LaMotte AST Series Professional Soil Test Outfits - Manual (Page 18)

AMMONIA NITROGEN
Fertile soil will give low ammonia nitrogen readings, unless nitrogenous
fertilizer has recently been added. The rapid disappearance of ammonia
after fertilizer application indicates the ammonia has been transformed
to the more available nitrogen compounds, such as nitrate. In less fertile
forest soils ammonia is the most available form of nitrogen.
Nessler’s Reagent (*Ammonia Nitrogen Reagent #2) reacts in direct
proportion with the ammonia in the sample to form a reddish-brown
color. The resulting color is matched to a color standard to determine
the ammonia nitrogen concentration.
QUANTITY CONTENTS CODE
2 x 30 mL Ammonia Nitrogen Reagent #1 4797WT-G
2 x 30 mL *Ammonia Nitrogen Reagent #2 *4798PS-G
1 Test tube, plastic, w/cap 0106
1 Pipet, 0.5 mL, plastic 0353
1 Ammonia Nitrogen Octa-Slide Bar,
10-80 ppm
3425
*WARNING: Reagents marked with an * are considered to be potential health
hazards. To view or print a Material Safety Data Sheet (MSDS) for these
reagents go to www.lamotte.com. To obtain a printed copy, contact LaMotte by
e-mail, phone or fax.
PROCEDURE
Read Use of the Octa-Slide Viewer on page 5 before proceeding.
1.
Fill a test tube (0106) to 5.0 mL line with neutralized soil extract.
NOTE: See Neutralization of Soil Extract, page 15.
2. Add 6 drops of Ammonia Nitrogen Reagent #1 (4797). Cap and mix.
3. Use a 0.5 mL pipet (0353) to add 0.5 mL of *Ammonia Nitrogen
Reagent #2 (4798). Cap and mix. Wait 5 minutes.
4. Invert the sample once to mix. Insert test tube into the Octa-Slide
Viewer (1100). Slide the Ammonia Nitrogen Octa-Slide Bar (3425)
into viewer. Match sample color to a color standard. Record as
lb/acre Ammonia Nitrogen.
NOTE: If sample color is darker than the highest color standard,
the sample must be diluted (see Sample Dilution Techniques,
page 7) and the test repeated
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