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Procedure

In order to perform the following tests, you first will need to create soil extracts from your samples using the following procedure:

    1. Fill a tube with 7 mL of Universal Extracting Solution*.

    2. Add two grams of the soil from the sample. Cap and shake the tube for one minute.

    3. Use a piece of circular filter paper and a plastic funnel to filter the soil suspension into a second tube. (Fold the filter paper in half and then half again to form a cone which is fitted into the funnel)

a.       Use a 1mL pipet to transfer 1mL of the general soil extract to one of the larger depressions on a spot plate.

b.      Add 10 drop of Nitrate Test Reagent #1*.

c.       Use a 0.5g spoon to add one level measure of Nitrate Reagent #2*.

d.      Stir thoroughly with a clean stirring rod. Allow to stand five minutes for full color development.

e.       Match sample color with the Nitrate Nitrogen Color Chart. Record as parts per million by dividing the pounds per acre value by 2.

a. Use a transfer pipette to add 5 drops of soil extract to a large depression on a spot plate.

b.      Add one drop of Nitrite Nitrogen Test Reagent #1*.

c.       Add one drop of Nitrite Nitrogen Test Reagent #2*. Mix with a clean stirring rod.

d.      Add three drops of Nitrite Nitrogen Test Reagent #3*. Mix with a stirring rod. Wait one minute

e.       Match sample color to a color standard on the Nitrite Nitrogen Color Chart. Record as parts per million nitrite nitrogen, see color chart at bottom of page. .

f.        If a sample color matches, or is deeper than, the highest standard, repeat test on a diluted sample. Transfer one drop of soil extract to a large depression spot plate. Add four drops of *Universal Extracting Solution. Follow steps b-e. Multiply the final result by 5. Record as parts per million Nitrite Nitrogen.

a.       Use a transfer pipette to transfer four drops of the general soil extract to one of the larger depressions on a spot plate.

b.      Add one drop of *Ammonia Nitrogen Test Solution. Stir with a clean stirring rod. Allow to stand for one minute.

c.       Compare the resulting color against the Ammonia Nitrogen Color Chart. The test result is expressed in relative amounts of ammonia nitrogen from very low to very high. For approximate corresponding values in parts per million or pounds per acre see below:

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