Director Christine Shaw
Many of the underlying principles in the contribution of these factors have been touched on before (Weather Station and Cereals)
For the purpose of detailing the impact of weather on the outcome of experiments, particularly crop yield experiments, it is crucial to appreciate that it is essential to experiment for a lengthy period, sufficient to incorporate the likely long-run effects of the "weather cycle", during which both the extremes of weather and "runs" of wet or dry periods (say) will be likely to occur. By way of example from another area, the Environment Agency designs its schemes on the basis of a 20 year "return period". The Butser principle has been to seek to run trials on the same site for periods approaching this, although circumstances beyond the Director's control have so far prevented this being completely achieved. Because work has been displaced from some sites at different times, the comparisons between results for different sites with different soils and different micro-climates are not fully contemporaneous. This in no way invalidates the comparison, because they are in general for extensive intervals.
Up till now the above criterion of "length of run" has not justified full publication of the data against the laid down objective. From time to time results have been given in outline for specific demands. These publications are about to be drawn together for an over-view, in conjunction with the fuller data sets now available. This is felt to be particularly urgent, because of the recent publication of a short-term study of dubious validity. The detailed critique of that paper and the author's reply will be made available in these pages, once the full review is done and the newer work can be put into proper context.
Students wishing to get a better and more balanced insight into long term weather patterns are recommended to read Burroughs (1992/1994).
Reference.
Burroughs, William James "Weather Cycles: Real or
Imaginery?" Cambridge University Press 1992
(First paperback edition 1994).
Return to Uncontrolled Factors
Created 01 August 2001 - Updated 22 January 2002