LaMotte PHOSPHORUS IN SOIL TEST KIT ST-P - Manual (Page 2)

4. Add 6 drops of *Phosphorus Reagent #2 (5156). Cap and mix
thoroughly.
5. Add 1 *Phosphorus Test Tablet (5706A). Cap and shake until tablet
disintegrates.
6. Match sample color to a color standard on the Phosphorus Color
Chart (1312). Record as pounds per acre of Phosphorus.
NOTE: It is very important to avoid all sources of contamination during
the test procedure. Make sure the operator’s hands, test equipment, and
test area are free of fertilizer.
PHOS PHO RUS PLANT TIS SUE TEST
To determine the level of phosphorus in plant tissue a colorimetric test is
made on a tissue extract from a normal plant and compared with test
results using a tissue extract from a questionable plant. It is important to
test healthy plants as well as questionable plants as the test is most
valuable when used in a comparative manner. Select small lots of the leaf
petioles or succulent portions of the stem from the part of the plant most
noticeably affected by symptoms of abnormal nutrition. Using a clean
sharp knife or razor blade cut the plant material into fine bits of not more
than
1
8
to 1
16
inches in length and thickness. Also make a similar sample
from a healthy plant of the same crop or species.
PRO CE DURE
1.
Fill Phosphorus Tube “A” halfway to the line with the plant tissue.
2. Dilute to the line with Phosphorus Reagent #1 (5155). Cap and
shake vigorously for 5 minutes.
3. Filter the tissue extract into a clean Phosphorus Tube “B”.
4. Add 6 drops of *Phosphorus Reagent #2 (5156).
5. Add *Phosphorus Reagent #3 Tablet (5157). Cap and shake until
tablet disintegrates.
6. Compare the reaction of the healthy sample with the reaction of the
questionable sample. The healthy plant should give a light to deep
blue color.
LaMOTTE COM PANY
Helping Peo ple Solve An a lyt i cal Chal lenges SM
PO Box 329 • Chestertown • Mary land • 21620 • USA
800-344-3100 • 410-778-3100 (Out side U.S.A. • Fax 410-778-6394
Visit us on the web at www.lamotte.com
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