Journal of the Japanese Agricultural Systems Society
Online ISSN : 2189-0560
Print ISSN : 0913-7548
ISSN-L : 0913-7548
Volume 25 , Issue 3
Showing 1-4 articles out of 4 articles from the selected issue
Contributed Paper
  • Kenji SUDO
    2009 Volume 25 Issue 3 Pages 137-144
    Published: July 10, 2009
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    There are various types of pasture-based dairy farm management based on optimal combinations of various factors such as number of cows, grazing method and area of self-supplying feed cultivation. Consideration was given here to the role of grazing in sustainable dairy farming. Establishment of meadows around the barn is a prerequisite for pasture-based dairy farming. Since the nutritive value of grazed grass with short plant length is higher than that of storage fodder, introduction of grazing will lead to a reduction in the amount of imported concentrate. The basic principle of pasture-based dairy farming to let cows do what they can do so as to reduce labor time, machinery costs and energy costs required for harvesting conserved forage, feeding the forage to cows in the barn and processing excreta from the barn. Results of calculations based on actual measurements conducted in the Tokachi region of Hokkaido in the case of 13-15 kg of herbage (dry matter basis) being secured during grazing season and roughage being fed as much as possible for cows during the barn housing season showed that 1) a field area of about 70a is required for one cow, 2) this field area almost corresponds to the area for spreading manure that is required for one cow based on calculation that takes into account environmental preservation and thus circulation of material is maintained, and 3) the impact of sudden rises in prices of imported concentrate can be reduced, which is advantageous from the viewpoint of sustainable agriculture production. Even in cases in which there is not sufficient pasture area, introduction of grazing is possible by shortening the grazing time within a day. However, it is necessary to prevent outflow of excreta elements from a farm caused by overgrazing or by unequal utilization of a paddock. Emphasis should be placed on environmental preservation in grazing, and consideration should be given to the number of grazing cows per unit area and grazing time in one day. Further studies should be carried out for monitoring and quantifying the environmental impact of grazing.
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  • - Case study of all Farmland on Okayama prefecture, Japan -
    Shigeo OGAWA, Takahiro SHIONO, Hiroshi YOSHISAKO, Takeo SHIMA
    2009 Volume 25 Issue 3 Pages 145-155
    Published: July 10, 2009
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    Agriculture activity has not only to product crops but also to have multi functionality like the function of soil erosion prevention. This paper evaluates the function of soil erosion prevention in Okayama prefecture which has many hilly and mountainous areas. This function is related to soil erosion, we apply the USLE (Universal Soil Loss Equation) to evaluate. Evaluated area is wide about 80 km X 100 km, we estimate the function based on GIS datasets. At first, we estimate soil erosion in present farm land conditions. Present farmland condition is determined from GIS and satellite images. Coefficients of USLE are determined from AMeDAS datasets, soil maps, DEM, aero photos, related reports of soil erosion and ground survey. Next, we assume the future scenario that paddy fields in hilly and mountainous area would be abandoned and be changed to natural landforms. We estimate soil erosion in this future scenario. We defined the function of soil erosion prevention is the differences of present soil erosion and future scenario. As a result, soil erosion in paddy fields of mountainous area would be estimated to 1.4 t・ha-1・y-1 in present condition and it would be estimated to 37.7 t・ha-1・y-1 under the future scenario. The farmers contract paddy fields in flat and levees are covered with vegetation. It is obvious that agricultural activity conserved the farmlands. Our method has good advantage for evaluating the function of soil erosion prevention in wide area and applies to many cases of scenarios.
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  • Sei UNN, Takashige SUGIMOTO, Atsushi KUROKAWA, Hiroshi TAKAHASHI, Kota ...
    2009 Volume 25 Issue 3 Pages 157-165
    Published: July 10, 2009
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    Today, because of the increase in operational sizes and asset values for livestock production, computers must effectively be utilized not only for data management but also for strategic risk analysis. In this paper, by using field data collected from 79 farrow-finish swine operations for one year, 13 productivity indices in the reproduction, which include the total number of pigs born per litter (TB) and the number of pigs weaned per sow per year (PWSY), and 10 growth productivity indices, including the annual death rate and the predicted number of pigs marketed were analyzed. Their appropriate distributions were first determined individually, and the goodness of fit was tested by Anderson-Darling test. By utilizing those fitted distributions and the Monte Carlo simulations, the sensitivity analysis revealed that TB had the largest positive effect (29.2%), followed by the largest negative effects of non-productive sow days (-28.7%) and piglet death rate during lactation (-28.7%) on PWSY. Additionally, the number of stillborn pigs per litter (-9.6%) and the lactation length (-3.2%) were shown to have comparable effects. Risk analysis for the number of pigs marketed and the total sales under the actual cases showed the relationship between the sales and its reliability, and revealed the effectiveness in actual usage for the decision-making.
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  • Byungdug JUN, Mayu SHIMAMOTO, Jong-Hwan KIM, Kazuichi SUGIYAMA
    2009 Volume 25 Issue 3 Pages 167-174
    Published: July 10, 2009
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    In this study, authors proposed a new monitoring system of the agriculture product with digital camera and GPS-enabled mobile phone as one of the useful tools which were effective device for the crop growth. And the developed WebGIS system in this research provides support for an e-mail function with GPS information, with even digital camera image through internet. A spectral photometer (2703 models made by ARRAY Co. Ltd.) and a high-performance CCD camera (Nikon D-100 based system) used for verification experiment in this paper. In addition, the CMOS(Complementary Metal Oxide Semiconductor) image sensor of digital camera and GPS-enabled function of mobile phone (Model SO903i and N904i of NTT DoCoMo Co. Ltd) were used for inspection accuracy. The correlation coefficient between the spectral photometer and the CCD camera about the vegetation index (NDVI) of the plant obtain the result of R 2=0.92 from verification experiment. And the CMOS sensor of mobile phone and the spectral photometer have calculated the relationship as a correlation coefficient R 2=0.76. The result of GPS machine survey error was less than 5m (RMSE error) in the room and the outdoors.This paper lastly explains an overview and characteristics of WebGIS system working on the Google Map. The filed database on the WebGIS server showed the information that was good tool for a field worker and manager of crop growth.
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