This study aims to review previous studies and projects on hydropower generation using irrigation canals in Japan, and discusses their future perspectives. The Japanese agricultural sector uses around two thirds of the total water abstracted, which is channeled through dams, headworks, as well as 40,000 km of canal networks. Although such infrastructure would collectively have significant hydropower generation potential, it has attracted scant attention, due to the relatively low individual potential at each site. To effectively utilize such small and diffuse potentials, we would need to: (1) develop small waterwheels operable with small water heads and low flow rates; (2) develop techniques to identify suitable waterwheel sites within an existing canal system taking channel slopes and sidewall heights and seasonal variations in flow rates into consideration; (3) investigate the possibility of locally utilizing electricity on a micro-scale of a few kW, rather than selling it to the grid; and (4) modify the water management scheme where possible by, for instance, smoothing out flow rates across seasons and thus increasing the cost-effectiveness of power generation.

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A new method of drying early harvested wheat grains having high moisture content has been developed: classification drying based on moisture content using a thickness grader. Grain size is known to be roughly proportional to moisture content. We therefore clarified the relation between grain thickness and moisture content before the drying process, and demonstrated the possibility of new classification drying. Based on the results, we found that a 3.2-mm sieve was optimal for a roughly uniform separation of grains having moisture content of around 35%. For the drying process, the thicker grain group had higher moisture content and its flour was vulnerable to discoloration and degraded starch quality. Moreover, we found that it is important leave grains of high moisture content—the thicker grain group in classification drying—exposed to airflow in order to prevent degraded quality. Practical experiments conducted with a circulating batch dryer showed that the thinner grain group having lower moisture needs less time for drying due to the lower initial moisture content.

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A tilling robot capable of unmanned rotary tilling with the XNAV navigation system was examined to improve and expand the adaptability of the robot operation. Firstly, as an effective and safe method of using the robot, we proposed a method whereby one operator manually operated a conventional tractor while engaged in the unmanned operation of a robot tractor. As a result of the rotary tilling test, to which the use method was applied, the robot operation was performed without trouble, and one operator could perform the operation with efficiency about 1.8 times superior to manned operation. Secondly, as an application to farm work other than rotary tilling, operation software for seeding and soil paddling was created based on operation software for rotary tilling. From the results of robot wheat seeding field tests, it was proved that the operation could be successfully performed without trouble and that the conventional two-person work could be done by one operator. The robot soil paddling was also successfully performed with efficient operation paths compared to manned operation.

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Cultivating a greenhouse strawberry system for a harvesting robot should help profitability by boosting yields and labor-saving. We have developed a high-density cultivation system utilizing movable hanging beds that hold 1.5 times the number of plants of conventional table-top systems. With the proposed system, nine beds could be placed in a greenhouse 8 m wide, whereas only six beds would fit into a conventional system. The hanging beds move parallel to each other on a two-wheeled frame travelling on a greenhouse beam approximately 2 m above the floor. Although the usual greenhouse aisle width between strawberry beds is 0.5 m, this automatically expands to approximately 1 m when the robot enters the aisle. The operation is currently performed manually by pressing a switch. The strawberry yield achieved with the mobile system was 1.5 times that obtained with fixed hanging beds. Our next project involves developing a low-clearance moving platform on which a robot can move.

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A drip fertigation system was developed to improve vegetable production in sloping greenhouses. The system comprised a control unit, fertilizer injection unit, feed tank, feed pump, feed valves, and nutrient reservoir, which are also used in flatland drip fertigation systems. These components were placed in the upper part of a sloping greenhouse, and dripper lines with diaphragms were installed on longitudinal ridges. However, it resulted in unbalanced irrigation along the slope because when the irrigation was complete, the nutrient solution and water remaining in the dripper lines flowed out of drippers in the lower part of the dripper lines due to gravity. This problem was solved using a newly developed system, featuring a drainpipe and drain valve installed at the lower end of the dripper lines. On completing fertigation, the drain valve, which had been closed during the irrigation, was opened. The nutrient solution and remaining water in the dripper lines then immediately flowed into the drainage reservoir via gravity and not onto the field.

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In this study, the development of a laser-sensor-based, non-contact size control system for reeling thin raw silk is described. Thin raw silk cannot be reeled with current automatic reeling machines because they yield unusual silk fabrics. The effectiveness of the developed system was confirmed by a comparison of the properties of raw silk obtained from the developed system with that obtained from a conventional silk reeling machine. Next, for thin and thick raw silk, which are thinner than 10 d (denier, 1 denier = 1 gram per 9,000 meters) and thicker than 100 d, respectively, the influence of raw silk size and twist number on the characteristics of the obtained twisted yarn was examined. The results showed that the thread properties are strongly influenced by the twist number. Furthermore, the fiber number influenced the fiber structure, depending on the raw silk size. The bending characteristic of a 100 d silk was shown to be particularly good among the degummed silk. It was also shown that silk with lower bending strength and greater bending recovery can be crafted using thicker raw silk. In addition, thin and thick fabrics were woven using thin and thick raw silk respectively and the texture of each fabric was measured using the JIS test fabric silk as a control. The Hakugin fabric was found to be soft because the value of its “KOSHI” (stiffness) and “HARI” (anti-drape stiffness) was low and that of its “SHINAYAKASA” (flexibility) was high. Furthermore, the level of significance for the main and combinational effects for the “softness” and “luster” categories was 1%, that for the combinational effect for the “smoothness” category was 1%, and that for the main effect for the “likability” category was 1% respectively.

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Wollastoniella rotunda Yasunaga et Miyamoto is an effective predator of Thrips palmi Karny and a potential biological control agent for this pest of Japanese greenhouse vegetables. To determine alternative sources of prey for the mass rearing of W. rotunda used for T. palmi augmentative biocontrol, we examined the life history parameters of this predator as reared on two different prey species: Tyrophagus putrescentiae (Schrank) and Ephestia kuehniella Zeller eggs. When the predator nymphs were reared on T. putrescentiae and E. kuehniella at 25°C, their developmental times were 21.0 and 16.7 days, respectively, and their survival rates on T. putrescentiae and E. kuehniella at 25°C were 43% and 91%, respectively. The longevity of the predator females was 13.1 days on T. putrescentiae and 19.2 days on E. kuehniella, and their total fecundity was 15.0 eggs on T. putrescentiae and 56.5 eggs on E. kuehniella. The intrinsic rate of natural increase per day of W. rotunda on E. kuehniella (r_m = 0.087) was greater than that on T. putrescentiae (r_m = 0.031). We thus concluded that E. kuehniella is more suitable than T. putrescentiae as food for the mass rearing of W. rotunda.

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In 2007, we conducted field research in Sinazongwe District in Southern Province, Zambia, focusing on collecting indigenous information concerning the local climate, which was often embodied in proverbs involving weather forecasts. The indigenous information was compared with recently collected meteorological records and a relationship between popular folk knowledge, local climate, and global climate factors such as ENSO (El Niño and the Southern Oscillation) was suggested. Proverbs related to agriculture and climate were categorized into four types of indicators used to forecast rain: the emergence of butterflies; tree characteristics (producing shoots, flowering, and dropping water); wind direction, wind speed, and temperature; and wind sound. The first two types are based on seasonal changes in life forms, and the latter two use wind variations produced by synoptic pattern changes.

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The spatial distribution of vegetation trends identified by time series analysis of the normalized difference vegetation index (NDVI) for the Mongolian grasslands was cross-referenced with the recently obtained land use/cover data and socioeconomic information in the geographic domain. Global Inventory Modeling and Mapping Studies (GIMMS) dataset with an 8-km resolution provided by the Global Land Cover Facility (GLCF) of the United States were used to compute the vegetation trends. We cross-referenced the vegetation trends obtained from the land use/cover information as of 2005 extracted from the European Space Agency′s (ESA) GlobCover land cover dataset and the Mongolian livestock statistics. We found that vegetation or pasture degradation prevailed in the decade after 1990. Results indicated that 21.1% of the vegetation degradation occurred in croplands, mainly in the northcentral part of the country, which may be linked to the abandonment of large-scale state-operated farmland after 1990 when Mongolia made the transition to a market economy. A decline in the vigor of vegetation was also commonly observed in provinces where livestock numbers surged, and may be attributable to the over-exploitation of pasture resources. However, a greening belt was observed around the mountain areas along 45°N. The number of livestock remained relatively constant and no major land use/cover change was observed in these areas, suggesting that the improved vegetation vigor was attributable to the recent global climate change.

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Antioxidant activities and the lipid-decreasing ability of oat (Avena sativa L.) rice wine were investigated. Oat rice wine showed stronger metal chelating capacity, reducing power, and inhibition of lipid peroxidation than glutinous rice wine. The concentration of polyphenols (153.74 μg ml^-1) in oat rice wine also exceeded that in glutinous rice wine. Oat rice wine of the three dosages in this experiment increased superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activities, while decreasing the malondialdehyde (MDA) content, total blood cholesterol and triglyceride level, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in high-fatty mice. A medium dose (0.3 ml d^-1) of oat rice wine could reduce the contents of blood lipid and prevent liver damage. Oat rice wine also manifested stronger antioxidant activity than glutinous rice wine and was effective in decreasing the total cholesterol and triglyceride level in blood and ameliorating the fatty liver in vivo.

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Forest soils in the basalt region of Southeast Asia are important natural resources, due to their high agricultural potential and high capacity for carbon sequestration. To characterize the physicochemical properties and the components of the soil organic carbon of forest soils in the basalt region, five evergreen sites (E1-5) and one deciduous forest site (D1) were selected in Cambodia at elevations ranging from 132 to 908 m. The components of the soil organic carbon of each site were separated using a density fractionation approach, i.e. high- (≥ 1.6 g cm^-3) and low- (< 1.6 g cm^-3) density fractions. Soils of sites E1 and E2, at high elevation (> 600 m), were strongly weathered and characterized by a lower pH, a lower level of exchangeable bases, and a more reddish color than the other evergreen forest soils. The soils of sites E3 and E4, located on a hillside and at the base of a hill, respectively, had a high soil effective cation exchange capacity in the B horizons compared to those at sites E1-2 and E5. The soil of site E5 in the isolated basalt region had characteristics resembling those in sites E1-2 except for its high exchangeable aluminum content. The site D1 soil on a hillside was relatively young and shallow, and black in color. The carbon stock in the six forest sites (0-30 cm in depth) was 40.8-113.7 Mg C ha^-1 for high-density fractions and 3.3-7.6 Mg C ha^-1 for low-density fractions, respectively. The differences in vegetation types (deciduous vs. evergreen forests), mean annual temperature and free aluminum contents among forest sites were considered factors affecting the carbon content and carbon to nitrogen (C/N) ratio of high-density fractions. It was considered that the variously weathered parent materials, regulated by the relative position in the basalt plateau, were responsible for the gradient of soil morphology and soil nutrient conditions and characterized the soil carbon stock in the study area.

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