The influence of three phases of soil upon the growth and yield of crops (corn, red clover and timothy, and barley) has been reported. Now the relation between three phases of soil and the growth of soybeans has been studied. An early variety of soybeans (Kairyoshirome) was cultivated in pot which was filled with alluvial sandy loam developed from the Ashida River which flows through Fukuyama City, Hiroshima Prefecture. Superphosphate 3g, KCI 1g, and CaCO_3 2.5g were applied. When soil moisture was regulated to 40%, 60% and 80% of water capacity of soil equivalently, three phases of soil were as follows: A (40% of water cap.) B (60% of water cap.) C (80% of water cap.) Solid phase (%) 56.3 54.9 55.4 Gaseous phase (%) 23.0 17.5 10.0 Liquid phase (%) 20.7 27.6 34.6 Porosity (%) 43.7 45.1 44.6 The growth of soybeans was effected by the change of the three phases of the soil. The growth of soybeans under C (wet) condition in the whole period was the most, B (medium) condition was next, and A (dry) condition was the least. The earlier condition A was changed to condition C, there was observed the most growth. The earlier condition B to C was changed there was also observed very good growth, while changing condition B to A showed the least growth. The results from examination of length of stems, number of branches, total weight, weight of pods, weigth of seeds, number of pods and weight of roots showed the same tendency as the results of the growth under different conditions. The content of protein under A condition was the most, B condition was next, and C condition was the least. The same results were shown under the conditions from A to C, from B to C, from C to A or B in the cultivation period.

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We carried out the investigation on the effects of much nitrogene fertilization on growth, yield and nutritive value of teosinte. Results obtained were as follows: 1. The yield of fresh matter was increased by the increasing amount of nitrogene but the rate of increase was decreased by nitrogene dressing over 45kg per 10a. 2. As regards to contents of inorganic components, N was increased and K_2O decreased, while P_2O_5 was not affected at all by the increasing amount of nitrogen. 3. Percentage and yield of D. C. P. were increased greatly, on the contrary T. D. N. was effected so much.

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The authors found that the internode length and thickness of a stolon are correlated positively with height and weight of the leaves sprouting from one end of the internode in ladino clover, and the internode length, in particular, had correlation with the shooting speed of the new leaves. Making use of these morphological characters, the authors attemped to furnish some basic data for the diagnosis of summer depression in ladino clover in the warmer region of Japan, by means of (1) tracing the growth habit of a stolon through seasons, investigating its relation to leaf growth, (2) studying the response of a stolon to some environmental factors, and (3) comparing the growth habit of a stolon in the two regions of Japan differing in climate, namely, Chiba in southern Kanto Plain and northern island of Hokkaido. Effects of cultural and environmental factors such as clipping, fertilization, temperature, and insect injury on the growth of stolons were investigated. Clipping generally shortened the internode length and thinned the stolons of several nodes developing after clipping, though varied degrees of individual response to clipping were observed. From these observations the stolons were divided into five groups as to their types of recovery in internode length. Poor fertilization, high temperature and insect damage were considered to give depressive effects on the growth of the plant to some extent, and, dry weather in summer particularly proved to slow down the shooting speed and to thin and shorten the stolons. We compared the growth habit of the stolons of ladino clover grown in our Institute in Chiba, with that grown in the northern island of Hokkaido. The stolons in the latter region was observed to survive for more than a year, while the former had only a short life span of less than a year, most of them partially dying in summer. In Hokkaido the number of the leaves which had sprouted from a stolon of the plant through seasons was about 60-70% of that of Chiba. The stolons of the plant in Chiba tended to become shorter in summer and did not recover until October, while in Hokkaido, no such tendency was observed. The problem of how to prevent the shortening of internode length and the thinning of stolons, especially the decay and death of stolons, which obstruct the healthy growth of the plant, demands an urgent attention in the efforts of overcoming the summer depression and the short life span of ladino clover in the warmer region of Japan.

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1) In order to research the effects of soil moisture on the growth, yields and their seasonal changes, ladino clover was sown in spring in the pots. Ladino clover was grown under three soil moisture levels, that is, over soil moisture plot (to keep the water table at soil surface), high soil moisture plot (to keep the water table at the depth of 20cm. under soil surface) and low soil moisture plot (up-land field condition). This investigation was conducted in the seeding year. 2) The growing process in plant height on low soil moisture plot presented the Summer Depressive Growth, as it is called, and closely related with precipitation and temperature (Table 1, 2. Fig. 1, 2). The high temperature (till 28.2-28.6℃ in average temperature every five days in this test), did not cause the growing rate in plant height on over soil moisture and high soil moisture plots to decline in 10 days after cutting (Fig. 1). From August onward, ladino clover on the three plots grew mostly in its plant height for 10 days after cutting, and it had less further growth for 10 days after that (Fig. 1, 2). 3) High soil moisture plot produced the highest yields (fresh forage yields) of the three plots. The yields of other two plots considerably decreased and there was no wide difference between them (Table 3). But there were the differences of seasonal distribution of yields among three plots. Describing seasonal changes of yields on the point of view of yields a day, over soil moisture plot produced high yields in early summer and low yields in spring and autumn. High soil moisture plot produced high yields in spring and decreased its yields after that. Low soil moisture plot produced high yields in spring and presented Summer Depressive Growth in summer, but recovering its growth, it produced relatively high yields in autumn again (Fig. 3). 4) There was high correlation (+0.871^<***>) between plant height at cutting and yields (Fig. 4). 5) The seasonal changes of dry matter ratio of over soil moisture and high soil moisture plots were rather little, but that of low soil moisture plot was very variable and the dry matter ratio of this plot showed twice as much as those of other two plots in August and September (Table 4). 6) Arranging in order of dry root weight at depth of 0-20cm. under soil surface, as follows: Low soil moisture plot>High soil moisture plot>Over soil moisture plot (Table 5). Therefore, as the soil moisture became lower the dry root weight increased. The rate of dry root weight at depth of 0-10cm. under soil surface was 70-80%.

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