LaMotte STH-1 User Manual

HU MUS SCREENING TEST

MODEL STH-1 • CODE 5012

The importance of the organic fraction of the soil in affecting its physical
and chemical characteristics and overall productivity is a well established
fact. The LaMotte Humus Screening Test provides a quick and reliable
means of evaluating the Humus or organic status of a soil and should
provide valuable information, when used in conjunction with the tests for
mineral elements.

QUANTITY CONTENTS CODE

50 g *Humus Screening Reagent Powder *5119-H
60 mL Soil Flocculating Reagent 5643WT-H
120 mL Deionized Water 5115PT-J
4 Test Tubes, 7 & 14 mL, w/caps 0704
2 Spoon, 0.5 g 0698
1 Filter paper, 50/pk 0465-H
1 Funnel, plastic 0459
1 Humus Color Chart 1384

*WARNING: Reagents marked with a * are considered to be potential health
hazards. To view or print a Material Safety Data Sheet (MSDS) for these
reagents see MSDS CD or www.lamotte.com. To obtain a printed copy, contact
LaMotte by email, phone or fax.

To order individual reagents or test kit components, use the specified code
number.

PRO CE DURE

1. Use the 0.5 g spoon (0698) to add eight level measures of soil to a test
tube (0704).

2. Fill extraction tube to the 14 mL line with Deionized Water or tap
water.

3. Use the 0.5 g spoon (0698) to add 2 level measures of *Humus
Screening Reagent Powder (5119) to the soil-water mixture. If
necessary, add more water to the tube to bring the level of the
solution back up to the 14 mL line.

4. Cap the tube and shake vigorously for one minute.

5. Add 15 drops of Soil Flocculating Reagent (5643). Cap and mix

gently. Allow to settle for several minutes.

6. Filter the solution into a second extraction tube as follows:
Fold a sheet of filter paper (0465) in half, forming a semi-circle. Fold
in half again to form cone. Opening the filter paper cone, fit it into
the funnel (0459) and place the tip of the funnel into an empty
extraction tube (0704). Steadying the funnel and filter paper with
one hand, slowly pour the solution from Step 5 into the filter paper
cone.

7. Hold the tube against the white area of the color chart. Compare the
clear filtrate in the second extraction tube to the Humus Color Chart
(1384).

IN TER PRE TA TION

The Humus Color Chart (1384) is labeled with values of 1, 2, 3, 4 and 5.
The results are interpreted as follows:

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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PO Box 329 • Chestertown • Mary land • 21620 • USA

800-344-3100 • 410-778-3100 (Out side U.S.A.) • Fax [phone]

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