Abstract
The sampler, for obtaining undisturbed cores from the waterlogged soils has been devised. It consists of the outer and inner tubes, shown in figures 1,2 and 3. The outer tube consists of three cylinders, e.g. the upper with the bar, the middle and the lower with cutting head. The sample can, which makes the inner tube, is 76.0 mm in diameter and 30.0 or 60.0mm in height (volume of 137.8 or 27.56cc). By increasing the number of the middle cylinder, we can take soil samples each depth as deep as about 24 cm. To get the core, the sampler is pushed into a soil. After being spaded from the soil, the outer cylinders are removed in order. The cans with the samples are detached one another with a thin metal blade, and covered with can lids. The lids are set by rubber bands not to miss the moisture. The implement is somewhat unsuitable for sandy soil. Of the soil core, obtained in the above way, bulk density, moisture content, aggregate state and other properties were determind. (See Tables 1,2 and figures 4,5 and 6). From the results of determination it was found that the top soils of paddy fields were caused to possess different characteristics with their depths by the cultivation and mixing before transplanting of rice seedling.
