Local tendency in change of rice-wheat and barley double cropping in the north Kanto area: A case study of Gunma prefecture [Japan]

Gunma Prefecture is the northern limit region of double cropping of rice-wheat and barley. After 1925, in order to meet the severe agricultural requirement, intensive cultivation of rice with barley and sericulture using advanced agricultural technology was established. Under the recent tendency of reduction of agricultural production, the agriculture technology of this historical process has been inherited by present agriculture technology. The development of agriculture technology in Gunma Prefecture focuses on the extension of this technology. With this background, the main object of this study is to clarify the operational situation of double cropping of rice-wheat and barley double cropping in the northern limit region in the north Kanto area in Gunma Prefecture. An additional objective of the study is to clarify the continuing situation of double cropping as practiced in Gunma Prefecture. The analysis utilizes the .Kaplan-Meier method as survival data analysis, and the Cox Model. The major results of this analysis can be summarized as follows. 1)Rice-wheat and barley double cropping main area is the south area of Maebashi City in Gunma Prefecture at present. It is a flat area in the northwest of Kanto Plain. 2)According to the measuring result of Kaplan-Meier method, "Urban area" and "Flat farming area are" more advantageous than "Hilly farming area" and "Mountain farming area" for execution and continuation of double cropping. As a regulation factor of execution and continuation of double cropping, the site condition is an important factor. 3)According to the measuring result of Cox Model, "Classification of agriculture Area: Flat farming area", "The component ratio over 65-year-old of core persons mainly engaged in farming", "The penetration ratio of the combine", "The maintenance rate of paddy field. "These factors have the affect of low hazard On other side, "Classification of agriculture Area: Hilly farming area", "Classification of agriculture Area: Mountainous farming area", these factors affect to raise the hazard. The probability in which "Flat farming area", "Hilly farming area" and "Mountain farming area" carry double cropping in comparison with "Urban area with the unexercised, "Flat farming area": 0.5 times, "Hilly farming area": 1.6 times, and "Mountain farming area": 3.4 times.