To assess soil fertility appropriately and also to deduce proper melioration activities our partner laboratory analyses up to 118 single parameters with the method of “Fractional Analysis” (ÖNORM S2122-1). The following chart represents the parameters and the methods of analysis.
Concluding display of analytics in “Fractional Analysis”
Water-soluble elements of a soil determine the concentration of substances in 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 have (generally negative) loaded surfaces (sorption surface areas) and attach to positively loaded parts, so called cations like Ca++, Mg++, K+, Na+, H+. By increasing the concentration of substances in the soil solution (e.g. fertilizing, root excretions) attached parts are suppressed and become available for the roots (=parts are exchanged).
Plant available elements are those elements which are accessible to plants during a growing season. They are the sum of water-soluble and exchangeable elements.
Subsequent deliverable Elements (Reserve Fraction)
Elements in the reserve fraction / subsequent deliverable elements become accessible to plants by natural weathering processes within 10 to 15 years. For ecological and economic reasons it is useful to mobilize existing reserve pools of the fields and sites instead of adding fertilizers.
Analysis of the Phosphorus (P) Pools
Studies (e.g. Köster und Nieder 2007) as well as own research show that most of the agricultural used soils have got enormous reserves of Phosphorus (up to 3000 kg/ha and 30 cm of depth). These reserves are only in parts instantly plant available. Knowing the different bond types empowers to recommend specific activities to mobilize P and integrate P into the biologic cycle again.
In the light of that we are analyzing and assessing the following 5 P pools:
- Water-soluble Phosphorus
- Exchangeable Phosphorus
- Mineral Phosphorus Reserve Pool
- Organic Phosphorus Reserve Pool
- 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.