Water retained by various soil ingredients

David Pilling pbs@pilling.demon.co.uk
Tue, 30 Oct 2012 15:19:27 PDT

Mike said:

Metric: 118 ml of sand retained 28 grams of water, or .24g of water per 
ml of sand.

To convert his results to a dimensionless ratio, multiply them by 0.24.

When I did similar tests I got (as ratios).

sand 0.28
vermiculite 0.48
perlite 0.28
peat 0.58

I tried to measure the amount of water retained and the amount of air 
after the pot drained. I measured how much water I could get into a 
fixed volume of the medium, then how much drained over 24 hours. Perlite 
showed the greatest air content.

This is a good page about kitty litter and other substances which can be 


David Pilling
email: david@pilling.demon.co.uk
   web: http://www.davidpilling.net/

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