Small plots and automatic rain shelters: a field appraisal

Abstract

SUMMARY Two rain shelters, each covering an area of 210 m 2 , have been built at Rothamsted for use in tillage experiments and drought experiments. Each shelter automatically moves over the experimental area when rain starts, and moves away when rain stops; thus all rain is kept off, but other aspects of the microclimate are little affected. Small experimental plots were used, and, except in the 0·5 m strips at the plot edges, the height and yield of a barley crop were uniform. Irrigation water to some plots was labelled with tritium; when applied to very dry plots, a measurable proportion of this water moved laterally by more than 1·0 m. However, the total quantity of water transferring between adjacent plots was not large enough to inconvenience the tillage or drought experiments.