In order to assess soil fertility appropriately and to deduce proper amelioration measures, our partner laboratory analyses up to 118 single parameters according to the method of “Fractional Analysis” (certified according to ÖNORM S2122-1). The following chart represents the parameters and the methods of analysis.
Summarized description sheet of the “Fractional Analysis”
Water-soluble elements of a soil determine the concentration of substances within the soil solution. The soil solution is the most important medium for plant nutrition. It should hold an ideal composition of nutrients because plants just have a minor ability in selecting designated nutrients.
Organic and mineral parts possess generally negative loaded surfaces (sorption surface areas). Positively loaded particles, so-called cations like Ca++, Mg++, K+, Na+, and H+ become attached to these negative surfaces. By increasing the concentration of substances in the soil solution (e.g. fertilizing, root excretions), attached particles are suppressed from the sorption surface and become available for the plant roots (=elements are exchanged).
Plant-available elements are those elements which are provided in an accessible form for plant nutrition during the growing period. They are the sum of water-soluble and exchangeable elements.
Subsequently deliverable Elements (Reserve Fraction)
Elements in the reserve fraction / subsequently deliverable elements become accessible to plants by natural weathering processes within 10 to 15 years. For ecological and economic reasons, it may be reasonable to mobilize the existing reserve pools instead of adding fertilizers.
Analysis of the Phosphorus (P) Pools
Studies (e.g. Köster und Nieder 2007) as well as our own research shows that most of the agriculturally used soils contain enormous phosphorus reserves (up to 3000 kg/ha in 30 cm of depth). These reserves are only partly immediately available to plants. Knowing the different chemical bond types of phosphorus empowers to recommend specific activities to mobilize P and integrate P into the biologic cycle again. In this respect, we are analysing and assessing the following 5 phosphorus pools:
- Water-soluble phosphorus
- Exchangeable phosphorus
- Mineral phosphorus reserve
- Organic phosphorus reserve
- Total contents of phosphorus
Köster W., R. Nieder (2007). Wann ist eine Grunddüngung mit Phosphor, Kalium und Magnesium wirtschaftlich vertretbar? www.beratung-mal-anders.de
ÖNORM S 2122-1 (2013). Erden aus Abfällen. Teil 1: Fraktionierte Analyse – Untersuchungsmethoden.