• Title/Summary/Keyword: cultivation method and topographical region

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Distribution of Soil Fertility in Paddy Fields as Affected by Cultivation Methods and Topographical Regions (경작지대 및 재배방법에 따른 논토양의 비옥도 분포)

  • Kim, Dong-Jin;Kang, Da-Seul;Ahn, Byung-Koo;Lee, Jin-Ho
    • Korean Journal of Organic Agriculture
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    • v.23 no.3
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    • pp.595-604
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    • 2015
  • Soil chemical properties in paddy fields were found to be varied depending upon different cultivation methods such as environmentally-friendly, conventional, and two-crop farming systems and different topographical regions, namely plain, middle mountainous, and reclaimed land regions. Overall soil pH was found to be in optimal range (pH 5.5~6.5) for rice cultivation, except with conventional cultivation fields of the reclaimed lands in Jeonnam province. Electrical conductivity (EC) was relatively higher in the two-crop cultivation fields than in others. However, the concentrations of available phosphate as $P_2O_5$ were exceptionally higher in the two-crop farming fields, thus in submerged paddy condition the phosphate could be released into streams and rivers. Soil organic matter (SOM) contents were mostly in optimal range ($25{\sim}30g\;kg^{-1}$) for paddy field in Jeonbuk province, but in Jeonnam province they were slightly higher values of the range. The concentrations of available silicate ($SiO_2$) were mostly depended on the cultivation methods and the region, but some of paddy fields contained extremely high $SiO_2$ concentration. Statistical relationships among the soil chemical properties showed as follows: Correlations between EC values and exchangeable cation concentrations, between SOM contents and CEC values, and between available $SiO_2$ concentrations and pH, EC, exchangeable cations, and CEC values were positively significant, whereas total nitrogen concentrations were significantly negatively correlated with the concentrations of exchangeable K and Mg. These results might be very useful to establish benchmark paddy fields contained with certain levels of soil fertility.

Patterns of Subsistence Production in the Early Bronze Age in the Seoul/Gyeonggi Region (서울·경기지역 청동기시대 전기 생계자원(生計資源) 생산방식)

  • LEE Minyoung
    • Korean Journal of Heritage: History & Science
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    • v.56 no.3
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    • pp.22-44
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    • 2023
  • The subsistence economics of the early Bronze Age has focused on explaining the intensity of agricultural practices without sufficiently taking into account the diversity of production methods that may arise from cultural types or environmental factors. The problem appears to stem from paying insufficient attention to the question whether we should understand the transition from the Neolithic Age to the Bronze Age as continuous or discrete. This has hitherto blocked an avenue to investigate the gradual changes in subsistence resource production methods. Taking as its premise that changes in the production methods of subsistence resources in the Bronze Age have been continuous and gradual, this paper seeks to restore the production patterns of subsistence resources according to the variety of factors that may have influenced the early Bronze Age production method. With diverse cultural patterns and ecological spaces of the early Bronze Age being confirmed, the work of restoring the production methods of subsistence resources in a specific period is difficult to achieve with one or two stand-alone analyses. A more appropriate method would involve separating a number of different aspects related to the production of subsistence resources, analyzing and interpreting each, and in the final stage, synthesizing the analyses. The specific research method employed in this paper checked for compositional differences in stone production tools, functionally categorized according to a variety of factors that have a close relationship with the production of subsistence resources: cultural-environmental factors and cultural patterns, geographical and topographical factors, soil productivity, and size of settlement. The results of the analysis are as follows: for the early Bronze Age production pattern of subsistence resources in the Seoul and Gyeonggi regions, while no substantive differences were observed with respect to cultural type, geographical and topographical location, the results show statistically significant differences in the composition of production tools according to settlement size and soil productivity. Also, with an increasing ratio of settlement size and total production soil, increases in hunting and armoring tools, woodworking tools, and harvesting tools were observed; on the other hand, when it came to the ratio of fishing tools, the opposite relationship was observed. While a correlation between settlement size or crop cultivation productivity and dependence on hunting or farming was expected, the results of the regression analysis show that settlement size and soil productivity ratios do not have mutually significant relationships. The results thus illustrate that patterns of production differ according to a variety of factors, and no single factor is decisive in the adoption of subsistence resource production methods by a specific settlement. Therefore, the paper emphasizes the need to investigate the production patterns of subsistence resources according to the variety of cultural and environmental factors that make up settlements in early Bronze Age society.