PRONOVA Stelzner EC 2000, Технические инструкции

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52
GB
This method – the determination of available
nitrogen with nitrate measurement rods
using the Schlaghecken/Neustadt-Weins-
traße process – provides an additional me-
chanism for quickly analyzing the nitrate-ni-
trogen concentration in soils and substrata.
6.5 Nitrogen quick test, soil sample
Outdoor, field-grown mineral soils:
sand, loam, loess, Garden soils
Representative soil sample
Fill a small vessel (such as a cup) with 100
g soil and weigh the soil. Then mix in 100
ml distilled water or nitrate-free tap water.
(Check the tap water by dipping in the
measuring rod; the tap water should have
less than 10 mg NO
3
.) Mix until smooth and
free of clumps. A double-folded circular filter
(for example, a funnel-shaped coffee filter) is
then dipped into the soil solution.
A clear soil solution then seeps into the filter
funnel within a few minutes. A nitrate rod is
then dipped into this filtered soil solution for
about one second. After waiting one minute,
the degree of discolouration on this rod is the
compared to the colour scale on the contai-
ner.
Rod value
mg NO
3
/l
mg nitrate per litre
equates to a soil value of
kg N/ha
kg nitrogen per ha
In 30 cm depth, or in the measured soil layer
Substrata, cultivated soils and boggy soils
Composts – potting soils
Representative substratum sample
Heap the substratum sample into a 100-ml
beaker, shake it down three times and then
level off to 100 ml.
Fill the substratum sample into a beaker
together with 442.5 ml of distilled water or
nitrate-free tap water. Mix the substratum
sample.
Then dip a double-folded circular filter (for
example, a funnel-shaped coffee filter) into
the substratum solution. A clear soil solution
then seeps into the filter funnel within a few
minutes.
Dip a nitrate rod into this filtered substrate
solution for about one second. After waiting
one minute, the degree of discolouration on
this rod is then compared to the colour scale
on the container.
Rod value
mg NO
3
/l
mg nitrate per litre
corresponds to substrate value
g N / cbm
grams of nitrogen per cbm
x 3 = kg / ha per soil layer