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Volume 20, Issue 2
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E. IMAOKA1964 Volume 20 Issue 2 Pages 41-45
Published: November 05, 1964
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe following is the explanatory summary of the influeuce of the general wind upon down slope wind in the results of some observations made, in 1961, in a valley at Hakatajima (at 34°14′N. Lat., 133°05′E. Long.) in the Inland Sea of Seto.
(1) When it is a clear night and there is no intervention of the general wind, the down slope wind blows regularly, but no systematic flowing time can be found.
(2) It may be said that, when the general wind rises under the development of the down slope wind, inversion layer grows weak and the velocity of down slope wind falls, and that the relation of the velocities of both winds is generally shown by a negative linear function. When the velocity of the general wind reaches about 1.5m/s, the down slope wind stops.
(3) It is interesting that the above-mentioned relation is also observed when the general wind blows into the rear of the down slope wind. But these facts must be examined after many observations have been made in much more lays of the land.
(4) In clear nights during the period of these observations, the general wind grew strong between 2200 and 0200 hours in many cases. Accordingly the peak of the down slope wind appeared very frequently both before midnight and after midnight.View full abstractDownload PDF (654K) -
N. TANI1964 Volume 20 Issue 2 Pages 47-50
Published: November 05, 1964
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSAt first the following conditions are assumed,
1. The diminished yield is caused by only direct wind damage.
2. The storng wind is caused by only typhoon.
3. The effect of shelter belt is only reduction of wind.
The distructive power of typhoon F is considered as the kinematic energy of wind, and the ralation of
F∝v3t
is adopted. v is the wind speed and t is the duration of the wind. Between distructive power F and damage rate r the relation
r∝Fn
is recognized, indez n changes by crop sorts and conditions. According to Dr. TSUBOI's experiments in the wind tunnel, it is known that when the crop is strong n is 1, when it is weak n becomes 1/2.
About main 30 typhoons which came to MIYAZAKI indicate that there exists the formula
F∝Vmax4
because large typhoon has high maximum wind speed Vmax and long duration t. Indeed the diminished yield of rice by typhoon is in proportion to Vmax2 (September when the rice plant is weakest period) and Vmax3 (for another month) (Fig. 2). This is easily explained by the above considerations.
Now let us consider two types of shelter belt systems, one is dense, another is loose, of which characters are shown in table 1. Fig. 3 shows the difference in yield between with and without belt system under various conditions.
Frequency distribution of typhoon in fhesouthern part of kyushu is shown in table 2. Under these conditions total gain or loss of yield for several years are shown in table 3. Dense system can protect crop against to strong wind but when strong typhoon does not come there, due to its large occupied area, the total yields decrease. We must pay attention to these facts.View full abstractDownload PDF (516K) -
N. TANI, Y. SUZUKI1964 Volume 20 Issue 2 Pages 51-54
Published: November 05, 1964
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThere is a storage for seed stocks of sweet potato in the Section of Upland farming, Kyushu Agricultural Experiment Station, it has 7m width, 9m depth, and 2.5m height, and is constructed by concrete blocks, the inner wall and ceilling are covered with heat insulators 5cm thick, and the floor is bare soil surface.
Temperatures in the storage were measured by a recording thermometer from Nov. 1962 to Jan. 1964 the results are shown in table 1. It always keeps higher about 20°C than that in the open air. The temperature at the begining of 1963 fell down, and it was difficult to keep safe store of sweet potato roots, therefore, an electric heater was needed for some time.
The difference in daily mean temperature between inside and outside Δθ is represented by
Δθ=(QR+QE+G+X)τ/c,
where QR is the respiration heat of sweet potato and it is estimated about 25cal/h.kg., QE is the heat by electric heater, G is the heat exchange to the ground, X is the residual term, τ is the time constant and c is the heat capacity of the storage.
The heat balances of this equation are shown in table 3. When temperature changes regularly such as θt=θ0+αt, the temperature difference is
Δθt-Δθ0={(QR+QE+G+X)τ/c-ατ-Δθ0}(1-e-t/τ)
The results are shown in table 4. X terms were obtained rather larger, they consist of heat by solar radiation and latent heat of evaporation or condensation, the former is estimated order of 200-300kcal/h, and the later changes by conditions, for example, when the open air temperature is rising, that is α>0, the heat which the storage recieved is spent on evaporation in the storage and X becomes smaller.View full abstractDownload PDF (557K) -
I. ABE, K. ONO, H. HIGASHIYAMA1964 Volume 20 Issue 2 Pages 55-60
Published: November 05, 1964
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSIn this report the authors studied the weather dependence of the growth of rice plants at the Pacific coast in Aomori prefecture where rice plant was suffered frequently from the cool weather in a summer season and rice production has fluctuated yearly. From the results obtained it can be expected that the decrease in rice yield due to the cool weather damage should be considerably reduced by adopting the advanced technique for cultivation.View full abstractDownload PDF (1011K) -
(1) The effect of amount of straw on soil moistureR. MURAKAMI1964 Volume 20 Issue 2 Pages 61-64
Published: November 05, 1964
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe effect of straw mulching on the water content in a surface soil layer was studied on the basis of the field measurement of soil moisture content. A plot with no straw and six plots covered by the wheat straw with the rate of 0.5, 1, 3, 6, 9 and 18kg/3.3m2 respectively, were prepared to clarify the effect of the straw mulching. The degree of protection porvided by the straw mulching against the evaporation from the soil surface has been determined and is expressed by
E=S-A, e=(S-A)/M,
where, S and A are the soil moisture content for the plots covered by straw and for the bare plot, respectively, M the amount (kg/3.3m2) of straw, and e is the soil moisture preservative efficiency of straw.
It was found that the difference in the moisture content between the plot with straw mulch and the bare plot increased inversely with decreasing the water content for the bare plot. Figure 3 shows that the difference in the water content between the bare and mulching plots is in proportion to the amount of straw, with increasing tendency that becomes gradually weak with amount of straw. As presented in Fig. 3, the maximum value in the preservative efficiency of the straw was found at the plot covered by the straw of 3kg/3.3m and was 3.0mm/kg, straw. This fact seems to indicate that most effective amount of the straw mulching for preservating the soil moisture is between 3 and 9kg/3.3m.View full abstractDownload PDF (551K) -
1964 Volume 20 Issue 2 Pages 64
Published: November 05, 1964
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (134K) -
(1) On the temperature characteritics in the silkworm rearing seat and on conditions for silkworm deseasesK. NISHIMURA, S. KOMORI1964 Volume 20 Issue 2 Pages 65-68
Published: November 05, 1964
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSIn this paper, the authors studied mainly the relationship between the microclimate in the rearing seat and the mortality of silkworms. The most dangerous condition in silkworm's culture named by “Zamure” was found to be caused by higher humidity and temperature in rearing seats. Highest temprature was at the depth of two-third from the upper surface of rearing seats of “Hakogai” with very high humidity.
The temperature in “Hakogai” was greatly affected by heat originated in the lower layer of the rearing seats. The diurnal temperature wave in the rearing room was extremely slowly propagated into the rearing seats through its surface. In summer and autumn rearing seasons, an abnormal high temperature such as it continued often till 10.00am on a next day was observed in the lowest layer of rearing seats covered by the lid. The mortality of silkworms, which were in inner part of the rearing seats, was high compared with that for the silkworms on the surface of seats. Silkworms' desease was decided to be the F-type flacheria.View full abstractDownload PDF (615K) -
1964 Volume 20 Issue 2 Pages 68a
Published: 1964
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (145K) -
1964 Volume 20 Issue 2 Pages 68b
Published: 1964
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (145K) -
S. SHIMIZU1964 Volume 20 Issue 2 Pages 69-73
Published: November 05, 1964
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (770K)
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