All issues
Volume 6, Issue 2
Displaying 1-14 of 14 articles from this issue
- |<
- <
- 1
- >
- >|
-
Y. FUKUSHIMA, S. IZUMI, C. NAKAMURA1951 Volume 6 Issue 2 Pages 57-60
Published: April 05, 1951
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSIn this paper we discussed division of the four districts in the running area of the Tone and Ara river, based mainly on the date of monthly precipitation during summer season.
The divisions are as follows;
A (mountains's region of Gamma prefecture)
B (mountain's region of Tochigi prefecture)
C (the plains of the mid-reaches of the Tone river)
D (Running area of the Ara river)
1) In B district, the amount of precipitation during July, August and September always exceed over that of C district in each month. There are seen much deviation of each year in C and D districts, especially that of July, is calculated 62% at the highest level in both districts. To speak of monthly variability, it ranges about 40% from the highest of July to the lowest of September.
2) The cricis mark of flood in these districts is 300mm. level, (slight higher than the average of monthly precipitation M+ Standard deviation σ)
If the precipitation rose over 400mm. we see often catastorofic flood occured.View full abstractDownload PDF (725K) -
On its regional and cyclic appearanceV. KIMURA1951 Volume 6 Issue 2 Pages 61-66
Published: April 05, 1951
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe about seventy successive years' statistics of rice production per unit area (=tan) is analysed by the least square method and picked up the bad harvest years that the ordinary harvest index=Ic is smaller than seventy five per cent in Tohoku district and its neighbours. The results are shown in table 1 and figure 1.
From above result, the bad harvest on rice in Tohoku district are (1) transitional with the latitude parallel mainly, and (2) heavier in the Pacific Coast region than in the Japan Sea Coasts. But this tendency is opposite and slighter in the southern neighbour district generally.
From the appearance of the hervest year as shown in figure 3, we may find the bad harvest years' group and the cyclic appearance of the bad harvest years.
By the stochastical small sampling calculation on the bad harvest appearance, there are obtained (1) x=17.3 years and the confidence interval=11.0-23.6 years by α=0.05 case, or 13.1-21.5 years by α=0.10 case on the width of a bad harvest group, and (2) the result as shown in table 2, on a cyclic length of the bad harvest years' appearance.View full abstractDownload PDF (1059K) -
(V) The effect of the rainfall characteristics and degree of slope on infiltrationY. MIHARA, N. TANI1951 Volume 6 Issue 2 Pages 67-70
Published: April 05, 1951
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe rapid reduction in the rate of in ake of water by bare soil as rain falls on the surface is accompanied by the formation of a thin compact layer at the surface. Previously we reported that this layer was due chiefly to the beating action of raindrops.
Now, we constructed a rain simulator, drop-size and fall-velocity of which are almost near to those of a intense rainfall, and installed small plots in which soil was put under the simulator. The effect of various combination of rain characteristics and slope upon the infiltration capacity or the rate at which water can enter the soil was studied, and following results was obtained.
a) When the soil surface is covered with a layer of absorbent cotton instead of litter or cover grass, the infiltration capacity is constant without regards to both the degree of slope and duration of a rainfall.
b) When rainfall intensity is equal but constitution of drops is not same, the infiltration capacity reduces more rapidly and gleatly in the rain which is composed of larger drops.
c) Under the same rainfall, the reduction of infiltration capacity is inversely proportionate to the increase of the degree of slope. On the surface of steep slope, the ramming action by drops is slight, and soil particles are readily washed away, so the impermeable layer can not develope at the surface.View full abstractDownload PDF (2456K) -
S. IZUMI, Y. OZAWA1951 Volume 6 Issue 2 Pages 71-74
Published: April 05, 1951
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSIn the Kanto-Tozan district we found 5 division based on the monthly average temperature during May to September at the 1°C difference each month.
The grow stages of rice differ about 5 days in each division.
There may be seen, of course, some deviation in each case from the standard owing to the economic and natural conditions but even in these cases we believe it is difficult to make payable farm managment under present social condition more than 2 grades deviation.
We found thus the existence of some definite relation between the growth stage of rice in a certain district the temperature of that period in each district.View full abstractDownload PDF (763K) -
I. TAMURA, T. KOBORI1951 Volume 6 Issue 2 Pages 75-76
Published: April 05, 1951
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (331K) -
1951 Volume 6 Issue 2 Pages 76-76,87
Published: April 05, 1951
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (856K) -
S. HARA, T. FUKAWA1951 Volume 6 Issue 2 Pages 77-79
Published: April 05, 1951
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSWe pursued the process of growth of sweet-potatoes both on the surface of the earth and underground in 1948 and in 1949 in the early-grubbing” region. In 1948 an increased yield of sweet-potatoes was recorded all over the country, in 1949 somewhat decreased yield was presumed. We studied on the relation between the growth of the sweet-potato and the meteorological conditions.
The results are as follows:
The corpulence of sweet-potatoes depends much upon the meteorological conditions in their early stage of growth; but it is much more important that low temperature and much rain make the corpulence of sweet-potatoes slow, high temperature always brings vigorous corpulence and drought advances the rate of dry-matter. These effects are recognized regardless of the stage of growth.
The increased yield in 1948 was generally due to the rice of underground temperature throughout the periods. But in the year much rain and tow underground temperature were experienced in the mid-term stage of growth. So the various growing process of saveet-potatoes based on the difference of meteorological conditions seems to be indicated hereafter.View full abstractDownload PDF (453K) -
1. The method and the apparatusK. YAMANAKA1951 Volume 6 Issue 2 Pages 80-81
Published: April 05, 1951
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSFor the purpose of measuring the environmental factors, a new method was originated by measuring the colour change of the leaf or the flower. The colour change was measured by comparing with the standard-colour-paper. Observation-colour-plates were shown in Fig 1.View full abstractDownload PDF (274K) -
II. Method by colour changeM. MATSUNO, K. YAMANAKA1951 Volume 6 Issue 2 Pages 81-82
Published: April 05, 1951
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSWe observed the colour change of Larix-leaves by standard-colour-plate on Oct. 23 and 24 1949 in Sugadaira basin, walking round on the same route as reported in the 1st paper.
Hue of Larix-leaves was 6.0 to 8.0 and the distribution of hue in the basin was accorded with the results of the 1st report as shown in Fig 1.View full abstractDownload PDF (289K) -
K. TAKEDA, K. INOUE, T. OHTA1951 Volume 6 Issue 2 Pages 83-87
Published: April 05, 1951
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSMaximum and minimum air temperatures were observed daily at a failed plantation of larix (L. Kaempferi Sarg.) from 15 to 29 October, 19948 on the SSE-slope of Mt. Fuji, the height from mean sea level being about 1454m. The observations were carried out at 9 locations situated around and in the plantation. Results obtained were found to be intimately correlated with vertical configurations of the site and the plant cover. After brief considerations regarding some probable sources which had made the plantation failed, such as soil, water, and wind conditions, the plantation was inferred to be a sort of frost-pocket.View full abstractDownload PDF (1009K) -
H. UMETANI1951 Volume 6 Issue 2 Pages 88-90
Published: April 05, 1951
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSWe observed hourly the temperature (1.2m above the ground), the evaporation and the intensity of the insolation through a coppice near Owada from Aug. 8th to 10th, 1949. The temperature distribution through the coppice depended upon the density of it and a special change was observed near the verge of it.
In the coppice the amount of the evaporation was about 1/4 and the intensity of the insolation was 1/5 as much as the outside the coppice.View full abstractDownload PDF (477K) -
Y. DAIGO, E. MARUYAMA1951 Volume 6 Issue 2 Pages 91-94
Published: April 05, 1951
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSWe planted Indian millet around the sweet-potatoes fields which were 1 are area and 3 are area, and made the micro climatic studies on the effects of these crops fence.
The results of this studies are as follows.
1) The wind velocity in the sweet potatoes fields surrounded with Indian millets, was often weeker than 50% of the wind velocity in the other open place.
The difference of the wind velocity between the surrounded places and the open place were little, when the wind velocity was very week or it was very strong to some extent.
The area of surrounded fields were smaller, the effects of crops fence on the wind velocity was more greater.
2) With the temperature, as far as about 30cm. above the earth, we found that the muximum temperature was higher and the minimum one was lower in the surrounded fields than in the open fields.
Figuring from the diurnal changes of earth temperature, we calucalated out the heat quantity theoritically that came in and out through the earth. The result made clean that the surround fields obtained more heat quantity than the open fields.
3) The amount of evaporation in the surrounded fields was less than in the open fields. As the results which we observed the amount of evaporation in September, the amount of evaporation in the surrounded field with 3 are area was 81% and that of one with 1 are area was 78% against the amount of the evaporation of the open fields.
4) The vaper tension in the surrounded field was higher in the day time, and in the night on the control lower than in the open field.View full abstractDownload PDF (667K) -
S. SATO1951 Volume 6 Issue 2 Pages 95-97
Published: April 05, 1951
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe relations between the growth and yield of rice and the thermal characteristics of the microclimate depending on the following methods of irrigation were investigated.
Plot A: with stagnant water
Plot B: without surface water
Plot C: irrigated with running water
The results are summarized asafollows.
Plot A is the highest in tempeaature, and plot C the lowest on an average. The daily range of soil-temperature is the greatest in plot B, and the smallest in plot C. The methods of irrigation influence greatly on the soil-temperature, but a little on the air-temperature above the water surface.
It semis that the yields are effected by the macroulimate as well as the microclimate.
The yields were the most in plot C, and the least in plot A in the year 1947—the climate was very hot and had ample sunshiny.
In 1948, the significant differences of yields were not seen within the above three plots.View full abstractDownload PDF (497K) -
S. SUZUKI, S. SHIGETOMI1951 Volume 6 Issue 2 Pages 98-102
Published: April 05, 1951
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe thermal diffusibility of the soil is calculated from the surface to the layer 8m deep, using the data observed in Sapporo (43°.N) and Kagoshima (32°.N). The formula is
K (thermal diffusibility)=Δθ/Δt/Δ2θ/Δz2
The results are shown in Fig 2, Fig 3 and Fig 4.
In the case of the daily variation of thermal diffusibility, its minimum retards with depth, appearing 12 hours later at the layer 20cm deep than on the surface. Also the amplitude decrease exponentially with depth.
In the case of the annual variation, it takes the gratest value at the depth 4m, presenting the largest fluctuation.
The thermal diffusibility of the soil has the initimate connection with its water content, generally increasing with the decrease of the letter, as shown in Fig 5. The curves drawn in Fig 2 and Fig 3 may therefore be regerded as representing the time variation of the reciprocal of the water content.View full abstractDownload PDF (938K)
- |<
- <
- 1
- >
- >|