Validity of Centrifuge-based Method for Determining Water Retention Curve of Growing Media

This study presented a centrifuge-based method for determining hydraulic properties in growing media, offering insights into water dynamics in growth substrates. The objectives of this study were to test the practical applicability of the centrifuge method as a quick test for a wide range of growing media, ii) to compare a simple substitution method to describe the bulk density of growing media with results of the standard method, and iii) to give a recommendation under which conditions the centrifuge quick test could serve as a replacement for the standard method. Methods involved centrifugation and correlation analyses. Results showed good agreement between the centrifuge and DIN methods, with notable compression effects at lower pF stages. The method's rapidity (2 days vs. up to 8.5 days) and correlation with standard methods highlight its potential for practical applications. Limitations, such as compression effects, were noted, emphasizing the need for careful interpretation. Overall, the centrifuge method provided a valuable tool for research and substrate development. This study contributes to refining measurement techniques in growth substrates, encouraging ongoing research in water dynamics in growing media.