Joint International Conference on Long-term Experiments ...

For micro-elements, EDTA+KCl 15 times diluted was applied. Instead of EDTA,
EDTE+NH4Cl at the same concentration proved to be useful to measure Na and KCl
content. For the determination of Ca content, mild solvents completed with a complexforming
substance have been employed.
MATERIAL AND METHOD
The macerate with HNO3+H2O2 was prepared according to the standard MSZ 21470-
50:1998 (For all elements). Many elements of the soil are indifferent from the point of view
of plant nutrition; however, their registration fixes the “upper point” or the maximum value
for comparing it with the data obtained with other extraction methods.
Ethylene-diamine-tetra-acetate + KCl, or EDTA according to MSZ 20135:1999, serves for
the measurement of micro-elements but it is less used in the international practice. The KCl
is an active solvent that carries a complex forming effect and keeps the micro-elements in a
dissolved status.
Ammonium-lactate, MSZ 20135:1999 or AL. The acid buffering system (pH = 3.75)
overestimates substantially the available P and Mg content of alkaline (carbonatecontaining)
soils, whereas underestimates them in acid soils.
Ammonium-chloride with EDTE (EDTE+NH4Cl) solution.
It means 0.0033 M ethylene-diamine-tetra-acetic-acid, 0.0067 M ammonia-solution and
0.0067 M ammonium chloride per 1 dm 3 .
Preparation: a 1000 cm 3 test-tube is filled with 0.96 g ethylene-diamine-tetra-acetic-acid
(selection-B) and 40 cm 3 distilled water added. Then 0.9 cm 3 25 m/m % ammonia-solution
is mixed to the selection-B until being completely dissolved (3-4 minutes).
Further 0.33 g ammonium-chloride is dissolved and filled to about 950 cm 3 with distilled
water. The pH is adjusted to 7.00 ± 0.05 with 0.01 M hydrochloric acid or ammonia
solution, if necessary, and completed until the caesura with water.
RESULTS AND DISCUSSION
For the characterisation of soil profiles, the important moment is the assessment of the Ca
and Mg profile. From the point of view of fertility, a deeply penetrating humus layer and a
thin, upper, lime-less layer are advantageous.
The Ca and Mg supply of the arable layer signalises a favourable nutritional status and
granular structure. Ca content of the soil is not only considered in the upper layer but also in
the deeper strata. Especially calciphilous plants with a large root system are affected, e.g.
alfalfa. Subsequently, 5 soil profiles are presented from the point of view of Ca content
using different solvent solutions (Table 1).
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