soil Series of Articles on Soilless Potting Mix (and pH measurment and adjustment)

[orangehero]

Hello,
 
I came across this five part series of articles on soilless potting mixes by Professor Bob Tripepi on the University of Idaho Extension website titled What Is Your Substrate Trying to Tell You.
 
What was useful for me is that he goes in depth into pH measurement and adjustment, but I think anyone that wants more technical information on how to analyze and formulate substrates for growing in containers will find them useful.
 
Summary
"Substrates can tell us many things, if we know what properties to examine. We should determine several chemical and physical properties BEFORE planting the crop in the substrate. Among the most important chemical properties to examine are pH, CEC, EC, and C:N. pH and EC of the substrate should be determined before planting and as the crop continues to grow, since pH controls nutrient availability and EC indicates salinity of the medium. pH can be controlled by fertilizers or water used as well as the preplant ingredients. Several extraction ethods can be used on substrates to enable you to determine the pH and EC of mixes. Air capacity, water-holding capacity, and total porosity of a substrate are the physical properties to measure to help you determine if the crop may grow well. Even if chemical and physical properties of a substrate appear to be satisfactory, growing plants in a mix is the ultimate indicator of medium suitability for crop production." (Emphasis mine.)
 
Source: http://www.extension.uidaho.edu/nursery/NTRC%20Substrate.htm
 
Part 1: http://www.extension.uidaho.edu/nursery/Landscape%20problems/Substrate/pH%20and%20EC%20of%20soilless%20media.PDF
 
Part 2: http://www.extension.uidaho.edu/nursery/Landscape%20problems/Substrate/CEC%20and%20CN%20ratio.PDF
 
Part 3: http://www.extension.uidaho.edu/nursery/Landscape%20problems/Substrate/Measuring%20pH%20and%20CEC.PDF
 
Part 4: http://www.extension.uidaho.edu/nursery/Landscape%20problems/Substrate/Physical%20characteristics.PDF
 
Part 5: http://www.extension.uidaho.edu/nursery/Landscape%20problems/Substrate/Chemical%20and%20physical%20analysis.PDF
 
In fact there are many other great publications from them.
 
More information on measuring and adjusting pH of substrates.

 

[Jeff H]

Looks like something I need to read. Thanks for posting.

 

[capsidadburn]

Very useful indeed.  Thank you!

 

[Jeff H]

For anyone not wanting to read through all of them just to figure out if they are useful or not, I can tell you that learning how to take the pH and EC of a soil mix was well worth the time it took to read the articles. The last link posted has a real world way to do this but the 5 part article tells you why this is important.