COMPARISON OF PHYSICAL ANALYSIS OF PEAT SUBSTRATES.
When extremely wet substrates are filled in a cylinder and compressed, the wetness influences the later in that cylinder found volume air content at a certain pressure head. The higher the wetness the lower the volume air content.
The densities of peat substrates occuring in pots for pot plant production and packs for bedding plants are approximately 1.2 respectively 1.5 times lower than in a cylinder, which is filled, compacted by several times a free fall and pressed twice with 10 kPa. So, to imitate physical circumstances in potplant and bedding plant production, the substrate should not be compressed so much.
A good method is filling a cylinder without artificial pressure and achieve a natural assesment by flooding from beneath.