抄録
The intensity of the toxicity symptoms due to salinization was found significantly greater in the plants under anaerobic conditions than under aerobic conditions when the plant was grown at the level of a sline concentration critical for its growth, while at higher levels, the difference was not so remarkable. The similar relation was indicated by the reduction in the root and top growth, in hydration ratio or in the leaf number. Sodium accumulation in leaf blades was lower under anaerobic conditions, the fact being particularly distinct at the critical concentration. Other elements decreased generally in the plants treated by saline solution under aerobic conditions, while under anaerobic conditions such relation was not evident. On polder fields, wheat crops, when it was alternated with rice, gave extremely small yields compared with that of upland culture of the same crop, and the length and width of leaf and size of stoma on top leaves of the plant in the former case were remarkably reduced, while the number of stomata increased. The porosity of the upper layer soil on the fields after rice cropping was distinctly smaller than that on the other fields. So far as the present experiment is concerned, it might be suspected that the toxicity symptoms of salinization should be intensified by anaerobic conditions around the roots.
