Change in analysis method can have far-reaching consequences
The international method for analysing soil texture provides more precise results than the Danish method. However, if the Danish authorities adopt the method it could undermine the Danish soil classification system. AGRO intends to investigate the consequences.
In Denmark we determine soil texture with an analysis method that is in accordance with the Danish AgriFish Agency. The method is cheaper and quicker than the method that is commonly used internationally. However, the Danish method does pose some problems.
As described in the article “Texture determination: Possibility for following international practice”, the Danish method can be less precise in some soil types and can also make it difficult to compare our data with data from other countries. The logical solution would seem to be that Denmark adopts the international analysis method.
Scientists from AGRO have previously recommended a change in the regulation for texture analysis so that all soils, whatever their humus content, are pre-treated with hydrogen peroxide in accordance with international practice. We also recommended the carrying out of an analysis of how great an effect a change in method would have on the existing classification of Danish soils (see page 100 in report (in Danish) ”Jordanalyser – kvalitet og anvendelse”, DCA report no. 2, December 2011).
Wheels set in motion
Action is now being taken. Department Head Erik Steen Kristensen would like to have the consequences of a change in analysis method determined and has set the wheels in motion.
- We would like to recommend the international method, but cannot just go out and do so because we are not exactly sure of the consequences. We can have a problem dealing with our existing analyses and a change can also affect the Danish soil classification system with all that it would entail, Erik Steen Kristensen points out.
Erik Steen Kristensen has therefore asked Mogens H. Greve, who is the theme coordinator for the area in AU’s contract with the Ministry of Environment and Food that is called ”Food production and the cultivated soil”, to describe an internal project. The project will investigate how we translate the old figures, which are based on the Danish analysis method, to a new scale, which is based on the international analysis method. The project will also investigate how we can deal with the soil samples that have been analysed using the “old” method.
Texture analysis measures the distribution of the size of mineral particles in the soil, i.e. clay, silt and sand. The particle size distribution forms the basis for the Danish soil classification system – the so-called JB-scale. A new method of analysis can therefore affect JB-classification.
- We will also accompany the recommendation with a description of which consequences there may be for the JB-system. It will affect the classification of some of the soils, which can have consequences in connection with rules and recommendations regarding fertilisation, irrigation and tillage, among other things, says Erik Steen Kristensen.
The project will begin in January 2016.