On the pre-treatment of samples of heavy clay soil for determinations by the pressure membrane apparatus

Authors

• Reijo Heinonen Department of Agricultural Chemistry, University of Helsinki

DOI: https://doi.org/10.23986/afsci.71546

Abstract

The method of pre-treatment of soil samples should be chosen in each case according to the purpose of study, keeping in mind the slow reversibility of the wetting undergone by heavy glacial clay. In general, it is recommended that the air-dry samples ground to 2 mm should be soaked for three weeks prior to determinations by the pressure membrane apparatus. If it is desired to make direct determinations, grinding to pass 0.6 mm appears to be conducive to good wetting, in the case of topsoils.