LaMotte Greenhouse Soil Testing Outfit GS-02 - Manual (Page 2)

TA BLE OF CON TENTS
PAGE
Accessories ............................................................................................... 3
Use of the Octet Comparator ...................................................................3
Sampling Procedure ................................................................................ 4
Preparing the Soil Extract ....................................................................... 5
pH ........................................................................................................... 6
Nitrate Nitrogen ...................................................................................... 7
Phosphorus............................................................................................... 8
Potassium ................................................................................................ 9
Calcium and Magnesium ................................................................. 10-11
2
TI TRA TION A • CAL CIUM & MAG NE SIUM
1.
Fill test tube (0778) to 5 mL line with diluted soil extract. Dilute to
10 mL line with deionized water.
2. Add 5 drops of Calcium-Magnesium Inhibitor Reagent (3922). Swirl
to mix. Wait 5 minutes.
3. Add 5 drops of *Calcium & Magnesium Buffer (5126). Swirl to mix.
4. Add 10 drops of *CM Indicator (6522). Swirl to mix. Solution will
turn red.
5. Fill the Direct Reading Titrator (0384) with Standard EDTA Reagent
(5254). Insert Titrator tip into the center hole of the test tube cap.
6. While swirling the tube, slowly press the plunger to titrate sample
until color changes from red to blue.
7. Read the result where the plunger tip meets the scale. Multiply by
5.16. Record as Value A.
TI TRA TION B • CAL CIUM
1.
Fill test tube (0778) to 5 mL line with diluted soil extract. Dilute to
10 mL line with deionized water.
2. Add 2 drops of *Inhibitor Reagent (9258). Swirl to mix.
3. Add 2 drops of *TEA Reagent (3921). Swirl to mix.
4. Add 8 drops of *Sodium Hydroxide Reagents w/Metal Inhibitors
(4259). Swirl to mix.
5. Add 1 Calcium Hardness Indicator Tablet (T-5250). Cap and swirl
until tablet disintegrates. Solution will turn red.
6. Fill the Direct Reading Titrator (0384) with Standard EDTA Reagent
(5254). Insert Titrator tip into the center hole of the test tube cap.
7. While swirling the tube, slowly press the plunger to titrate sample
until color changes from red to blue, and does not revert to red for at
least one minute.
8. Read the result where the plunger tip meets the scale. Multiply by
5.16. Record as Value B.
FI NAL RE SULTS
Calcium Titration Value B x 0.4 = ppm Ca
Magnesium 0.24 (Value A-Value B) = ppm Mg
NOTE: To obtain results in lb/acre, multiply results by 2.1111
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