In order to establish an environment-friendly agricultural production system, we developed a method to estimate the optimal area rate of a farm that applies block crop rotation, so that self-sufficiency of bio-diesel fuel could be achieved, using genetic algorithm. The method derives the area rate which obtains a high-profit produce by meeting 4 conditions which are the status in which continuous cropping may occur and draw on area rate of creating a profitable agricultural produce. The results of applying the developed method on a model farm in the region of Tokachi, showed that different area rates could achieve equivalent level of profit which indicated the efficiency of the developed method.

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Recently, the decrease in number and the aging of agricultural workers have become significant problems. Therefore, the need for automated agricultural vehicles is increasing. This paper provides a control method for an agricultural crawler vehicle. It also provides a self-localization method using Radio Frequency (RF) tags, which measure the distance among nodes using radio waves to identify the accurate position of the vehicle inexpensively. We conducted an experiment to confirm the applicability of the proposed method in real-field conditions. As a result, the lateral error was±0.3 m while moving in a straight line using RF tags. We also conducted an experiment using Real Time Kinematic GPS to test our control method. This resulted in a lateral error of ±0.1 m while moving in a straight line.

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A panel is an essential analytical tool in sensory evaluation of food. In this study, the effect of variances in region (Sapporo, Tokyo and Osaka) and ages of panelists on rice sensory evaluation were investigated. The effect of number of panelists on rice sensory evaluation was also investigated using untrained consumer panels.
Variance in regions of panel groups had no effect on sensory evaluation. Variance in ages of panel groups had little effect on sensory evaluation, but some fluctuations by variances in ages might exist in sensory evaluation. It was found that a high level of accuracy could be obtained when more than 40 untrained panelists evaluated eating quality in a rice sensory test.

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We have developed a potato haulm remover with a mechanism that pulls out and shreds both the haulm and subterranean stolons. This machine is a self-propelled type that processes two ridges at a time, and is installed with a pair of sponge-coated lifting belts to grip and pull out the haulms and stolons. The design currently includes two plates to re-earth up the ridges and thus re-bury any loosened potatoes. This machine accuracy is 97-99%. The rate of unearthed potatoes is less than 1%. The machine travels at 1.1m/s and is capable of processing about 50a/h at a work efficiency of about 90%. Fields processed with our machine for pulling up potato haulm, rather than simple shredding, contained fewer stolons. Our results showed that stolon removal got a harvesting efficiency 40% better than only shredding the potato haulm.

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Composting processes capable of reducing the amount of grass silage contaminated by radioactive cesium were examined to decrease the workload for temporary storage or the advanced treatment for contaminated silage. In the case of composting with vacuum-type aeration, the temperature and pH in the early stage of composting were low. However, these increased gradually by the middle stage so that water was added to the contaminated silage to prevent it from being excessively dried. 53-69% of organic matter was decomposed during composting and 17MJ/kgDM of higher heating value (5.5-11MJ/kgDM of estimated lower heating value) was found in the composts. Radioactive cesium concentrations of the exhaust gases from composting and of the surrounding atmosphere were lower than the detection limit.

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The application of dibble fertilizers has been considered as a starter fertilizer application technique to improve the growth uniformity of winter lettuce. This paper describes the development of an automated dibble fertilizer applicator mounted on a commercial semiautomatic lettuce transplanter (Chidorisan) and examines whether the device could automatically deliver a precise amount of slow-releasing coated granular fertilizer into a lettuce transplanting hole without negative effects on the transplanting operation. Two volumetric metering devices with readily adjustable metering rates were designed and tested with metering volumes of 2ml to 7ml and metering speeds of 31, 47 and 70 rpm. Laboratory test results indicated that the applicator could offer both precision metering and application uniformity, which were evaluated using the coefficient of variation (CV) of the discharged amounts of fertilizer. The CV values for the metering devices ranged from 0.9% to 5.3%, whereas the overall CV values of the applicator were less than 7%. In addition, in a functional field test, the applicator was successfully operated in conjunction with practical lettuce transplantation; it completely delivered approximately 3.6g of a granular fertilizer into each transplanting hole.

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