LaMotte DCL-20 Colorimeter - Manual (Page 24)

PHOSPHORUS CONCENTRATION CHART
%T RANGE POUNDS PER ACRE
81-100% Very Low 0-14 lbs/acre
61-80% Low 16-34 lbs/acre
39-60% Medium 35-67 lbs/acre
0-38% High Over 70 lbs/acre
PHOS PHO RUS IN AL KALINE SOILS
A special extraction procedure is used for determining the available phosphorus content of Western U.S. alkaline soils
where the pH value is above 7.0.
EXTRACTION PROCEDURE
1. Use the 1 mL pipet (0354) to add 1 mL of the *Special NF Extracting Solution (6362) to the graduated vial (0989)
then add deionized water to the graduation.
2. Add 3 one gram measures of soil using the 1 g spoon (0697) to the extracting solution in the vial.
3. Cap the vial and shake for a period of 5 minutes.
4. Filter using the funnel (0459) and filter paper (0463). Collect all of the filtrate.
5. Perform the Phosphorus test according to the Phosphorus procedure given above.
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1985-01 • 10/01