Soil Classification of Paddy Soils by Soil Taxonomy (미국신분류법(美國新分類法)에 의(依)한 답토양의 분류(分類)에 관한 연구)
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- Korean Journal of Soil Science and Fertilizer
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- v.11 no.2
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- pp.97-104
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- 1979
According to Soil Taxonomy which has been developed over the past 20 years in the soil conservation service of the U. S. D. A, Soils in Korea are classified. This system is well suited for the classification of the most of soils. But paddy field soils have some difficulties in classification because Soil Taxonomy states no proposals have yet been developed for classifying artificially irrigated soils. This paper discusses some problems in the application of Taxonomy and suggestes the classification of paddy field soils in Korea. Following is the summary of the paper. 1. Anthro aquic, Aquic Udipsamments : The top soils of these soils are saturated with irrigated water at some time of year and have mottles of low chroma(2 or less) more than 50cm of the soil surface. (Ex. Sadu, Geumcheon series) 2. Anthroaquic Udipsamments : These sails are like Anthroaquic, Aquic Udipsamments except for the mottles of low chroma within 50cm of the soil surface. (Ex. Baegsu series) 3. Halic Psammaquents : These soils contain enough salts as distributed in the profile that they interfere with the growth of most crop plants and located on the coastal dunes. The water table fluctuates with the tides. (Ex. Nagcheon series) 4. Anthroaquic, Aquic Udifluvents : They have some mottles that have chroma of 2 or less in more than 50cm of the surface. The upper horizon is saturated with irrigated water at sometime. (Ex. Maryeong series) 5. Anthro aquic Udifluvents : These soils are saturated with irrigated water at some time of year and have mottles of low chroma(2 or less) within 50cm of the surface soils. (Ex. Haenggog series) 6. Fluventic Haplaquepts : These soils have a content of organic carbon that decreases irregularly with depth and do not have an argillic horizon in any part of the pedon. Since ground water occur on the surface or near the surface, they are dominantly gray soils in a thick mineral regolith. (Ex Baeggu, Hagseong series) 7. Fluventic Thapto-Histic Haplaquepts : These soils have a buried organic matter layer and the upper boundary is within 1m of the surface. Other properties are same as Fluventic Haplaquepts. (Ex. Gongdeog, Seotan series) 8. Fluventic Aeric Haplaquepts : These soils have a horizon that has chroma too high for Fluventic Haplaquepts. The higher chroma is thought to indicate either a shorter period of saturation of the whole soils with water or some what deeper ground water than in the Fluventic Haplaquepts. The correlation of color with soil drainage classes is imperfect. (Ex. Mangyeong, Jeonbug series) 9. Fluventic Thapto-Histic Aeric Haplaquepts : These soils are similar to Fluventic Thapto Histic Haplaquepts except for the deeper ground water. (Ex. Bongnam series) 10. Fluventic Aeric Sulfic Haplaquepts : These soils are similar to Fluventic Aeric Haplaquepts except for the yellow mottles and low pH (<4.0) in some part between 50 and 150cm of the surface. (Ex. Deunggu series) 11. Fluventic Sulfaquepts : These soils are extremely acid and toxic to most plant. Their horizons are mostly dark gray and have yellow mottles of iron sulfate with in 50cm of the soil surface. They occur mainly in coastal marshes near the mouth of rivers. (Ex. Bongrim, Haecheog series) 12. Fluventic Aeric Sulfaquepts : They have a horizon that has chroma too high for Fluventic Sulfaquepts. Other properties are same as Fluventic Sulfaquepts. (Ex. Gimhae series) 13. Anthroaquic Fluvaquentic Eutrochrepts : These soils have mottles of low chroma in more than 50cm of the surface due to irrigated water. The base saturation is 60 percent or more in some subhroizon that is between depth of 25 and 75cm below the surface. (Ex. Jangyu, Chilgog series) 14. Anthroaquic Dystric Fluventic Eutrochrepts : These soils are similar to Anthroaquic Fluvaquentic Eutrochrepts except for the low chroma within 50cm of the surface. (Ex. Weolgog, Gyeongsan series) 15. Anthroaquic Fluventic Dystrochrepts : These soils have mottles that have chroma of 2 or less within 50cm of the soil surface due to artificial irrigation. They have lower base saturation (<60 percert) in all subhorizons between depths of 25 and 75cm below the soil surface. (Ex. Gocheon, Bigog series) 16. Anthro aquic Eutrandepts : These soils are similar to Anthroaquic Dystric Fluventic Eutrochrepts except for lower bulk density in the horizon. (Ex. Daejeong series) 17. Anthroaquic Hapludalfs : These soils' have a surface that is saturated with irrigated water at some time and have chroma of 2 or less in the matrix and higher chroma of mottles within 50cm of the surface. (Ex. Hwadong, Yongsu series) 18. Anthro aquic, Aquic Hapludalfs : These soils are similar to Anthro aquic Hapludalfs except for the matrix that has chroma 2 or less and higher chroma of mottles in more than 50cm of the surface. (Ex. Geugrag, Deogpyeong se ries)
These studies were carried out for the elucidation of liming effect on the growth of rice seedlings and the chemical characteristics of an acid sulphate paddy that shows not only extremely high acidity of soil but also poor growth of rice plants, consequently low yield. Thus the liming effect on the changes of acidity, oxidation-reduction potential, and the contents of iron, aluminium, sulphate, and phosphorus fractions in the soil was investigated under the waterlogging and drying condition. The reclaimable or inhibitory effect of phosphorus, iron and aluminium on the growth of rice seedlings was also investigated under liming. The results are summarized as follows: 1. After liming, the pH of the acid sulphate subsoil decreased again on drying. 2. The oxidation-reduction potential reached a minimum after 5 days of flooding and greatly decreased on liming but increased after drying. 3. The contents of ferrous iron soluble in water-and Morgan's solution reached a maximum after 15 days of flooding and only the content of water soluble ferrous iron was greatly decreased. 4. The content of aluminium soluble in water-and Morgan's solution decreased by flooding and liming, and showed a tendency to increase on drying. 5. In the limed acid sulphate soil, the content of water soluble calcium showed a highly significant negative correlation with the content of sulphate and liming decreased sulphate content in the soil. 6. The contents of total phosphorus was 496.3 ppm in the acid sulphate topsoil and 387.5 ppm in the subsoil. The content of each phosphorus fraction was in the order of Fe-P>Occ. Fe-P>Ca-P>Occ. Al-P>Al-P and Fe-P content in the soil was the highest fraction among them. 7. Lime application increased greatly Ca-P and Al-P, and Occ. Fe-P and Occ. Al-P only slightly, but decreased Fe-P differently in each soil. 8. Effect of phosphorus on the dry matter yield of rice seedlings was great. The optimum amount of phosphorus to produce maximum dry matter yield of rice seedlings appeared to be 6.8% of maximum absorption (absorption coefficient) without liming and 10.0% with liming. 9. In rice seedlings liming increased the content and uptake of calcium and silica but decreased those of iron and aluminium. Phosphorus application increased the content and uptake of phosphorus and decreased iron while the application of iron and aluminium increased their contents and uptake but decreased those of phosphorus. 10. Liming greatly alleviated such toxicity of iron and aluminium. 11. When phosphorus was applied, the dry matter yield of rice seedlings showed highly significant positive correlations with uptake of phosphorus, calcium and silica each. When iron and aluminium were applied, dry matter yields indicated significant positive correlations with the contents or uptake of calcium and silica each, but significant negative correlations with the content or uptake of iron and aluminium. 12. Under the application of phosphorus and lime, dry matter yields showed significant positive correlations with pH and Morgan's extractable calcium each of the soil samples after harvest. Under the application of lime, iron and aluminium, dry matter yields showed significant positive correlations with pH, calcium and silica each, but negative correlations with iron and aluminium contents each of the soil samples after harvest.
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
1. Sixteen normal healthy subjects free from occult blood in the stool were selected and administered with their
For the purpose of establishing the systematized technical scheme of the cooperative rice cultivation which has most significant impact to improve rice productivity and the farm management, the author have studied the cultivation practices, and the variation of rice growth and yield between the cooperative rice cultivation and the individual rice cultivation at random selected 18 paddy fields. The author also have investigated through comparative method on the cultivation practices, management, organization and operation scheme of the two different rice cultivation methods at 460 paddy fields. The economic feasibility has been ana lysed and added in this report. The results obtained from this study are summarized as follows; 1. In the nursery, the average amount of fertilizer application, especially, phosphate and potassium, and the frequency of chemicals spray for the disease, insect and pest control at the cooperative rice cultivation are significantly higher than those of the individual rice cultivation. 2. The cultivation techniques of the cooperative rice farming after the transplanting can be characterized by a) the earlier transplanting of rice, b) the denser hills per unit area and the lesser number of seedlings per hill, c) the application of larger quantities of fertilizer including nitrogen, phosphate and potassium, d) more divided application of fertilizers, split doses of the nitrogen and potassium, e) the increased frequencies of the chemicals spray for the prevention of disease, insect and pest damages. 3. The rate of lodging in the cooperative rice cultivation was slightly higher than that of the individual rice cultivation, however, the losses of rice yield owing to the occurrence of rice stem borer and grass leaf roller in the cooperative rice cultivation were lower than that of the individual rice cultivation. 4. The culm length, panicle length, straw weight and grain-straw ratio are respectively higher at the cooperative rice cultivation, moreover, the higher variation of the above factors due to different localities of the paddy fields found at the individual rice cultivation. 5. The number of panicles, number of flowers per panicle and the weight of 1, 000 grains, those contributing components to the rice yield were significantly greater in the cooperative rice cultivation, however, not clear difference in the maturing rate was observed. The variation coefficient of the yield component in the cooperative cultivation showed lower than that or the individual rice cultivation. 6. The average yield of brown rice per 10 are in the cooperative rice cultivation obtained 459.0 kilograms while that of the individual rice cultivation brought 374.8 kilograms. The yield of brown rice in the cooperative rice cultivation increased 84.2 kilogram per 10 are over the individual rice cultivation. With lower variation coefficient of the brown rice yield in the cooperative rice cultivation, it can be said that uniformed higher yield could be obtained through the cooperative rice cultivation. 7. Highly significant positive correlations shown between the seeding date and the number of flowers per panicle, the chemical spray and the number of flowers per panicle, the transplanting date and the number of flowers per panicle, phosphate application and yield, potassium application and maturing rate, the split application of fertilizers and yield. Whilst the significant negative correlation was shown between the transplanting date and the maturing rate 8. The results of investigation from 480 paddy fields obtained through comparative method on the following items are identical in general with those obtained at 18 paddy fields: Application of fertilizers, chemical spray for the control of disease, insects and pests both in the nursery and the paddy field, transplanting date, transplanting density, split application of fertilizers and yield n the paddy fields. a) The number of rice varieties used in the cooperative rice cultivation were 13 varieties while the individual rice cultivation used 47 varieties. b) The cooperative rice cultivation has more successfully adopted improved cultivation techniques such as the practice of seed disinfection, adoption of recommended seeding amount, fall ploughing, application of red soil, introduction of power tillers, the rectangular-type transplanting, midsummer drainage and the periodical irrigation. 9. The following results were also obtained from the same investigation and they are: a) In the cooperative rice cultivation, the greater part of the important practices have been carried out through cooperative operation including seed disinfection, ploughing, application of red soil and compost, the control of disease, insects and pests, harvest, threshing and transportation of the products. b) The labor input to the nursery bed and water control in the cooperative rice cultivation was less than that of the individual rice cultivation while the higher rate of labor input was resulted in the red soil and compost application. 10. From the investigation on the organization and operation scheme of the cooperative rice cultivation, the following results were obtained: a) The size of cooperative rice cultivation farm was varied from. 3 ha to 7 ha and 5 ha farm. occupied 55.9 percent of the total farms. And a single cooperative farm was consisted of 10 to 20 plots of paddies. b) The educational back ground of the staff members involved in the cooperative rice cultivation was superior than that of the individual rice cultivation. c) All of the farmers who participated to the questionaires have responded that the cooperative rice cultivation could promise the increased rice yield mainly through the introduction of the improved method of fertilizer application and the effective control of diseases, insects and pests damages. And the majority of farmers were also in the opinion that preparation of the materials and labor input can be timely carried out and the labor requirement for the rice cultivation possibly be saved through the cooperative rice cultivation. d) The farmers who have expressed their wishes to continue and to make further development of the cooperative rice cultivation was 74.5 percent of total farmers participated to the questionaires. 11. From the analysis of economical feasibility on the two different methods of cultivation, the following results were obtained: a) The value of operation cost for the compost, chemical fertilizers, agricultural chemicals and labor input in the cooperative rice cultivation was respectively higher by 335 won, 199 won, 288 won and 303 won over the individual rice cultivation. However, the other production costs showed no distinct differences between the two cultivation methods. b) Although the total value of expenses for the fertilizers, agricultural chemicals, labor input and etc. in the cooperative rice cultivation were approximately doubled to the amount of the individual rice cultivation, the net income, substracted operation costs from the gross income, was obtained 24, 302 won in the cooperative rice cultivation and 20, 168 won was obtained from the individual rice cultivation. Thereby, it can be said that net income from the cooperative rice cultivation increased 4, 134 won over the individual rice cultivation. It was revealed in this study that the cooperative rice cultivation has not only contributed to increment of the farm income through higher yield but also showed as an effective means to introduce highly improved cultivation techniques to the farmers. It may also be concluded, therefore, the cooperative rice cultivation shall continuously renovate the rice production process of the farmers.
Go bears significant meanings in terms of cultural and entertaining functions in Asia Eastern such as China and Japan. Beyond the mere entertaining level, it produces philosophical and mythic discourse as well. As a part of effort to seek an identity of Korean traditional garden culture, this study traced back to find meanings of rock-go-board and taste for the arts which ancestors pursued in playing Go game, through analysis and interpretation of correlation among origin of place name, nearby scenery, carved letters and vicinal handed-down place name. At the same time, their position, shape and location types were interpreted through comprehensive research and analysis of stone-go-boards including rock-go-board. Particularly, it focused on the rock names related to Sundoism(仙道) Ideal world, fixed due to a connection between traces of Sundoism and places in a folk etymology. Series of this work is to highlight features of the immortal sceneries, one of traditional landscaping ideals, by understanding place identity and scenic features of where the rock-go-boards are carved. These works are expected to become foundation for promotion and preservation of the traditional landscaping remains. The contents of this study could be summarized as follows; First, round stone and square board for round sky and angled land, black and white color for harmony of yin and yang and 361paths for rotating sky are symbols projecting order of universe. Sayings of Gyuljungjirak(橘中之樂), Sangsansaho(商山四皓), Nangagosa(爛柯故事) formed based on the idea of eternity stand for union of sky and sun. It indicates Go game which matches life and nature spatiotemporally and elegant taste for arts pursuing beauty and leisure. Second, the stone-go-boards found through this research, are 18 in total. 3 of those(16.1%), Gangjin Weolnamsaji, Yangsan Sohanjeong and Banryongdae ones were classified into movable Seokguk and 15(83.9%) including Banghakdong were turned out to be non-movable rock-go-boards carved on natural rocks. Third, upon the result of materializing location types of rock-go-boards, 15 are mountain stream type(83.9%) and 3 are rock peak type(16.1%). Among those, the one at Sobaeksam Sinseonbong is located at the highest place(1,389m). Considering the fact that all of 15 rock-go-boards were found at mountainous areas lower than 500m, it is recognizable that where the Go-boards are the parts of the living space, not far from secular world. Fourth, there are 7 Sunjang(巡將) Go with 17 Hwajeoms(花點), which is a traditional Go board type, but their existences, numbers and shapes of Hwajeom appear variously. Based on the fact, it is recognizable that culture of making go-board had been handed down for an extended period of time. Among the studied rock-goboards, the biggest one was Muju Sasunam[