Articles
PROSPECTS FOR BIOLOGICAL CHARACTERIZATION AND EVALUATION OF GROWING MEDIA
Article number
819_9
Pages
99 – 110
Language
English
Abstract
Growing media are commonly evaluated with respect to their physical and chemical properties.
Among biological properties, absence of pathogens and weed seeds are usually claimed.
A more thorough biological characterization of growing media is required for several reasons: (i) reuse of growing media as a result of reduced external input into horticultural cropping systems for both ornamentals and vegetables; as the parent material of growing media may be of inorganic or organic nature, it is susceptible to different microbially mediated processes and changes; and (ii) plant health aspects related to growing media at different stages of use.
Biological variables may be used to secure quality in a static and dynamic way.
A rationale for biological properties in growing media on the basis of carbon turn-over is presented.
Growing media may be biologically described on the basis of quantitative and functional variables, of microbial community structure or by methods describing plant-microbe interactions.
These variables are appropriate for description of biological status but do not allow any conclusions on the biological performance of the growing medium in a dynamic way.
This latter point may be mediated by indirect variables.
Plants are used as bio-indicators for description of disease complexes and suppressiveness.
Total and dissolved organic carbon content, activity of specific enzymes and the occurrence of some organic key compounds are indicators for the potential production of antagonistic compounds.
Biological characterization of growing media is a powerful tool to tailor growing media with respect to both of the above named requirements.
Further research is needed for dynamic on-line in situ evaluation.
Among biological properties, absence of pathogens and weed seeds are usually claimed.
A more thorough biological characterization of growing media is required for several reasons: (i) reuse of growing media as a result of reduced external input into horticultural cropping systems for both ornamentals and vegetables; as the parent material of growing media may be of inorganic or organic nature, it is susceptible to different microbially mediated processes and changes; and (ii) plant health aspects related to growing media at different stages of use.
Biological variables may be used to secure quality in a static and dynamic way.
A rationale for biological properties in growing media on the basis of carbon turn-over is presented.
Growing media may be biologically described on the basis of quantitative and functional variables, of microbial community structure or by methods describing plant-microbe interactions.
These variables are appropriate for description of biological status but do not allow any conclusions on the biological performance of the growing medium in a dynamic way.
This latter point may be mediated by indirect variables.
Plants are used as bio-indicators for description of disease complexes and suppressiveness.
Total and dissolved organic carbon content, activity of specific enzymes and the occurrence of some organic key compounds are indicators for the potential production of antagonistic compounds.
Biological characterization of growing media is a powerful tool to tailor growing media with respect to both of the above named requirements.
Further research is needed for dynamic on-line in situ evaluation.
Publication
Authors
B.W. Alsanius, W. Wohanka
Keywords
bio-assay, carbon turn-over, community level physiological profiles (CLPP), denaturing gradient gel electrophoresis (DGGE), direct cell count, enzyme activity, functional analysis, microbial diversity and community structure, molecular markers, plant-microbe interactions, plate count, quantitative analysis, respiration, phospholipid fatty acid (PLFA) profiles, sampling, viable count
Online Articles (56)