A NEW SAMPLER FOR EXTRACTING UNDISTURBED SURFACE PEAT CORES FOR GROWTH POT EXPERIMENTS

The sampler extracts uncompressed cores of 13.3 cm in diameter, up to 70 cm long, from the surface layers of peat. It has two close-fitting concentric cylindrical tubes, the outer one acting as a cutter and the inner one as a collector. As the outer tube is introduced by rotation into the peat, the cut core is collected in the inner tube which is m aintained in a fixed position during the rotation phase and then pushe d down stepwise. This limits friction between the peat core and the wa ll of the corer and prevents compression or distortion of the peat. Th ese problems are also reduced by means of three skew cutters allowing the peat to be supported during the slicing action. Air can penetrate between the tubes to the lower end of the core, suppressing any suctio n effect during withdrawal. The sampler has been tested and has worked satisfactorily in many different peat types.