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| 1. |
Place
0.5 g of air-dry soil into a 250-mL beaker. |
| 2. |
Add
5 mL of Potassium dichromate solution and swirl gently to mix
before adding acid. |
| 3. |
Add
10 ml concentrated Sulfuric acid and immediately swirl for 5-10
seconds. |
| 4. |
Allow
the mixture to stand for 10 minutes then add 50 mL of distilled
water and mix. |
| 5. |
Allow
the mixture to stand one hour and then centrifuge for 5 minutes
and let the solution stand overnight. |
| 6. |
Transfer
a potion of the clear solution to a colorimetric vial. |
| 7. |
Read
the color at 610 milli-micron wave length with the distilled
water set to give 100% transmittance. Then ,determine the
organic matter content (%) using a spreadsheet system. |
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