Journal of the Japanese Agricultural Systems Society
Online ISSN : 2189-0560
Print ISSN : 0913-7548
ISSN-L : 0913-7548
Volume 21 , Issue 1
Showing 1-6 articles out of 6 articles from the selected issue
Contributed paper
  • Yousuke CHOUMEI, Yositeru NAKAGAWA, Hideki KOJIMA, Hiroyuki HIROOKA
    2005 Volume 21 Issue 1 Pages 15-24
    Published: April 10, 2005
    Released: September 30, 2016
    JOURNALS FREE ACCESS
    In North area of Yagi Town, Kyoto prefecture, there is a livestock waste management system, named ‘the Yagi Bioecology Center', which utilize the wastes (feces and urine) from livestock for producing compost and liquid manure and generating electricity from methane gas. The objective of this study was to investigate the impression of residents in Yagi Town on the Center and identify the factors influencing the impression. Questionnaire surveys were conducted to junior high school students' parents and members in the self-government association in the North area of Yagi Town. Available questionnaires were obtained from 74 male and 173 female respondents. Five principle components (indexes) were extracted from three groups of questions using principle component analysis; the total evaluation index for the Center from the first question group, the evaluation index for organic agricultural products from the second question group, and the total consciousness index for environmental activities and indexes for disposal segregation and recycling activities from the third question group. The total evaluation index for the Center was taken as the dependent variable in this study. The effects of factors on the index were examined by least squares analysis of variance using three levels of models. The results showed that effects of occupation and the degree of attachment to Yagi Town and an interaction effect between the place of residence and the degree of attachment to Yagi Town were important sources of variance. The residents who deeply attach to Yagi Town tended to place the higher value on the Center and the tendency was strong for the residents who live in the North area where the Center is located. Furthermore, the residents who better know the function of the Center tended to highly evaluate the Center.
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  • Comparison of the spatial distribution of rice-planting date with environmental factors on the middle and upper areas of Ishikari Basin
    Toshihiro SAKAMOTO, Katsuo OKAMOTO, Hiroyuki KAWASHIMA
    2005 Volume 21 Issue 1 Pages 25-32
    Published: April 10, 2005
    Released: September 30, 2016
    JOURNALS FREE ACCESS
    There are few studies on the estimation the spatial distribution of rice-planting time. In this study, we tried to develop the methods to estimate the rice-planting time with multi-temporal RADARSAT data. And by using the distribution map of the rice-planting time, we investigated the relationship between the rice-planting time and the environmental factors (soil and temperature) spatially in the middle and upper areas of Ishikari Basin. The rice-planting time was quantified by analyzing the time series water status of paddy field. And it was also possible to estimate the total planted area for each district with estimation errors ranging from -11.5%~+25.7%. The root mean square error (RMSE) of the estimation was 1.5 km2. By making the distribution map of the rice-planting time and comparing it with the distribution map of the referential environmental factors, which are soil type and average temperature, it was not confirmed that there is no spatial relationship between the distribution of average temperature and that of rice-planting time. Additionally, it was noted that the paddy fields where the soil type is gley soil or peat soil tend to be planted later than that where the other soil are distributed.
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  • Chen LIU, Qinxue WANG, Toshiaki ICHINOSE, Kuninori OTSUBO
    2005 Volume 21 Issue 1 Pages 33-46
    Published: April 10, 2005
    Released: September 30, 2016
    JOURNALS FREE ACCESS
    In this research, the spatial distribution of migration and its major reasons in China during 1985-1990 at the county level was analyzed based on 1% original data of the Census 1990. As a result, the following facts were clarified. Firstly, the migrants were absorbed to the developed and developing cities such as the municipalities under direct control of the Central Government, capitals of province, and regions where the Reform and Open-door Policy was carried out at very early stages (Shenzhen, Guangzhou, Baoan, Dongguan and so on) from their surrounding areas. Secondly, the number of intra-province migrants, which occupied near 70% of the total migrants, was much more than that of inter-province migrants. The destinations of intra-province migrants were the capitals of province, mine lots, big cities, as well as regions where the Reform and Open-door Policy was carried out firstly. The destination of inter-province migrants were mainly located in the cities and surrounding areas of Beijing, Tianjin, Shanghai and Zhujiang River Delta. Thirdly, the number of Non-hukou migrants (movers who did not change their household residence registration) occupied near 50% of total migrants, though it is less than Hukou migrants (movers who did change their household residence registration). About 80% of Non-hukou migrants are from rural areas and about 50% of Hukou migrants are from urban areas. Almost 70% of the Hukou migrants are students who migrate into upper-grade administrative districts for the entrance of universities, or specialized schools, and professionals who migrate for job transfer. More than half of the Non-hokou migrants were workers, who moves for economical purpose and engage to the factories for spinning and weaving industry, processing industry and so on. Finally, economic development condition, especially the economic scale, was closely related with the in-migrants, which can be considered as the most important pulling factor. In addition, a simple regression model to calculate the number of in-migrants of all countries by GDP was suggested.
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  • Osamu WATANABE, Ichiro OTANI, Genji OHARA
    2005 Volume 21 Issue 1 Pages 47-57
    Published: April 10, 2005
    Released: September 30, 2016
    JOURNALS FREE ACCESS
    The utilization of biomass derived from plant materials is effective for the measures of global warming such as the reduction of aerial CO2, but there is few data about dispersed areas such as the paddy levees environment, which has the large amount of the above ground plant biomass resources. The Hyper-spatial image data of the 20 cm in the ground resolution by airplane survey in the region of Hidaka-Town, Hyogo Prefecture with a total area of 910 ha was used for the estimation of the above ground plant biomass in the paddy levees and the roadside slope vegetation that has never been fully explored. A field survey was conducted during late July to early August, there was frequently dominant of Imperata cylindrica in the paddy levees vegetation. Relationships between the paddy levees above ground plant biomass and NDVI (Normalized Difference Vegetation Index) values for the 40 sampling sites data showed a highly positive correlation (R2=0.6221, P<0.01), and the estimation of the mean above ground biomass shows 2.6 DWt/ha. If the above ground plant biomass was harvested at the third and forth times, the estimated biomass data shows 7.8-10.4 DWt/(ha yr), it indicate that the plant biomass of paddy levees coincides with the data of Grassland NPP(Net primary productivity) of 9.7 DWt/(ha yr) in the western region of Japan. It is possible that the utilization of the Hyper-spatial image data precisely estimates the small-scale and dispersed ground plant biomass resources.
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  • Kenji SUZUKI, Yukiyo YAMAMOTO, Masuo ANDO
    2005 Volume 21 Issue 1 Pages 59-64
    Published: April 10, 2005
    Released: September 30, 2016
    JOURNALS FREE ACCESS
    We proposed a method for evaluating the hydrology of small-scale on-farm ponds in northeast Thailand. First, we made interviews to farmers in the study site about their usage of on-farm ponds, and confirmed the ponds were used multi-purposely.Then, we simulated to estimate changes of water depths in typical ponds in catchment areas with different sizes. By the results,the relation between catchment area and minimum water depth for the past five years was shown. When the catchment area ratio (Rca: catchment area / on-farm pond area) was less than 5, the minimum water depth was 1 m or less, which makes fish culture difficult. When Rca was 9 or more, the minimum water depth was more than 1.75 m, and approximately 500 m3 of extra water per pond was available in dry season. These ratios were used as thresholds for categorization of ponds into three categories (category A: Rca ≧9; category B: Rca 5-9, and category C: Rca < 5) based on the catchment area which was determined from satellite imagery. We applied the method to 180 ponds in the study area. Half were belonged to category A, 10% to B, and 40% to C. The amount of water that was not being stored due to inappropriate pond location was more than 20% of the total pond capacity.
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  • Fuping ZHANG, Yongfen WEI, Tsuyoshi AKIYAMA, Yoshimichi SAIJOH, Hi ...
    2005 Volume 21 Issue 1 Pages 65-74
    Published: April 10, 2005
    Released: September 30, 2016
    JOURNALS FREE ACCESS
    In this research, the underground biomass of the Phyllostachys pubescens - Phyllostachys nigra mixed-stand was estimated in a 10 m×10 m study area settled at Fujihashi village by using the digital photograph. Investigation was carried out with a high-pressure washing machine to avoid destroying the underground parts including stump, rhizome and root. After the underground parts of the bamboo stand were entirely exposed, photograph was taken with a digital camera for each sub-divided small plot of 2 m×2 m. To each taken digital photograph, fine tuning was accomplished with Adobe Photoshop 6.0 so that the length of either the neighborhoods of right and left or the upper and lower sides may become the same, such items as fallen leaves, stones, and the stumps of trees were eliminated by visual decipherment. For the corrected picture, the areas of rhizome and root were computed through image processing with the digital number level, respectively. Then, the biomass of the rhizome and root was estimated according to the correlation between the area obtained from image analysis of the digital photograph and the actual dry weight, respectively (rhizome: r= 0.91, root: r=0.81). For living stumps, the biomass was estimated based on the allometric correlation between the diameter at the breast height (r= 0.98). While, for the dead stumps under the soil surface, the biomass was estimated using another allometric correlation established between the diameter at the top hairline of fine root and the dry weight of the shoot base died (r= 0.97). As a result, the biomass of the rhizome, root, and stump was estimated as 15.67, 9.51, and 10.01 t ha-1, respectively, with the total underground biomass (R) of the mixed bamboo stand being established as 35.17 t ha-1 for the area studied. The aboveground biomass (T) was obtained according to the allometric correlation between the diameter at the breast height and the surveyed aboveground dry weight, and the value of which was 23.31 t ha-1. As the results,T/R ratio of the study area was calculated as 0.66 by comparing the total underground biomass with the aboveground one. Furthermore, it was decided that the minimum survey area was 16 ~36 m2 for estimation of the underground biomass.
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