In this study, we describe the effect on composting process after addition of sodium hydroxide, manure compost, and spent mushroom compost to grass silage, for efficient reduction of the amount of radiocesium in contaminated silage by promoting fermentation. For this, we used 60-L vessels for 10 weeks. The degree of decomposition of grass silage was observed to be more than 60% of that of dry matter, regardless of the additives. Moreover, the differences of decrease in fiber and fatty acid were less between types of additive. Contrarily, pH, ammonium nitrogen, and germination rate differed depending on the additives. Further, during germination, significant growth inhibition was observed without compost addition presumably, because of the high ammonia nitrogen concentration.

This is a study to evaluate the economic effects and environmental impacts of biofuel self-sufficiency in Tokachi region of Hokkaido in Japan. The study was based on an assumption that the biofuel is produced and consumed within the region of Tokachi. With this assumption, an economic effect and environmental impact were evaluated by an input-output analysis. Accordingly, two scenarios were compared. The first was producing biodiesel fuel (BDF) from rape seeds grown for this purpose, while the second was producing bioethanol fuel (BEF) from nonstandard wheat which were separated from the standard wheat at the post processing. Although results showed that the production of both the BEF and BDF have an improved economic impact on Tokachi region, the overall summation showed that, the production of the BDF have further improved the economic activities in this region. Regarding the CO₂ emissions, it can be said that using the BEF or BDF leads to less emission than using the fossil fuels.

Production costs are an important issue in development of the plant factory. We developed a novel hydroponic cabinet to reduce the electricity cost, and examined its operability using the red leaf lettuce. This cabinet can adjust the light height to plant growth, and use the direct current power. We elucidated that the plant height became higher by adjusting the light height to leaf lettuce growth. At 30 days after transplant, the fresh and dry weight, leaf area and leaf number at light height adjusted treatment were significantly higher than the control. Our results indicate that changing the light height during plant growth was effective for reducing cultivation period and production costs.

A field survey was conducted to compare the working performance and cost of three types of power tillers for tillage operations in the Kampar Region of Riau Province in Indonesia. A total of 22 rotary tillers, 11 moldboard plows, and 27 hydro tillers were purposively selected from seven districts in the region. The managers, custom operators, and mechanics of these machines were interviewed in 2012 and 2013 to collect data. The results showed that hydro tillers were the best in terms of their working performance, operational cost savings, and profitability. These machines must be employed for only 3.07 ha/season for operators to break even. For these reasons, it is suggested that farmers would benefit most by choosing hydro tillers for tillage operations.

In order to increase efficiency and reduce the costs associated with chemical-free, environment-friendly disinfection methods for rice seed, we developed a device with the following purposes: to heat and pasteurize rice seed using steam condensation heat at high temperature during a short time, and to significantly simplify the cooling and drying process compared to the conventional hot water treatment. To select the optimal treatment conditions of the developed device, we focused on the measuring technique of grain temperature, which is used in grain drying engineering. The temperature of rice seed after heating was correlated with the seed germination rate under various heating conditions. We determined a temperature of 75±1°C as the optimal condition. This enables a control effect that is equally or more effective against rice seed-borne diseases than the conventional hot water treatment, without the negative effect of excess heat on seed germination.