LaMotte TL-2 Turf Lab Soil Test Kit - Manual (Page 6)

4. Use the funnel (0459) and filter paper (0465) to filter solution. Collect
the soil filtrate in a vial (0989).
5. Perform the Phosphorus test according to the procedure above.
PO TAS SIUM
1.
Use the 1 mL pipet (0354) to add 2 mL of soil filtrate to the round tube.
2. Use a second 1 mL pipet (0354) to add 2 mL of *Potassium TPB Solution
(3825). Wait 5 minutes.
3. Dilute to top line with deionized water. Cap and shake to mix.
4. Remove the cap and slowly insert the square tube with the collar. The
square tube will slide up and down through the collar and will fill with
liquid.
5. Viewing from above, adjust the square tube in the turbid solution until the
black dot on its base is obscured. Hold the round tube at the top to avoid
blocking the light.
6. Note the height of the liquid in the square tube. Record as lb/acre
potassium. To convert the results to potash (K
2
O), multiply the result by
1.2. Record as lb/acre potash.
NOTE:
Brush tubes thoroughly after each use.
NEU TRAL IZA TION OF SOIL FIL TRATE
In the Iron, Calcium and Magnesium tests, the acidity of the soil filtrate must
be neutralized before testing. This is done by adding Sodium Hydroxide, 15%
(7886) to the soil filtrate, one drop at a time, until the pH test paper (2953)
indicates that the pH is between 6.0 and 7.0.
IRON
1.
Fill test tube (0106) to the 5 mL line with soil filtrate.
2. Neutralize according to Neutralization of Soil Filtrate Instructions.
3. Add 5 drops of *Iron Reagent #1 (4450).
4. Use the 0.05 g spoon (0696) to add one measure of *Iron Reagent #2
Powder (V-4451). Cap and mix until the powder has dissolved. Wait 3
minutes for maximum color development.
5. Mix once and insert test tube into the Octa-Slide Viewer (1100). Slide the
Iron Octa-Slide Bar (3479) into the Viewer. Match sample color to a color
standard. Record as ppm iron. If the sample color falls between two
standards, take the midpoint between the two standard values as the result.
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