ekS - Instytut Agrofizyki im. Bohdana DobrzaÅskiego PAN w Lublinie ...
ekS - Instytut Agrofizyki im. Bohdana DobrzaÅskiego PAN w Lublinie ...
ekS - Instytut Agrofizyki im. Bohdana DobrzaÅskiego PAN w Lublinie ...
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[72]). These particles of water have the dielectric constant lower than that of free<br />
water. Therefore the model (27) is not adequate for clayey soils.<br />
The value of dielectric constant of bound water, ε bw , increases with the<br />
distance from the solid particles. Dirksen and Dasberg [27] confirmed this for<br />
soils of high specific surfaces.<br />
Fig. 12.<br />
Relation between the soil relative dielectric constant, ε, and soil volumetric water<br />
content, θ, for the investigated mineral soils. The solid line represents the empirical<br />
model (31) calculated for the average bulk density of the soil samples 1.42 [gcm -3 ]<br />
The comparison of ε values calculated from the 3-phase model (27) and<br />
measured by TDR device is presented in Fig. 13. There are two distinct ranges of<br />
ε, below and above the transition value of ε TDR ≅ 15, and this distinction generally<br />
does not depend on the value of the parameter α.<br />
Fig. 13.<br />
Comparison of soil relative dielectric constants of the investigated soil samples<br />
measured by TDR method (horizontal axis) and calculated from 3-phase model α (27)<br />
for different values of α parameter.<br />
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