Comparison and Inter-Calibration of Different Soil P Tests Used in the Baltic Sea Countries
In the countries of the Baltic Sea Region, different standard methods are currently applied to determine the amounts of available P in soils. Target of this knowledge report was the inter-calibration of the respective national soil P tests to enable the comparison and interpretation of the values obtained by the different methods in the future. The soil samples used for the comparison and inter-calibration of eight different soil P tests were taken in four countries and represented prevalent soil types and parent materials.
Results showed that all soil P tests applied in this study were significantly correlated with each other, however, their extraction force varied considerably. Generally, it was possible to transform data from one soil P test into another but the quality of the resulting values depended on the pair of soil tests at question. While in some cases, simple regressions already yielded a coefficient of determination >80%, in other cases the inclusion of additional soil parameters was needed to achieve this level of accuracy. In some cases, no satisfactory regression equations (i.e. with R˛ > 80%) could be produced at all.
This report on the “Comparison and inter-calibration of different soil P tests used in the Baltic Sea Countries” was prepared as part of work package 4 on manure standards of the project Baltic Manure.
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