LaMotte SOIL POTASSIUM DEMONSTRA TION TEST KIT - Manual (Page 2)

PRO CE DURE
1. Fill a test tube (0755) to line 8 with Potassium Extracting Solution
(5707).
2. Use the 0.5 g spoon (0698) to add two measures of the soil sample to
the test tube (0755). Cap and gently shake for one minute.
3. Without removing the cap, allow the tube to stand undisturbed until
the soil particles settle and the liquid layer above the soil becomes
clear.
4. Use the pipet (0364) to fill the second test tube to line 5 with clear
solution. To accomplish this, squeeze the bulb of the pipet before
insertion in test tube containing the soil and extracting solution.
After insertion release the pressure on the bulb and “draw-up” a
portion of the clear extracting solution. Transfer to the second test
tube. Continue to transfer clear soil extract in this manner until the
level of solution is even with line 5 of the second test tube.
5. Add one Potassium Indicator Tablet (5708). Cap and shake until
dissolved. What is the color of the solution?
6. Carefully add five drops of Potassium Test Solution (5709). Cap and
mix. Did the liquid in the test tube change to a blue color similar to
the color chart? If so, a very high level of potassium is present in the
soil sample. If not, continue to add the Potassium Test Solution five
drops at a time, mixing between the addition of each 5 drops, until a
color change is noted.
NUMBER OF DROPS POTASSIUM LEVEL
10 drops or less High
10 to 20 drops Medium
20 drops or more Low
At what potassium level did the color change?
LaMOTTE COM PANY
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PO Box 329 • Chestertown • Mary land • 21620 • USA
800-344-3100 • 410-778-3100 (Out side U.S.A.) • Fax: 410-778-6394
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