Studies on the Effects of Soil Physical Conditions on the Growth and Yield of Crop Plants : V. Effects of Composition of soil air on the growth of crop plants.

[摘要] When the O2 concentration in soil air decreased, the growth of crops was checked, but the effects were different according to the kinds of crops. In these studies the authors investigated the relationship between the N gas and O2 concentration in soil air and the growth of crops when it was cultivated in Wagner's pot. Sixteen kinds of crops were tested. The results obtained may be summarized as follows. Experiment 1 : Chiefly winter crops were tested. In examining the effects of the decrease of O2 concentration on the growth of crops, it was found that the growth of common vetch was significantly affected by the decrease of O2 concentration in soil air, and that the growth of oats was next to it. The growth of alfalfa, barly and wheat was found to make little differece from that of the standard treatment, and the growth of Italian ryegrass was somewhat better on the treatment where N gas was injected. Experiment 2 : Summer crops were tested. In examining the effects in question, it was found that the growth of peanut was significantly affected by the decrease of O2 concentration in soil air, and that the growth of sweet potato, maize and cucumber was also checked, whereas the growth of barnyard millet was somewhat better on the treatment where N gas was injected. Experiment 3 : The growth of every crop tested-upland rice, sorghum, soybean, Chinese cabbage and Japanese radish were checked by the decrease of O2 concentration in soil air. Above all, the growth of soybean and sorghum was inferior. Thus the effects which the decrease of O2 concentration in soil air had on the growth of crops were different depending on the kinds of crops. The effects in question were also different from one part of crops to another. For instance, in the case of sweet potato and Japanese radish the thickening of root aimed at a harvest was liable to be checked much more than any other part.

[学科分类] 农业科学（综合）