Analytical methods used with soilless substrates serve to select the most suitable growing media for a particular application, to compare growing media and to allow quality control for production and trade. Analytical methods also provide the standardized data needed by fertilizer recommendation systems. Assessing a growing medium for an application often requires the combined interpretation of several measured properties as well as the interpretation of the influence of the crop, water supply and nutrient supply systems. As in the related soil sciences, methods are grouped as physical (e.g. water retention characteristics and dry bulk density), chemical (e.g. available nutrients and electrical conductivity) and biological methods (e.g. stability and plant response). The methods are described with separate paragraphs dedicated to the units used, special cases, common values, and the relation to crop growth. A development in practice is the interest in methods which are more dynamic. At present most laboratory methods deliver answers under static conditions, but the plant uptake of water, nutrients, and oxygen by plants is usually highly variable over the course of a day. Another development is the supply of materials from other industries, such as composts, digestates, biochars, and spent mushroom casing which come with quality parameters used in those supplying industries. Important issues are the choice of extraction methods and the expression of water content and organic matter in % V/V. A third development is the interest in the evolution of growing media properties during cultivation as over time, properties may change due to the actions of e.g. root growth and bacterial activity.
|Title of host publication||Soilless Culture|
|Subtitle of host publication||Theory and Practice Theory and Practice|
|Editors||M. Raviv, J.H. Lieth, A. Bar-Tal|
|Number of pages||56|
|Publication status||Published - 5 Apr 2019|
- Rooting media
- Water characteristics