The transmissivity of the infrared radiation through smoke layers of 9 kinds was measured for different amounts of smokes. Smoke amount was at first represented relatively by the transmissivity of the visible light. Then the relation between the transmissivity of the visible light and the actual smoke amount was investigated experimentally. The relation between smoke amount and the transmissivity of the infrared radiation was shown in fig. 6.
Finally the ratio of the infrared transmissivity of these smokes to that of fog given by Mr. Saito was calculated and the controlling power for infrared radiation of fog and these smokes was compared.

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Under the conditions such as heating at night and the sun radiating in the daytime, some micrometeorological characteristics were observed in the seedling chamber.
The results are as follows:
1) When the former condition (heating at night) was given, a circulation having the least curvature grow up in the seedling chamber. So, it will be able to get the uniform temperature by utilizing such circulation reasonably.
2) Under the later condition, temperature in the seedling chamber rose up in some parts in it. Getting any uniform temperature, it is effective to open small windows on both ends of the seedling chamber.
3) In addition, putting the both ends of the seedling chamber to southern and northern directions seems to be more effetive for uniforming temperature in the chamber.

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The statistics on sunshine duration are provided which may be of a direct use in planning various industries as well as agriculture.
The climate based on the sunshine duration, which has so far not been made clear simply by the conventional statistics on the normals, is presented by displaying as a sample the following items for Fukuoka:
(1) Normal averages, standard deviations, maxima, minima, classed durations with maximum frequency, and the rates of the maximum frequency, of total decadal sunshine.
(2) Decadal rates of occurrences with classed durations of daily sunshine.
(3) Decadal total number of occurrences (for 30 years) of varying series of days with sunshine, less than 1 hour a day (including 0 hour), more than 8.1 hours a day.

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Making use of knowledge obtained in preceding papers of the turbulent diffusion of both continuous fixed-source-type and instantaneous floating-source-type, the applications of diffusion theories to several agricultural techniques are theoretically dealt with. The dusting procedure of agricultural chemicals with the dusting machine and the extending procedure of smoke screen to prevent the frost damage to agricultural products are dealt with from the theoretical viewpoint following the continuous fixed-source-type diffusion theory. The surface distribution of concentration of chemicals from the dusting machine on the ground is expressed by the gaussian profiles and the area of the effective dusting region, whithin which the concentration is greater than a certain critical value χ_0*, is shown to be
A∞(Q/Uχ_0*)^2/(1+m),
where Q and U denote the source strength of dusting machine and the appropriate mean wind speed at the dusting outlet, respectively, and m is a number depending upon the thermal stratification of the atmospheric surface layer. From the preceding paper m is shown to be 1.5, 0.8 or 0.5 under the thermally unstable, neutral or stable conditions, respectively. The effective shading region of smoke screen is analogously discussed with the vertically integrated smoke concentration. In this case, the region does not depend upon the vertical characteristics of smoke screen and the area is shown to be in proportion to (Q²/‹v²›^1/2Uχ_z*), where ‹v²›^1/2 and χ_z* denote the lateral component of wind turbulence and a certain critical value of vertically integrated smoke concentration over which the shading is effective. The problems of diffusion area due to a battery of several smoke machines and to moving machines are discussed, too.
The aerial dusting from aircrafts of agricultural chemicals is dealt with as the floating-source-type diffusion during the time t from the release. The width l_* of effective swath is shown to be
l_*=√2/3ε^1/4t^3/4(ln3Q/√2πχ_*ε^1/2t^3/2),
where χ_* is the critical value of concentration and ε is the mean rate of turbulent energy dissipation within the height from the ground surface to the dusting aircraft. The maximum of the effective swath is obtained under the condition of t=0.477 (3Q/√2πχ_*ε^1/2)^2/3. This problem is similar to that of the smoke dissipation time and the application of smoke dissipation time as a measure to the aerial dusting procedure is discussed. The importance of micrometeorological elements, such as the mean wind velocity, the fluctuations in wind direction, and the temperature difference between two heights, are stressed, and the possibility of artificial control of diffusion phenomena through the modification of micrometeorological conditions is pointed out. Finally, the general calculation methods of air pollution are discussed only briefly.

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In Miyagi Prefecture, 1955, the rice yield was increased as much as 126 per cent of the average year yield, and the increasing rate of yield was different from each other for villages. Then we investigated these rates in areas irrigated with low temperature water. The results obtained were as follows:
(1) Several villages through out our county showed the different rates in their increasing yields. As a tendency in general, the increasing rates of rice yield in the villages obtaining good harvest in ordinary year were low, but, on the contrary, in the villages with poor harvest these rates were high and in the latter it was indicated in the figure of 30-40 per cent. Such tendency was recognized in the area irrigated with cold water, too. The larger the ratio of paddy field with cold water in each village, the higher was the increasing rate of rice yield.
(2) In the mountaneous area the climatic conditions during that summer were favorable for the growth of rice plant, and such trends were recognized strikingly on the maximum temperature of air, daily range of air temperature and a number of fine days.
(3) As an example of field observation in area with cold water we may present the data on the temperature of irrigation water in the Okura River Basin. According to those data the water temperature in that area was much warmer, so that the effect of cold water for the rice yield was much less than in Shichigashuku-mura, 1954, that is to say, in the Okura River Basin the effect of cold water disappeared in the 20 per cent of the irrigated space in the paddy field.
We might consider that the higher increasing rate of rice yield was obtained because during the summer the climatic conditions and the temperature of irrigated water were favorable for the growth of rice plant.

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Although there are three forms of drifting soil such as surface creep, saltation and suspension, a great part of them is accounted for by saltation.
Soil drifted into another by saltation stirs it up in motion and they keep gathering accelarating increase of flying soil amount as they shift leeward, until maximum capable of being carried by wind.
Soil soars up almost vertically to the ground and downs at an angle of 10°to 20°.
Around 70% of soil flying in the air proves rotating always from 200 to 800 times per second.
This rotation will prove vertical line of soil's jump. Soil grain of about 0.2mm diameter is easiest to move and in a result, as you may calculate, any of less or more diameter will naturally be not easier in movement.
The crest of the higher ridge is likely to suffer the more erosion.

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The purpose of this study was to made measurements of the extent of damage to wheat and barley plants caused by the mechanical force of wind. (1) The water requirement varies with the degree of injury to plants. (2) Wheat and barley were given exposure to wind in a wind tunnel to evaluate the extent of injury occurring at early stage of growth. The treatment was used at 13m/s and 20m/s for 2 houre. Increasing the velocity of wind and decreasing number of leaves of wheat and barley, the abrasive injuries were increased. (3) The wheat plants were subjected to cutting degree of leaf. By cutting of all leaf blade the grain yields were decreased 13-30% and heading was delayed 2 days comparing to the non-treatment.

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