The quality (creditworthiness) of a soil with regard to its suitability for agricultural use is determined by means of bonitur. Especially when planting new vines for the first time, a laboratory analysis of the soil must be carried out as a first measure. The EUF method is a laboratory analysis procedure (electro-ultrafiltration) for testing soil substrates for the nutrients available to plants. All main nutrients and trace elements including nitrogen (in the form of ammonium and nitrate, as well as organically bound nitrogen) can be recorded.
Soil samples are taken from 0 to 60 centimetres of the soil before the start of vegetation (February to March). The subsequent chemical determination of the water-soluble elements and compounds, as well as their concentration, is carried out using standard analysis from the extraction solution (atomic spectroscopy or spectrophotometry). The extraction of the nutrients is carried out in a unit specially developed for this procedure using heating and electricity. In a first step (fraction) the directly available nutrient is determined at 30 °Celsius, 200 volts and 15 milliamperes, and in a second step the potentially available nutrient (stock) is determined at 80 °Celsius, 400 volts and 150 milliamperes.
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Thomas Götz
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