LaMotte PHOSPHORUS MODULE AM-31 - Manual (Page 2)

PRO CE DURE
NOTE: This test is very sensitive to contamination. The work area,
materials and hands should be clean. Avoid exposure to fertilizer dust.
1.
Fill a test tube (0755) to line 7 with *Universal Extracting Solution
(5173).
2. Use the 0.5 g spoon (0698) to add four level measures of soil. Cap
tube and shake for one minute.
NOTE:
When adding samples with high concentrations of
carbonates to *Universal Extracting Solution (5173), swirl tube to
mix for 30 seconds before capping to allow gases to escape.
3. Fold a piece of filter paper (0465) in half. Fold in half again. Gently
push corners together to form a cone. Place cone in funnel (0459).
4. Place funnel in clean filtrate tube (0749) and filter suspension
through the filter paper. The clear solution is the extract used in the
test.
5. Fill the Phosphorus “B” Tube (0244) to the mark with the soil
extract.
6. Add 6 drops of *Phosphorus Reagent #2 (5156) Swirl to mix.
7. Add one *Phosphorus Test Tablet (5706A). Cap and swirl until the
tablet disintegrates.
8. Remove cap. Hold tube a“ above the white area of the Phosphorus
Color Chart (1312). Looking down through the solution, match
sample color to a color standard. Record as lbs/acre phosphorus. The
color comparison should be done in natural light.
NOTE:
Do not allow the solution to stand for more than 10 minutes
before making the color comparison.
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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