Analysis of water uptake of growing media on the relation to water uptake in horticultural practice
A method which describes the saturation characteristics of air dried peat was developed 20 years ago in The Netherlands. This method was set up to get an impression of the unsaturated hydraulic conductivity in a method easy to perform. This method is further developed by RHP and is called nowadays the WOK-method (Water Uptake Characteristic). It describes the velocity of water uptake of an air dried sample during 24 h by constant weighing of the sample. From the retrieved curve of water uptake in minutes, the moment when 50% of the uptake is reached is used as a characterizing parameter (W50P-value). An experiment was performed to clarify the relation between the W50P-value and the water uptake of growing media in horticultural practice of a flooded benches culture. Various growing media with differing W50P-values were tested in a large scale experiment with Impatiens 'New Guinea'. During the culture, the water content of the root ball was monitored with sensors. Dry conditions were simulated. The results of analysis of the unused growing media were compared with the behaviour of water uptake in culture, showing a significant relation between the W50P-value and the water uptake in the Impatiens culture. Thus, the W50P-value can be used as a parameter for the selection of growing media to be used for a plant culture.
Geuijen, W.H.C. and Verhagen, J.B.G.M. 2017. Analysis of water uptake of growing media on the relation to water uptake in horticultural practice. Acta Hort. (ISHS) 1168:113-118
potting soil, growing media, water uptake, unsaturated hydraulic conductivity