PRONOVA Stelzner EC 2000, Technical Instructions

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49
GB
Na (H
2
O), overall < 100 mg/l
Na (H
2
O) for azaleas, ericas, boggy soil < 35 mg/l
Cl (H
2
O), overall < 200 mg/l
Cl (H
2
O) for azaleas, ericas, boggy soil < 100 mg/l
Plant compatibility
Free of substances which could be harmful to
plants, according to seedling test
Weed density
No more than one germinating seed or living
plant per litre of substrata.
Source: Rolf Röber/Henning Schacht, Plant Nourishment for Horticulture
Publisher: Eugen Ulmer KG, In Stuttgart-Hohenheim, Germany, Tab. 77, p. 154
6.3 Guideline values for evaluating soil test results
Floriculture plants under glass
Mg/l substra-
tum in accor-
dance with
VDLUFA nu-
trient needs*
Nitrogen (N)
Phosphate
(P
2
O
5
)
Potassium
(K
2
O)
Magnesium
(Mg)
Salt content
Salt tolerance
Indicatory
ranges
Indicatory
ranges
Indicatory
ranges
Indicatory
ranges
Indicatory
ranges
I = low 70 –140 50 – 100 100 – 200 30 – 60 500 – 1000
II = middle 140 – 280 100 – 200 200 – 400 60 – 120 1000 – 2000
III = high 280 – 420 200 – 300 400 – 600 120 – 200 2000 – 3000
Trace nutrients
Iron
(Fe)
Manganese
(Mn)
Copper
(Cu)
Boron
(B)
Zinc
(Zn)
Molybdenum
(Mo)
Optimal ranges
mg/l
10 – 50 5 – 40 3 – 10 0,5 – 1,0 1 – 5 0,1 – 2,0
*) For crops, refer to the large Table 5.5.
Phosphate and potassium
The lower values in the optimal ranges are
valid for young plants, for irrigation fertiliza-
tion and for ripening and dormancy periods.
The upper values in the optimal ranges are
valid for potted or containerized plants
during the high-growth period and for stock
(mother) plants.
When using slow-release fertilizer, only an
inexact measure of concentration (NPK)
is possible. For bedded plants, normally no
growth problems will result when the optimal
phosphate ranges are exceeded. However
for phosphorus concentrations over 800 mg/l
for potted plants and 1500 mg/ l for bedded
plants (for example, roses or gerbera), it is
possible that there is an induced scarcity of
a trace element.