1) The discharging ability of seeding machine for soybean which was on the market was studied on the opening diameter, the peripheral velocity and the pitch of seed holes, then the optimum conditions for accurate seeding were clarified.
2) According with the above results, the seeding machine with the declining large diameter cell was developed.
3) The developed seeding machine is able to have a high accuracy of seeding under the 0.7m/s working speed and a capability of speed up to 1.7 times of the machine which is on the market.
4) In the field condition, the seeding accuracy of the developed machine was investigated about the variation of the seeding interval, the seeding depth and the linearity of seeding row. The variation of them was statistically small when the clod breaking ratio was higher. But it was not clear on the working speed.
5) In order to get over 80% of the plant standing ratio, the ratio of clod breaking was required over 80% and the maximum limit of working speed was 0.9m/s under the soil condition with high clod breaking ratio.

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In order to make clear the working activity of furrow openers and the using way, the three kinds of furrow openers were tested and the shape of groove opened by them was investigated. The results were as follows.
1) The groove by the single disc opener gave the same working depth as set and it is adapted for grooving deep ditch.
2) The double disc opener can make the symmetric groove for seed. It is adaptable to make shallow ditch, because the width of groove becomes wider and the soil movement is larger with increasing the working depth of disc.
3) The chisel opener makes a symmetric groove for seed bed. The groove width becomes larger with increasing the working depth of disc. The effectivity of this opener was between the single disc and double disc furrow opener.

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The purpose of this paper aim to develop the machine being capable to break subsoil in order to prevent the soil from hardening and to accelerate the transport of water and air in the soil.
The rotary tiller and subsoil breaker with a chisel type subsoiler is fabricated, and is composed of a rotary tiller with small blades and a chisel type subsoiler being able to break subsoil in advance and forced to bring the rotary tiller portion smoothly into deeper subsoil.
This paper describes the field performance such as the shape, the soil hardness, the pulverization and displacement of soil disturbed by the rotary tiller and subsoil breaker with a chisel type subsoiler as influenced by the rotational speed of the rotary tiller.
As a results, this machine was able to break the soil from 0.2m to 0.3m depth and from 0.2m to 0.3m width. The diagram of soil hardness indicated that the area of influenced soil was 0.45m depth. The sieve separate test indicated that the higher rotational speed of the rotary tiller made the rotary pitch smaller and pulverized the soil smaller and made clod size smaller.
The higher rotational speed of the rotary tiller transported the soil farther away.

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The soil-overturning properties is an important matter in the working results by rotary tillage, but the mesuring method is not still established in Japan. The purpose of this study is to obtain establishment of the mesuring method and the accurate ratio of soil displacement by rotary tillage. This paper deals with two methods calcurating the ratio of soil displacement.
In this experiment, we adopted the method to use the soil mixed kalium chloride (KCI), as electrical conductivity and concentration of solution of KCI were in proportion to each other. After the electrical conductivity of the soil which mixed two level's soils differing in electrical conductivity was mesured, we discussed on a hypothetical equation to calculate the electrical conductivity of the mixed soils. The deviation between mesured electrical conductivity and calculated one showed the range of -3.4-2.3%. However it is assumed that this degree of errors are practically admitted.
From application of the hypothetical equation, the two methods (simultaneous equations of three unknowns and conditional inequality) to obtain the ratio of soil displacement were derived. Mesuring the electrical conductivity of soils which were picked before and after rotary tillage, we can easily estimate by these methods the each ratio that a soil layer before tillage moved to the three layers after tillage.
The method by simultaneous equations of three unknowns must perform the experiment of three plots in which the mixture soil of KCI was put at each layer before rotary tillage. Moreover, this method needs to make the uniform conditions of the three experimental plots.
In case of the method by conditional inequality, the ratio of soil displacement is calculated with a certain range. Therefore if this range increases, the estimating inequality become useless. However, increasing the electrical conductivity of mixture soil of KCI, it is possible to decrease the range within 1%.

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Survey was conducted with various methods to grasp some problems on the worker's health and the labor involved in the farm work of welsh-onion cultivation. The surveyed area was located in Menuma, Saitama.
The result was that the labor requirement for the manual planting operation is too much. But there is a much greater problem on the health management. In addition, as a result of the CMI survey and the audiometry, the hearing problem of workers caused by the use of welsh-onion peeling machine was pointed out as another problem.
1. Health Management
On the health condition of workers in the survey area, abnormal blood pressure, excess grease in blood, corpulence and hearing problem are remarkable.
It is necessary to know and cope with several factors in human life environment, which affect on the variation of blood pressure. The examples are as follows: to avoid spiritual stress; to avoid exposure to coldness; to avoid taking a hot bath; not to eat and drink excessively; not to eat too much salty foods. It is thought that the reason of high blood pressure associated with dietary life in this area is the too much eating of salted salmon at lunch time. This is due to the most serious factor of not having enough time to prepare lunch. Nowadays, a song, ‘IEJI’ in Japanese title, locally called ‘Ichi Ichi San Maru (tone at 11:30am) Campaign’ is broadcasted at 11:30am in the area, and it is gradually becoming effective. Thus, it would be secure to have enough time for preparing lunch.
Against corpulence, it is important to diet and exercise, especially to decrease sugariness and grease in dietary life, however, workers in this surveyed area take soft drinks, sweet cakes and cracker at tea break during farm activity. This point should be reconsidered.
2. Protection against Hearing Problem
The protection against hearing problem is to decrease the noise at its source, which is the currently being used machine, the welsh-onion peeling machine. The noise, whose frequency is in high frequency region, is made when the onion is peeled off by compressed air from the machine. Some measurements to decrease this noise would be reported in another report.
It is also effective for protection against hearing problem of the workers to use protection devises such as an ear cork and an ear muff. As mentioned before, the frequency of this noise is so high that these two devises, the ear cork and the muff, could be recommended to be used because they cut off the high frequency sound.

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The survey was conducted to study the influence of welsh-onion peeling machine on human health. The surveyed area was located in Kogane, Matudoshi, Chiba. The survey has two main points; 1) health condition of almost farmers using peeling machine in this area, 2) life and health condition in a day (during 24hr) of typical farmer using peeling machine in this area, - his life condition, the noise level that he suffered from peeling machine, his hearing power and the degree of his fatigue with work.
The results are as follows;
1) The users of machine were suffered from excess grease in blood, corpulence, anemia, liver trouble and abnormal blood pressure. This finding is in agreement with the result of 1st report. Of the suffered users, 24.7% need to be re-examined, and 50.6% should receive simple treatments, Based on the CMI survey methods, 30% were suffered from nervous disease.
The causes for anemia and corpulence were an unbalanced diet and eating excess sweet snack.
About 40.0% had hearing problem, particularly for 4000Hz frequency. Most of them had the problem for the sense of equilibrium. About 1% reduced their hearing power during 3 years.
The use of ear-plug or ear-muff produce stress.
2) The subject was using peeling machine for about 4.5hr in a day. Its machine produced intermittent noise and the noise level was above 100dB (A). The total time that he was exposed to the noise (above 100dB (A)) was about 1.5hr.
The noise level in the 40m distant place from its machine was about 60dB (A).
His fatigue condition didn't almost change during the day.

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In this paper, We investigated an effect of planting date on growth and seed yield of barley, soybean and corn (Zea mays L.) under no-tillage condition.
1) The effects of planting date on growth and seed yield were significant in the three crops, so we applied the second order regression equations with the maximum values between planting date and seed yield to these crops.
2) The significant differences at 1% error level between conventional tillage (CT) and no-tillage (NT) were not observed in seed yield of the three crops.
3) In the measurement of combustion heat related to the component of crop body, the differences between CT and NT were not clear. The clear differences among the three crops were not observed in leaf and stem, but in seed.

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