Earth Systems Science, Inc.

Greg, I can't find a description of this in the manual. Is it there? If not, the formula was:
1minute= sand
1 hour=silt
24 hrs =clay

Is that correct?

Here it is

No, We were trying to keep things simple for the training. What you have in the Habitat Steward ESSI package is the basic lesson. I did an advanced lesson for the EcoAcademy folks as a follow-on exercise as a demo.

But since you asked, before you get to the sedimentation bottle step, you thorough dry the soil sample---spread thin on newspaper in the sun for a day or so. I usually know it is dry when it ''jumps'' on the newspaper when I pick it up and shake it---you can hear it ''rattle'' on the paper.

Lay it down on a flat surface, soil sample spread thin, again. Put another layer of newspaper over it and then crush the soil sample (I use an old rolling pin or an old piece of pipe or empty bottle). Then pour it in the sedimentation bottle.

Add 1 table spoon of powder dish detergent (non-sudsing). Add water (about 3/4 full to start) shake vigorously to mix everything thoroughly (be sure no soil is clinging to the bottom of the bottle). Then top of the bottle with water, continue to shake---

then let the settling begin:
1-2 minute= sand
1-2 hour=silt
1-2 days (24-48) hrs =clay

Measure the thickness of each layer; measure the total thickness of all layers together. Divide each layer by the total to get the % sand, silt, clay.

Then you need the soil texture triangle (print one out from http://www.uwsp.edu/geo/faculty/ritter/images/biosphere/soils/texture_triangle_large_2.jpg

Locate the % sand, silt, clay on the appropriate scale--then read the intercept point in the triangle to get the soil texture classification. The ideal is ''loam''.

OK, now you are free to test the soils of the world! (ok, maybe not quite, but certainly you can do this at home in your own yard for practice).

Good luck and may you have many hours of discovery, enjoyment, and enlightenment.