Journal of the Japanese Agricultural Systems Society
Online ISSN : 2189-0560
Print ISSN : 0913-7548
ISSN-L : 0913-7548
Volume 26 , Issue 1
Showing 1-6 articles out of 6 articles from the selected issue
Contributed Paper
  • Jong-Hwan KIM, Byungdug JUN, Kazuichi SUGIYAMA, Kenji TORAO, Yoshihiko ...
    2010 Volume 26 Issue 1 Pages 1-8
    Published: January 10, 2010
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    If changes in the physiological functions of farm products caused by environmental changes can be measured without any physical contact or destructive, then estimating of chemical component, forecast of yield, growth diagnosis, and management of crops become possible. In this study, four tea fields in Shizuoka were chosen as the study site. We have examined relations between the new leaves weight and NDVI for estimation of the yield and between some chemical components and NDVI for estimation of the quality period from 2004 to 2006. And we proposed a model formula for accuracy improvement. As a result, a positive correlation of the leaves weight, fiber content and NDVI was found. And there was a negative correlation between the total nitrogen, amino acid and NDVI. The study results proved the applicability of on-site remote sensing technology associated with the use of digital camera for the yield and quality estimation of new tea leaves.
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  • -A case study in Nakhon Ratchasima, Thailand -
    Miyuki YOSHIDA, Ryota NAGASAWA
    2010 Volume 26 Issue 1 Pages 9-15
    Published: January 10, 2010
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    The cassava is one of the main crops in norheastem Thailand. It is planted throughout the year and its cropping pattern varies from field to field. In this study, we analyzed cassava phenology and developed a method to determine the spatio-temporal distributions of cassava fields by applying ALOS satellite images. e selected three case study areas (10 x 10 km in size) from the vast cassava area in the Nakhon Ratchasima Province. DVI was calculated for each cassava field with temporal ALOS AVNIR-2 images taken on four dates (3,Sep.,2006; 4,Dec.,2006; 24,Apr.,2007; and 9,Jun.,2007) and the temporal changes of NDVI for each field were analyzed. Together with fieldwork results and characteristics of the seasonal changes of NDVI, the cropping system and phenology of the cassava were classified and mapped. The cassava fields were divided into four types in terms of cropping pattern. The area of pattern ① (planted in March to May and harvested starting in December) occupies more than 60 percent of all of the cassava fields. Additionally, there were regional characteristics in each spatial distribution of the cropping pattern.
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  • A case study of Furano city, Hokkaido, Japan
    Toshiki SATO, Nobuyuki TSUJI, Noriyuki TANAKA, Mitsuru OSAKI
    2010 Volume 26 Issue 1 Pages 17-25
    Published: January 10, 2010
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    In this paper, the food and energy self-sufficiency potential of Furano city, a region in central Hokkaido, Japan, was analyzed as a case study. First of all, Input-Output data was compiled for the main compartments of agriculture, dairy products, forestry, and citizenry in Furano city. Compartments were paddy rice, wheat, pasture, dent corn, onion, sweet corn, carrot, dairy cows, willow, forest, and citizenry. Secondly, supply and consumption per unit of land, per head of cattle, per capita related to food, energy, feed, nitrogen fertilizer were listed. Finally, by utilizing the specific figures, we analyzed the optimum land use model for energy self-sufficiency in Furano city using a linear programming analysis. As a result, we derived that the utilization of agricultural, livestock, and forestry biomass as energy results in an energy self-sufficiency potential of 20-48% influenced by nitrogen self-sufficiency
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Techinical Paper
  • Yasumaru HIRAI, Kenzo KAWAI, Masanori YOKOYAMA, Yuichiro BEPPU, Marika ...
    2010 Volume 26 Issue 1 Pages 27-35
    Published: January 10, 2010
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    Between 2006 and 2008, we surveyed the rice production in Hoshino village, Fukuoka prefecture, Japan, and examined the quality of irrigation water in this region. Through the survey, we obtained data for the 3 paddy fields where the same cultivar (Yumetsukushi) was cultivated in irrigation water with a wide range of inorganic nitrogen concentrations. In the field located downstream to tea fields, where large amounts of nitrogen fertilizers are used, and located upstream to a water system with small water volumes, the inorganic nitrogen concentrations in irrigation water were high (4.98 to 13.67mg/L) during the rice-growth season. This field showed notably higher SPAD values as compared to other fields where the amounts of basal nitrogen fertilization were equivalent or larger. In this field, the 1000-grain weight was large, and the protein content and weight of brown rice were the highest among the 3 paddy fields. Further, nitrogen supply from the irrigation water and the amount of nitrogen absorbed by rice were roughly calculated. The results of the calculation indicated that rice cultivation without nitrogen fertilization is possible in the field where inorganic nitrogen concentration in irrigation water is the highest.
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Review Article
  • An Overview
    Hiroaki KOBAYASHI
    2010 Volume 26 Issue 1 Pages 37-47
    Published: January 10, 2010
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    Biomass should act an important role in the development of renewable energy sources. The paper considers biofuels for transport from an economic standpoint of view. Their profitability, environmental performances and impacts on agricultural markets are discussed based on literatures, the author's case studies, theoretical illustration and empirical evidences. The author concluded: (1) biofuel production of first generation technology is difficult to be profitable taking into considerations of feedstock prices normally given in the agricultural markets, (2) literatures and some scientific evidences suggest that environmental benefits made by the first generation biofuels are still unclear particularly in the case that we count the impact through land use changes, (3) biofuel production, in the reality, is heavily supported by the government, and the relating policies could be categorized in agricultural supports such as export subsidies and deficiency payment-like schemes, (4) some econometric analyses providing possible impacts on food prices in the coming future are misleading because they seem to have failed, in most cases, to evaluate proper value of price elasticities in long-run supply functions.
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Data
  • Kenji ISHIDA, Miki TOKUOKA
    2010 Volume 26 Issue 1 Pages 49-55
    Published: January 10, 2010
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    Studying on the factors decreasing the settlement conditions in semi-mountainous areas turning attention to a sphere of life, we make clear measures to improve them. Both the number of elementary schools per residential area and the density of stores in country towns are very different from them in cities. To combine schools or other public facilities in countryside enlarges a sphere of life, and then the settlement conditions should be lowered. It is necessary that we improve them through the maintenance of community and public services, outside-supported risk management of agricultural promotion, urban and rural interchange and strengthening the industrial basis participating of various sectors in the region.
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