CSBE-SCGAB

Root extraction coefficients for soil moisture budgeting derived from measured root densities

Authors: Dyer, J. A. And L. M. Dwyer
Description: Soil water content and the availability of water is an important parameter in agricultural research and management. There is, therefore, a need to estimate soil water distribution over time and area. One approach is computer estimation of soil water distribution by a multi-zone budgeting technique (Baier et al. 1979). A criticism of this technique is that to predict changes in soil water distribution tabulated crop coefficients had to be developed empirically through trial and error to ac count for soil water loss, including ex traction by roots. In this paper we describe the derivation of crop coefficients from measured corn root densities in container plant-soil systems. These coefficients are assumed to reflect changes in root extraction over time and depth. Estimations of soil water distribution in these systems using crop coefficients in a computer budget are compared to volumetric soil water measurements obtained by a recently developed non destructive electro magnetic technique (Topp et al. 1980). The basic drying relationship used by Baier et al. (1979) in the versatile soil moisture budget (VB) is:
Keywords: root extraction coefficients for soil moisture budgeting derived from measured root densities
Citation: Dyer, J. A. and L. M. Dwyer 1982. ROOT EXTRACTION COEFFICIENTS FOR SOIL MOISTURE BUDGETING DERIVED FROM MEASURED ROOT DENSITIES. Canadian Agricultural Engineering 24(2):81-86.
Volume: 24
Issue: 2
Start page number: 81
End page number: 86
Date: 1982
Coverage: Canada
Located in: Volume 24 (1982)