Spade diagnosis
The spade diagnosis is a method developed by Johannes Görbing around 1930 to determine the soil structure or soil fertility . In the 1980s it was re-established in agricultural practice through the work of Gerhardt Preuschen and Hampl.
execution
Spade diagnosis involves pressing a spade with a sharp, flat blade vertically into the ground. In order to include the transition between the top crumb and the ground, the spade must have a length of 30 cm. Initial conclusions about the condition of the soil can already be drawn from the resistance when it is pushed in.
Then you dig a small trench with another spade parallel to the spade blade of the flat spade with a perpendicular wall towards the flat spade. At right angles to the flat spade blade, two slots are made at a lateral distance of around 10 cm from the edges of the flat spade. The soil profile block to be examined is then removed with the flat spade. This is examined in a horizontal position for the condition of the structure (loose, medium, firm, possibly existing horizons ), soil moisture and parameters such as root growth.
The spade method allows the structural condition of a soil to be assessed with little effort in terms of the size and structure of the fragments and soil aggregates, as well as soil compaction , rooting and moisture. It serves as a decision-making aid for practical management measures. If necessary, a further spade test can be carried out in the subsoil by removing the already examined topsoil layer for further diagnosis.
Extension of the spade method
The Extended Spade Diagnosis (ESD) developed by Andrea Beste in cooperation with the Ecological Soil Processing (PÖB) project as part of a dissertation at the Justus-Liebig University in Gießen is a method for scientific soil assessment. A structural rating and a simple test for the water stability of the floor aggregates were newly developed for the combination of ESD methods . The greatest advantage of the methodology - especially the structural rating - is that it can also be carried out by the farmer himself.
At the EU level, guidelines for the recommendation of soil assessment methods are being planned as part of the Soil Conservation and Protection in Europe (SCAPE) project, which will facilitate and standardize the recording of soil data. A guideline for further developed spade diagnosis as a simple, practical method is in preparation.
literature
- Gerhardt Preuschen: Agriculture according to ecological principles . 2nd edition, Verlag CF Müller, Heidelberg 1994, ISBN 3-7880-9873-2 , pp. 75-116
- Gerhardt Preuschen: A Guide to Spade Diagnosis . Special edition of the journal Ökologie und Landbau, 5th edition, Ecology and Agriculture Foundation, Bad Dürkheim 1990