[USCC] Re; soil texture testing procedures

[Will Brinton]

Craig

Its hard to believe a lab is getting incorrect results from "turbidity" unless the 
dissolved OMis very high. With the Bouyoucos method clay is something that is really 
accurate since everything else has settled out long before it.  The correct procedure 
includes proper use of a dispersant too.  It would be acceptable to use peroxide 
treatment first to destroy whatever DOM  is causing such extreme turbidity. This is 
part fo several state soil+compost specs too.

  Is this a soil lab that is seeing compost+soil for the first time?

William F Brinton
Woods End Laboratories, Inc.
290 Belgrade Road Mt Vernon ME 04352
www.solvita.com
207 293 2457 ext 17
207 322 7361 cell


compost-request at mailman.cloudnet.com wrote:

Colleagues:

Can anyone recommend soil texture testing procedures other than the
Bouyoucos Hydrometer method?  A client of mine is making up manufactured
specialty soils from their compost plus rock fines from a nearby quarry.
Apparently, this texture analysis procedure is giving false readings on Clay
content in the manufactured soil sample due to the turbidity of the water
(the finest of the rock fines) in the hydrometer, which is causing the soil
mix to not meet the landscape architect's spec of no more than 5% clay
content.

Many thanks!

Craig