A DEVICE FOR EXTRACTING CLARIFIED SOIL SOLUTIONS WITHOUT FILTER-PAPER

The design and construction of a centrifugal soil solution extracting device are described. The device can be rapidly constructed out of inexpensive, readily available materials. The unit does not require filter paper, thus avoiding the problems of filter paper contamination, breakage, and clogging. The unit disassembles easily, permitting rapid removal of the soil and easy cleaning of the parts. It is best suited for sandy soils and well-structured soils with low amounts of of 2:1 clays, but under some circumstances may prove suitable for soils with high clay contents. The unit described holds approximately 50 cm3 of soil, and can easily be modified to hold larger volumes of soil. The unit has been tested using field-moist soils, but may be modified to extract soil solutions under lower moisture tensions by using miscible and immiscible displacement techniques. A skilled technician can extract solutions at a rate of eight samples per hour using eight extraction units and a centrifuge with four cups.