It is very common to observe nonlinear features in agricultural and ecological systems. For example, in tree crop production, alternate bearing is well known phenomena caused by nonlinear dynamics. Production of single tree of Citrus Unshiu trees is recognized to be driven by a mechanistic process modeled with the so-called “resource budget model”, which demonstrates phenomenon of alternate bearing. However, the term of alternative bearing is used not only for an individual tree’s production but also for total production of a large sized population of trees. In this paper, we developed noise induced uncoupled dynamics model for population alternate bearing based on Isagi’s resource budget model. Based on numerical experiments with the developed model, theoretical possibility of a substantial alternate bearing effect even in a national market was proposed.
In order to understand the impact of treadle water wheels on agricultural production in Japan, it is important to obtain precise data on the performance of parameters impacted by the use of the treadle water wheel such as the water discharge rate. The objective of this study is to clarify the basic water lifting performance of the treadle water wheel. For that, the theoretical expression of the water discharge rate is reviewed by practically measuring this rate and evaluating the water lifting rate. As a result, the water discharge rate of the treadle water wheel was practically measured under various conditions. It was clarified that the water lifting rate is lower than the previous proposed value.
We sought to develop an automatic seedling feeder compatible with a semi-automatic grafting robot for cucurbits. We focused on seedlings with a non-uniform direction of cotyledon expansion. After investigating cotyledon development guidance within a fixed range using a prior cotyledon-orienting device, we investigated guidance based on precision testing conducted using an experimental automatic stock feeder. The prior cotyledon-orienting device guided cotyledon development to the grafting robot in a suitable direction. Of the seedlings deviating by more than ±50°, 89% were corrected to within ±50°. This method has the same effectiveness as typical alignment seeding. The precision and joining and agglutination rates of automatically grafted stalks were 100%. Furthermore, 98% of grafted seedlings reached maturity. These results suggest potential real-world applications.
We studied a test method that would minimize the effects of the environmental conditions on the results of engine performance and also conducted a fair test. We clarified that differences in the atmospheric factors calculated on the basis of the dry atmospheric pressure and intake air temperature, influence the results of an engine performance test. In this study, we investigated the effects of maintaining the atmospheric factors on the engine performance and emission gases in naturally aspirated diesel engines. As a result, we clarified that the variations in the test results for the engine power, specific fuel consumption and particulate matter can be reduced by maintaining the atmospheric factors.
We have produced a prototype threshing machine, model No. 1, that is designed to protect farmers from a severe injury sustained if their hand is caught in the threshing unit of a head-feeding combine when hand feeding the machine. This was developed after surveying the requirements of farmers regarding hand feeding the machine and examining the conditions that the prospective machine should accomplish. More than 70 % of the farmers surveyed replied that they had to continue performing hand-fed threshing. We took extra care to slow down the speed of the feed-chain during hand-fed threshing. This was done by either placing a clutch inside the actuator of the feed-chain or actuating the feed-chain by hydraulic static transmission. This enables the feed-chain to be stopped before a hand caught in the machine reaches the threshing unit. We limited the height of the emergency stop switch to a maximum of 1700mm so that female and elderly workers could reach it.