The high speed shear tests using the model track shoe were tried to know the influence of the shear test speeds on shear stress-displacement curves and on shearing strength in three soils. The results obtained in these tests may be described as follows.
Track shoe sinks during tests under various vertical loads. This phenomena seems to relate to the horizontal displacement of track shoe. In general, the shear stress-horizontal displacement curves move to the left with the increase of shear test speeds and the horizontal-vertical displacement displacement curves are independent of shear test speeds. It is important result that the shearing strength is independent of shear test speeds in cohesionless soils, but it is expressed by linear function of logarithm of shear test speeds in cohesive soil.

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The influence of vertical stresses and of water content in soil on the sinkage of a model track shoe and the behaviour of a model track shoe subjected to the repeated load were studied. The results obtained are summarized as follows.
1) The relation between the sinkage and time in crawler type vehicles may be expressed by expressions (4), and (5).
2) The experimental coefficient a and b in expression (4) decrease with increasing the vertical stresses and this trend becomes significant with increase in water contents.
3) The coefficient k does not exist in higher water contents, but exists in lower water contents.
4) When the shoe is subjected to the repeated vertical stresses, the coefficient a is independent of the number of cycles and the coefficient b increases with the number of cycles. The elastic sinkage holds a certain value with increasing the cycles in the repeated stress test.

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This report is to examine the locomotive characteristics of a float type rice transplanter. The main results obtained are the followings;
(1) The driving torque of the float type rice transplanter can be obtained theoretically by equation (11). If the acceleration and the handling force are negligible, it can be obtained theoretically by equation (12).
(2) The distribution of the contact pressure of the float can be measured by plugging the subminiature pressure sensors in the bottom plate of the float (Fig. 2). The measured results are in Fig. 4 and 5.
(3) The driving torque which the float type rice transplanter needs for its locomotion in the puddling field was measured. The torque at 100% slippage as at turning was also measured (Table 1).
(4) The carried load by the float amounted to 50-65% of the total weight. This load, however, may be varied depending on the size of the float, the condition of the paddled field and so forth.
(5) The coefficient of sliding resistance of the float was measured in the puddled field. The measured value was in the range of 0.15-0.42. The coefficient of rolling resistance of the wheels was also obtained as follows;
diameter of the wheel 560mm; 0.30-0.62
diameter of the wheel 460mm; 0.32-0.68

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This study is applying the digital computer to the power sprayer design.
The algorism of power sprayer design must be standardized in the first step. The next step is to prepare a flow chart which outlines generally the design, and the problems are solved automatically by the digital computer.
In this report, the volumetric efficiency and pumping efficiency were calculated in addition to the design, using the coefficients of loss and the torque loss in the theoretical equations which were obtained from the experimental data and structural size of power sprayer.
The flow charts of basic calculation of power sprayer design are shown in Fig. 3-6. This design was programed by FORTRAN, and calculated by the digital computer TOSBAC-3400/41.
The main sizes and performance of power sprayer used as the model in this report were shown in Table 3 to be compared with the results designed by the computer.
The sufficiency of programing was recognized.

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Dynamic responces of the automatic feed rate control for the head feed type combine was simulated on the digital computer.
(1) Input and output responces of the elements, especially non-linear elements, in the combine and the control system were analysed respectively. The operations of combine and control system were simulated by connecting these elements.
(2) The threshing cylinder torque of the headfeed type combine with respect to the feed-rate was assumed as hereditary phenomenon and represented by the integral equation. Hereditary function was determined from the experiment of one sheaf threshing.
(3) The dynamic response of the servomechanism of the hydrostatic drive was analysed and the travel speed was determined. Smoothing action of the straw layer thickness and the time delay on the feeding conveyer were simulated with the moving average method and with the sliding of the dimension respectively.
(4) Calculations were done with giving the initial conditions and the field conditions of the plant density changes of step function and sinusoidal function.
(5) Hunting occured at the control of the cylinder torque sensing because of the time delay on the feeding conveyer. In case of the two input control, it is desirable to control mainly with the straw layer sensing and subsidiarily with the cylinder torque sensing.
(6) The cylinder torque was not influenced by the plant density change under 0.5m wave length, due to the smoothing action of the feeding conveyer and the hereditary of the cylinder.

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The purpose of this experiment was to investigate the performance of System of Cooling and Cold Air Drying for Rough Rice Storage by measuring the quality of rough rice during storage. Early season rice was used as experimental material. 15°C and 14.5% moisture were adopted as conditions of storage Indices used for judging the quality of rough rice were cracking, germination and free fatty acid.
The main results were as follows.
1) The times required for rough rice with the initial grain temperature of 33.3°C and 21.9% moisture content to reach the above condition were shown below respectively. In division C. (Table 1) the time required for rough rice (200Kg) to reach the above condition was 4 to 6 hours in cooling and 59 to 80 hours in drying under 15-25°C, 55-85% R. H. and 1.23m³/min/100Kg. The average drying rate per hour ranged from 0.13 to 0.09%/hr. In division I. the moisture content of rough rice (200Kg) reduced to 14.5% in 15 hours under 42-46°C, 48% R. H., 10.8m³/min/100Kg, 4 heating periods of 0.5 hour each and 3 intermittent periods of 3 hours each. The average drying rate per hour was 0.5%/hr. In division U. the moisture content of rough rice (20Kg) reduced 14.5% in 24 hours under 35°C, 70±10% R. H. and 10.8m³/min/100Kg. The average drying rate per hour was 0.3%/hr.
2) After the rough rice was dried, all of them were stored for about six months. The grain temperatures and moisture contents of rough rice during storage were 15±2°C and 15±1% in division C. J., 15±0.5°C and 14±1% in divisions I. L. and U. L., 14-32°C and 11-14% in divisions I. O. and U. O., respectively.
3) Cracking was not observed at all in any drying divisions.
4) Harmful insects did not grow in three divisions C. J., I. L. and U. L. In both I. O. and U. O. divisions, it was judged that rough rice was not suitable for eating, because some rice weevils and small weevils grew after about 56 days.
5) The initial rate of germination of rough rice was 33% in dormancy. In divisions I. O. and U. O. the dormancy of rough rice was broken completely after 30 days, but the rate of germination began to decrease after 115 days. In divisions I. L. and U. L. the dormancy of rough rice was broken after 70 days. After 152 days the rate of germination of rough rice in division I. L. showed an increasing trend, whereas in division U. L. it showed a decreasing trend. In division C. J. the dormancy breakage was increased to 85% barely after 200 days, because of the slowest breaking speed dormancy. But it was suppose that the rough rice should have the longest life, because it was confirmed that the rough rice had a germination capacity of 93% in practice.
6) Considering a possibility of nongermination state in spite of its germination capacity, we cannot necessarily conclude that the rough rice is of better quality when its rate of germination is great.
7) The authors considered that free fatty acid of rough rice during storage could be minimized by means of System of C. J.
8) As described above, it was confirmed that System of Cooling and Cold air Drying for Grain Storage was an excellent system which made drying very large bulk of rough rice possible without deteriorating it quality and storing it for a long term. Furthermore, the possibility became apparent of making use of dormancy of grains for establishment a drying and long term storage system.
C.: Cooling and Cold air drying.
C. J.: Cooling and Cold air drying and Jacketed storage.
I.: Intermittent drying.
I. L.: Intermittent drying and Low temperature storage.
I. O.: Intermittent drying and Ordinary storage.
U.: Unheated air drying.
U. L.: Unheated air drying and Low temperature storage.
U. O.: Unheated air drying and Ordinary storage.

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We studied the drying characteristics of barley grains to clarify the relationship between drying condition and drying rates or germinability.
The results were as follows:
1) It was found that the drying process of barley grains appeared to be falling-rate drying. The falling-rate drying theory was employed to determine the effect of air temperatures and initial moisture contents on drying character of barley grains. The drying rate was given by the following empirical formula as
-dM/dθ={0.0727e^{0.0788(T-T_W)-0.00417M₀}}
×{M+0.224(T-T_W)-12.39}
where M₀=initial moisture content % db
M_E=equilibrium moisture content % db
M=moisture content after a time % db
θ=time hr
T=drying bulb temperature of drying air °C
T_W=wet bulb temperature of drying air °C
A graphical comparison of calculated and observed moisture profiles is shown in Fig. 7.
The departure from the straight-line relationship at the early drying stage suggested that the drying rate of hull was very high at that stage.
2) The falling-rate of germinability by heated air drying was obtained as follow,
D=M₀{0.063e^{0.0788(T-T_W)-0.00417M₀}-0.085}
Where D=falling-rate of germinability %
To keep D less than 5%, when M equals to 30, 50, 70 and 90%, T-T_W, calculated was 19.2, 16.4, 15.2 and 15.0%, respectively.
3) In TTC tests, staining pattern of barley grains dried at higher temperatures or at higher initial moisture contents proved to be S type. (Fig. 9) These results suggested that the heat damage was inflicted on the scutellum in embryo.

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The author calculated the expense of use per unit area Y/A, consedering the expense of fuel F, labor L, and the yearly average repair R and also the economical service life N_{0 best}.
(1) F is concerned with the used area A and L is linerly concerned with the area exponentially. And then the calculate formulas were fixed (see the formula (1′) and (3)), and the coefficients were calculated (see the table 2 and 5).
(2) The value of Y/A with the yearly average used area A was calculated by dividing into the standard, best and inferior use by means of the fluctuating expences F, L and R, and by applying the value of N_{0 best} under the said each condition. The A_best, when Y/A is infinitesimal, is beyond the limits of utilizable area, but supposing it to be in this sphere, the effect of extension of A is small.
(3) When the coefficient of defrayment for the expense (1-α-δ) was 0.5, the economical used area A₀ was 2.3 ha and then the economical minimal used area A_{0 min} was 12 ha.
(4) The best Y/A in A₀ needed 29, 500 yen/ha, when (1-α-δ) was 0.5. For reduction of Y/A, the retrenchment of F, L and R was superior to the extension of A beyond A₀.

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A simple agricultural system, in which the decision maker takes observing time and weed control into account, may be considerd a stochastic multistage decision problem by introducing prediction value into the system state variables.
The aim of this paper was to formulate the simple agricultural system and to simulate the models by computer.

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In farmer's blacksmithies, pine-charcoal has been used as heating material. To understand this fact, we measured the temperature in the furnace and the mechanical and metallurgical properties of metal, using three kinds of charcoal, including pine-charcoal.
The results were as follows:
(1) The process of combustion varied with the kinds of charcoal and the combustion temperatures had effects on the forging ratio.
(2) The mechanical properties and structure of metal were independent of kinds of charcoal used.
(3) It was concluded that the use of pine-charcoal in farmer's smithies was based on the good malleability of metal resulted from the combustion temperature.

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The characteristics of a ring type roller-die wafering machine for alfalfa were studied and the following results were obtained.
1. The die rotating torque was almost coustant but the power requirements increased linearly with the increase of moisture contents of hay. The maximum value of power requirements was 2-3.5 times that of mean values.
When the moisture content was 27.5% and the die rotating speed was 50rpm, the power requirements without load, the mean power and the maximum power were 1.1, 4.3 and 12.8 horse powers, respectively.
2. When the moisture content of hay was high (50%) or low (12%), the falling shock durability, tensile strength, density of wafer and magnification of density were generally all low, and the wafers formed were of no utility. The most desirable moisture content was 27.5% within the range of moisture contents of this experiment.
3. There was a similar tendency between the falling shock durability, tensile strength and density of wafer. The magnification of density was about 24 for useful ranges.
4. The shape of wafer, the imperfections of feed auger and the shortage of die rotating power had to be improved, but it was considered that this device was useful for wafering leguminous hay such as alfalfa.
5. The fundamental or essential excellences of this type were as follows: it could work continuously, it was much smaller and lighter in shape and weight and required less power than most foreign-made machines did, it was quite suitable to our small sized farms and to climatic conditions of our country, and also it had comparatively good feeding of hay to die holes.
6. On the other hand, the defects of this type were as follows: the centre of gravity was high making the machine unstable, the vibration was somewhat intense, hay readily clogged the die holes or between die-rings resulting in ununiform discharge, torque fluctuations were great, the conservation, cleaning, overhaul, repair of the machine and discharge of remained wafer were difficult, there were some problems in the structure and strength of the die-ring covers, imperfect protection against dust of hay for faces of guide rollers and gears, and also hay had to be cut to lengths of about 30-100mm.

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