LaMotte AST Series Professional Soil Test Outfits - Manual (Page 37)

PROCEDURE
1.
Use the 0.5 spoon (0698) to add 8 level measures of soil to an
extraction tube (0704).
2. Add deionized or tap water to 14 mL line. Cap and shake to mix.
3. Use the 0.5 g spoon (0698) to add 2 measures *Humus Screening
Reagent Powder (5119). If necessary, add more water to bring level
to 14 mL mark. Cap and mix vigorously for one minute.
4. Add 15 drops of Soil Flocculating Reagent (5643WT). Cap and mix
gently. Allow the soil to settle for several minutes.
5. Use filter paper (0465) and funnel (0459) to filter mixture (see How
to Use a Funnel and Filter Paper, page 10). Collect filtrate in a
second extraction tube.
6. Match sample color of the filtrate to a color standard on the Humus
Color Chart (1384). Record result. Use chart to convert result to a
value.
Humus or Organic Matter in Soil
Humus Reading 1 2 3 4 5
Agricultural Soils Low Medium High
Garden Greenhouse Soils Low Medium High
Organic Soils Low Medium High
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