Risto Rikala , Juha Heiskanen

Turpeen puristenesteen sähkönjohtavuuden riippuvuus vesipitoisuudesta

Rikala R., Heiskanen J. Turpeen puristenesteen sähkönjohtavuuden riippuvuus vesipitoisuudesta.

Tiivistelmä

The relationship between electrical conductivity (EC) of press-water extract and water content (WC) of peat growth medium at desorption was studied. A simple time-domain reflectometer (TDR), traditional laboratory conductivity meter and gravimetric weighing were used to measure EC and WC. The relationship between EC values measured with a laboratory conductivity meter from press-water extract and those measured with TDR directly from peat medium was curvilinear. The relationship between WC of peat measured with TDR and that determined gravimetrically, although nearly linear, was slightly sigmoidal. Empirical curve between EC values and WC values measured with TDR was close to the theoretical curve, which was calculated on the basis of increase in ion concentration at desorption. Transformed EC values of press-water extract were higher than the theoretically calculated values. For comparison of EC values measured from press-water extracts in various water contents, transforming coefficients were derived. Key words: nutrient monitoring, fertilization, TDR

Avainsanat
fertilization; nutrient monitoring; TDR

Vastaanotettu 31.10.2017 Julkaistu 1.1.1997

Katselukerrat 1414

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