LaMotte Greenhouse Soil Testing Outfit GS-01 - Manual (Page 5)

CAL CIUM AND MAG NE SIUM
The Schwarzenbach EDTA titration, used to determine calcium and
magnesium levels, involves two separate titrations. The first titration
determines the combined calcium and magnesium level, and the second
titration indicates the calcium level only. Magnesium is determined by
calculation.
QUANTITY CONTENTS CODE
30 mL Calcium-Magnesium Inhibitor 3922-G
30 mL *Calcium & Magnesium Buffer *5126-G
2 x 15 mL *CM Indicator Reagent *6522-E
250 mL Standard EDTA Reagent 5254-K
15 mL *Inhibitor Solution *9258-E
15 mL *TEA Reagent *3921-E
30 mL *Sodium Hydroxide Reagent
w/Metal Inhibitors
*4259-G
100 Calcium Hardness Indicator Tablets T-5250-
J
1 pH Hydrion Test Papers, 4.5-7.5 2953
1 Graduated Cylinder, 25 mL 0417
1 Beaker, 50 mL 0944
1 Test Tube, 5-10-15 mL, w/cap 0778
1 Direct Reading Titrator, 0 - 1000 Range 0384
*WARNING: Reagents marked with a * are considered hazardous substances.
Material Safety Data Sheets (MSDS) are supplied for these reagents. For your
safety, read label and accompanying MSDS before using.
Carefully read the LaMotte Direct Reading Titrator Instruction Manual
before performing titrations.
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SAM PLING PRO CE DURE
It is important to gather a representative soil sample to achieve
meaningful results. The following instructions will help achieve a
representative sample.
1.
Use a soil probe or similar device to collect sample.
2. Wait at least six hours after watering to sample.
3. If dry fertilizer is used, wait 5 days after application to sample. If
fertilizer is applied through a liquid injector system, wait at least 24
hours after application to sample.
4. Scrape away mulch and top c“ of soil.
5. Collect sufficient soil cores (10 - 15) to gather at least 1 pint of soil.
WHEN TO SAM PLE
Many fertilizer problems may be avoided by sampling stockpiles of soil
mixes before adding any fertilizer. Once the fertility level of the basic
soil mix is established, a suitable soil fertility program can be
established. Fertilizer should be mixed with the soil according to the soil
test results, taking into account the use of a fertilizer injection system.
For all greenhouse crops, the soil should be sampled and tested prior to
seeding or planting. No additional sampling is necessary for bedding
plants and potted plants unless a problem develops. A greenhouse
operation specializing in continuous production of one or two crops will
want to sample the soil as the crop is finishing out. This will give a
good indication of the fertility level which has been maintained.
For bench crops, the soil should be sampled every three months. This
will enable greenhouse operators to maintain good soil fertility levels
and avoid nutritional problems.
For vegetables, the soil should be sampled before fertilization or
planting. This will enable the grower to use the proper kinds and
amount of fertilizer. Sampling the soil which the crop is growing will
indicate whether adequate nutrient levels are being maintained.
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