for randomized block experiments with varying numbers of plots per block in a field for which the coefficient b is known.

A formulae (5), which may be used to estimate the most efficient size of plot for any given experiment, has also been deduced. The cost of using plots of other than the most efficient size is indicated graphically in Fig. 7.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 28 , Issue 1 , January 1938 , pp. 1 - 23
Copyright
Copyright © Cambridge University Press 1938

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

Christidis, B. G. (1931). J. agric. Sci. 21, 14–37.CrossRefGoogle Scholar
Cochran, W. G. (1937). J. R. statist. Soc. Suppl. 4, 233–253.CrossRefGoogle Scholar
Engledow, F. L. & Yule, G. U. (1926). The Principles and Practice of Yield Trials. Emp. Cott. Gr. Corp. London, p. 22.Google Scholar
Fisher, R. A. (1925–1936). Statistical Methods for Research Workers. Edinburgh.Google Scholar
Harris, J. A. (1915). Amer. Nat. 49, 430–54.CrossRefGoogle Scholar
Harris, J. A. (1920). J. agric. Res. 19, 279–314.Google Scholar
Wood, T. B. & Stratton, F. J. M. (1909). J. agric. Sci. 3, 417–440.CrossRefGoogle Scholar
Yates, F. (1935). J. R. statist. Soc. Suppl. 2, 181–223.CrossRefGoogle Scholar
Yates, F. (1936). J. agric. Sci. 26, 424–55.CrossRefGoogle Scholar
Yates, F. (1937). Ann. Eugen., Camb., 7, 319–32.CrossRefGoogle Scholar
Yates, F. (1937). Tech. Commun. Bur. Soil Sci., Harpenden, No. 35.Google Scholar