Evaluation should include identifying
- physical properties of soilless substrates
- bulk density
- moisture content
- water-holding capacity
- air-filled porosity
- porosity
- chemical properties of soilless substrates
- pH
- electrical conductivity (EC)
- cation exchange capacity (CEC)
- organic carbon content
- organic matter content
- nitrogen, phosphorus, and potassium content
- carbon-to-nitrogen (C/N) ratio
- ability to support the plant
- ability to provide air, water, and nutrients to the roots
- biological characteristics
- consequences of the C/N ratio for the biostability of organic materials
- the substrate availability to welcome and keep phytopathogen or beneficial microorganisms (e.g., fungi, bacteria)
- use of organic and inorganic amendments
- phytotoxicity
- pathogens
- selecting materials based on the environment, species to be cultivated, cultivation phase, and system of cultivation.
Process/Skill Questions:
- What are the important characteristics of soil?
- How is land classified?
- What is the composition of the ideal soil?
- What are four things that plants receive from soil?
- What components are commonly used in potting media, and what are their functions?