Barley and its environment. 1. Theory and practice.
Abstract
In an investigation of the relation between weather and the growth of barley, the approach used depended on calculation of the exchange of CO2 and water vapour between the crop and the atmosphere using the Bowen ratio and aerodynamic methods. The basic transfer equations used in both methods were extended to exploit measurements at a set of levels above the canopy rather than the more traditional method of using 2 levels only. The sensing and recording instruments used in the experiment are fully described together with details of the site and crops on which the measurements were made. Data analysis depended on the use of a large computer because measurements were made continuously throughout the growing season. Programming methods are outlined and illustrated by samples of the output. Good agreement was demonstrated between fluxes of CO2 calculated by the Bowen ratio and aerodynamic methods, and the advantages of using multipoint profiles were clearly shown.