Using TDR to Estimate Hydraulic Conductivity and Air Entry in Growing Media and Sand

摘要: Gas relative diffusivity measurements are key indicators of the quality growing media. Previous studies have shown that this property can be estimated indirectly from point air entry (ψ a ), air-filled porosity (θ and saturated hydraulic conductivity (K s ). Different tools required to measure these parameters paper investigates how single tool, time domain reflectrometry (TDR), already used determine θ volumetric water content (θ), could utilized ψ K in Cylinders were filled with 13 different substrates coarse sand. A transient-state technique (vertical infiltration at -1 hPa potential) was calculate time. In media, calculated values experiment statistically equal estimates obtained steady-state potential -1hPa. However, both methods underestimated K, under conditions after pulse had been applied or prolonged wetting. For sand, TDR-based hPa, provided those saturation. To estimate , TDR probes horizontal vertical position tested addition pressure transducer technique. positioning more consistent than other two techniques. Estimates position, similar.