• Title/Summary/Keyword: Newly reclaimed soil

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A Study on the Consolidation Effect of Adjacent Ground by Quick Lime Piles (생석회파일에 의한 주변지반의 압밀효과 분석에 관한 연구)

  • 천병식;고갑수
    • Journal of the Korean Geotechnical Society
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    • v.15 no.5
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    • pp.281-290
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    • 1999
  • The coastal area, particularly along the West and South coasts in Korea, is often reclaimed with dredged marine-clay to meet the demand of land capacity. A large number of ground improvement techniques are developed for such a newly formed soft clay deposit. However, the quick lime column method, which is effectively used for the purpose of ground improvement in the other countries, is seldom applied in Korea. This study, therefore, focuses on the development of appropriate soft soil improvement technique by using quick lime column. A model test as well as finite element analysis was conducted to identify the consolidation characteristics around the lime column. Although actual pore water pressure measured from model tests does not coincide with the predictions made by finite element method and Chen & Law's theoretical formula, their trends are quite similar. It is revealed from this study that the pressure caused by the expansion of lime column affects considerably the consolidation characteristics of the surrounding ground.

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Effects of the Application of Different Fertilizers on the Forage Yield and Quality on Newly Reclaimed Hilly Soil I. Changes in the forage yields, yield components and botanical composition (신개간 산지토양(山地土壤)에서 초지조성(草地造成) 비종(肥種)이 목초(牧草)의 수량(收量) 및 품질(品質)에 미치는 영향 I. 건물수량(乾物收量), 수량구성요소(收量構成要素) 및 식생구성비율(植生構成比率)의 변화)

  • Jung, Y.K.;Cho, J.S.
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.19 no.2
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    • pp.133-140
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    • 1999
  • This pot experiment was conducted to find out the forage productivity and quality in a grass/clover sward as affected by the application of three different fertilizers; double superphosphate(DS), fused Mg-phosphate(FP), and complex fertilizer(CF), on newly reclaimed hilly soil. This 1st part was concerned with the forage yields, yield components and botanical composition. The results obtained are summarized as follows: 1. The significant differences in the yields(relative yields, %) of whole forages and legume were laid in the following increasing order; CF(relative yield: 150.4% in whole forages and 169.7% in ladino clover) > FP(125.4% in whole forages and 121.7% in ladino clover) > DS(100.0%). The yield of orchardgrass was significantly reduced in the DS plot, compared with the yields in the FP and CF plots, whereas these showed no significant differences between the FP and CF plots. 2. In the botanicl composition, it showed that the rates of grass : legume were 48:52% in the DS and FP, and 40:60% in the CF. It was recognized that the application of complex fertilizer contributed to the increasing of the yields of whole forages, and especially legume yield and rate in the mixed sward.

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Effect of Inoculation with Bradyrhizobium sp. and Lime Types on Peanut Plant at Newly Reclaimed Area II. Nutritional Content in Seed (야산개간지(野山開墾地)에서 근류균(根瘤菌) 접종(接種) 및 석회(石灰) 비종별(肥種別) 시용(施用)이 땅콩 생육(生育)에 미치는 영향(影響) II. 종실(種實)의 양분함량(養分含量))

  • Lee, Deog-Bae;Choi, Song-Yeol;Kwon, Ta-Oh;Im, Geon-Jae;So, Jae-Don
    • Korean Journal of Soil Science and Fertilizer
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    • v.24 no.4
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    • pp.286-292
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    • 1991
  • This study was carried out to investigate in influence of inoculation B. sp. and lime types on nutrient content of peanut seed, and the correlation between nutritient contents in seed and plant. 1. Inoculated B. sp., content of crude protein, phenylalanine, isoleucine, cystine, histidine, aspartic acid, serine, and alanine in seed were increased significantly, but that of crude fat was decreased. 2. The content of crude fat was the highest without lime, glutamic acid was the highest with calcium sulfate, valine, phenylalanine, isoleucine, leucine, lysine, aspartic acid, serine, glycine and alanine with slaked lime, and histidine with calcium carbonate. 3. The content of crude protein in seed was negatively correlated with that of crude fat. The contents of chlorophyll, allantoin, ammonia, free amino acid, T-N, $P_2O_5$, and CaO in leaf at 100 days after sowing were positively correlated with the content of crude protein and various kinds of amino acid in seed, but negatively with the content of crude fat. The content of nitrate in leaf at 100 days after sowing showed the result of contrary tendency.

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Response of Potassium on Main Upland Crops (주요(主要) 전작물(田作物)에 대(對)한 가리성분(加里成分)의 비교(肥效))

  • Ryn, In Soo
    • Korean Journal of Soil Science and Fertilizer
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    • v.10 no.3
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    • pp.171-188
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    • 1977
  • The response and effect on main upland crops to potassium were discussed and summarized as follows. 1. Adequate average amounts of potash per 10a were 32kg for forage crop; 22.5kg for vegetable crops; 17.3kg for fruit trees; 13.3kg for potatoes; and 6.5kg for cereal crops. Demand of potassium fertilizer in the future will be increased by expanding the acreage of forage crops, vegetable crops and fruit trees. 2. On the average, optimum potash rates on barley, wheat, soybean, corn, white potato and sweet potato were 6.5, 6.9, 4.5, 8.1, 8.9, and 17.7kg per 10a respectively. Yield increaments per 1kg of potash per 10a were 4-5kgs on the average for cereal crops, 68kg for white potato, and 24kg for sweet potato. 3. According to the soil testing data, the exchangeable potassium in the coastal area was higher than that in the inland area and medium in the mountainous area. The exchangeable potassium per province in decreasing order is Jeju>Jeonnam>Kangweon>Kyongnam. Barley : 4. The response of barley to an adequate rate of potassium seemed to be affected more by differences in climatic conditions than to the nature of the soil. 5. The response and the adequate rate of potassium in the southern area, where the temperature is higher, were low because of more release of potassium from the soil. However, the adequate rate of phosphorus was increased due to the fixation of applied phosphorus into the soil in high temperature regions. The more nitrogen application would be required in the southern area due to its high precipitation. 6. The average response of barley to potassium was lower in the southern provinces than northern provinces. Kyongsangpukdo, a southern province, showed a relatively higher response because of the low exchangeable potassium content in the soil and the low-temperature environment in most of cultivation area. 7. Large annual variations in the response to and adequate rates of potassium on barley were noticed. In a cold year, the response of barley to potassium was 2 to 3 times higher than in a normal year. And in the year affected by moisture and drought damage, the responses to potassium was low but adequate rates was higher than cold year. 8. The content of exchangeable potassium in the soil parent materials, in increasing order was Crystalline Schist, Granite, Sedimentary and Basalt. The response of barley to potash occurred in the opposite order with the smallest response being in Crystalline Schist soil. There was a negative correlation between the response and exchangeable potassium contents but there was nearly no difference in the adequate rates of potassium. 9. Exchangeable potassium according to the mode of soil deposition was Alluvium>Residium>Old alluvium>Valley alluvium. The highest response to potash was obtained in Valley alluvium while the other s showed only small differences in responses. 10. Response and adequate rates of potassium seemed to be affected greatly by differences in soil texture. The response to potassium was higher in Sandy loam and Loam soils but the optimum rate of potassium was higher in Clay and Clay loam. Especially when excess amount of potassium was applied in Sandy loam and Loam soils the yield was decreased. 11. The application of potassium retarded the heading date by 1.7 days and increased the length of culm. the number of spikelet per plant, the 1,000 grain weight and the ratio of grain weight to straw. Soybean : 12. Average response of soybean to potassium was the lowest among other cereal crops but 28kg of grain yield was incrased by applying potash at 8kg/10a in newly reclaimed soils. 13. The response in the parent materials soil was in the order of Basalt (Jeju)>Sedimentay>Granite>Lime stone but this response has very wide variations year to year. Corn : 14. The response of corn to potassium decreased in soils where the exchangeable potassium content was high. However, the optimum rate of applied potassium was increased as the soil potassium content was increased because corn production is proportional to the content of soil potassium. 15. An interaction between the response to potassium and the level of phosphorus was noted. A higher response to potassium and higher rates of applied potassium was observed in soils contained optimum level of phosphorus. Potatoes : 16. White potato had a higher requirement for nitrogen than for potassium, which may imply that potato seems to have a higher capability of soil potassium uptake. 17. The yield of white potato was higher in Sandy loam than in Clay loam soil. Potato yields were also higher in soils where the exchangeable potassium content was high even in the same soil texture. However, the response to applied potassium was higher in Clay loam soils than in Sandy loam soils and in paddy soil than in upland soil. 18. The requirement for nitrogen and phosphorus by sweet potato was relatively low. The sweet potato yield is relatively high even under unfavorable soil conditions. A characteristics of sweet potatoes is to require higher level of potassium and to show significant responses to potassium. 19. The response of sweet potato to potassium varied according to soil texture. Higher yields were obtained in Sandy soil, which has a low exchangeable potassium content, by applying sufficient potassium. 20. When the optimum rate of potassium was applied, the yields of sweet potato in newly reclaimed soil were comparable to that in older upland soils.

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Comparison between phosphorus absorption coefficient and Langmuir adsorption maximum (전토양(田土壤) 인산(燐酸)의 흡수계수(吸收係數)와 Langmuir 최대흡착량(最大吸着量)과의 비교연구(比較硏究))

  • Ryu, In Soo
    • Korean Journal of Soil Science and Fertilizer
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    • v.8 no.1
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    • pp.1-17
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    • 1975
  • Laboratory experiments on the phosphorus adsorption by soil were conducted to evaluate the parameters for determination of phosphorus adsorption capacity of soil, which serve as a basis for establishing the amount of phosphorus required to improve newly reclaimed soil and volcanic ash soil. The calculated Langmuir adsorption maxima varied from 6.2-32.9, 74.7-90.4 and 720-915mg p/100g soil for cultivated soils, non-cultivated soils, and volcanic ash soils respectively. The phosphorus absorption coefficient ranged from 116-179, 161-259 and 1,098-1,205mg p/100g soil for cultivated soils, non-cultivated soils, and volcanic ash soils respectively. The ratio of the phosphorus absorption coefficient to Langmuir adsorption maximum was low in soils of high phosphorus adsorption capacity (1.3-1.5) and high in soils of low phosphorus adsorption capacity (2.2-18.7). Changes in the amount of phosphurus adsorption induced by liming and preaddition of phosphorus were hadly detected by the phosphorus absorption coefficient, which is measured using a test solution with a relatively high phosphorus concentration. The Langmuir adsorption maximum was a more sensitive index of the phosphorus adsorption capacity. The Langmuir adsorption maxima of the non-cultivated soils, which were treated with an amount of calcium hydroxide equivalent to the exchangeable Al and incubated ($25-30^{\circ}C$) for 40 days at field capacity, were lower than the original soils. The change in the adorption maximum on incubation following the liming of soils was insignificant for other soils. The secondary adsorption maximum of soils, which received phosphorus equivalent to the Langmuir adsorption maximum of the limed soils incubated ($25-30^{\circ}C$) for 50 days at held capacity, was 74.5, 5.6 and 23.8% of the primary adsorption maximum for volcanic ash soils, non-cultivated soils, and cultivated soils respectively. The amount of phosphorus adsorbed by soils increased quadratically with the concentration of phosphorus solution added to the soils. The amount of phosphorus adsorbed by 5-g soil samples from 100ml of 100- and 1,000mg p/l solution for the mineral soils and volcanic ash soils respectively was found to be close to the Langmuir adsorption maximum. The amount of the phosphorus adsorbed at these concentrations is defined as a saturation adsorption maximum and proposed as a new parameter for the phosphorus adsorption capacity of the soil. The evaluation of the phosphorus adsorption capacity by the saturation adsorption maximum is regarded as a more practical method in that it obviates the need for the various concentrations used for the determination of the Langmuir adsorption maximum.

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Effect of Inoculation with Bradyrhizobium sp. and Lime Types on Peanut Plant at Newly Reclaimed Area -1. Content of Nutrients in Plant and Yield (야산개간지(野山開墾地)에서 근류균(根瘤菌) 접종(接種) 및 석회(石灰) 비종별(肥種別) 시용(施用)이 땅콩 생육(生育)에 미치는 영향 -1. 식물체중(植物體中) 양분함량(養分含量) 및 수량(收量))

  • Lee, Deog-Bae;Im, Geon-Jae;Kwon, Tae-Oh;Lee, Sang-Bok;So, Jae-Don
    • Korean Journal of Soil Science and Fertilizer
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    • v.24 no.3
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    • pp.210-218
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    • 1991
  • This study was carried out to investigate the influence of inoculation with Bradyrhizobia and lime types on the nutrient content and yield of peanut. Inoculation size of Bradyrhizobium sp. HCR-46 was $8.2{\times}10^7$ cells per seed. Slaked lime, magnesium lime, and calcium carbonate were applied in an amount required for neutralization of soil. 150kg of calcium sulfate was fertilized to 10a of the experimental field. Sowing space was $40{\times}25cm$ under vinyl mulching. Leaves and stems for assay were sampled at 100 day after sowing. The obrained results are as follows. 1. Number and dry weight of nodule as well as dry weight of aerial part of peanut plant increased by inoculation with B. sp. and were the highest in calcium carbonate application. 2. Inoculated with B. sp., the contents of T-N, $K_2O$, MgO, allantoin, ammonia, free amino acid and chlorophyll increased, but that of nitrate decreased. 3. The contents of T-N, free amino acid, and chlorophyll were higher in the treatment of calcium carbonate, those of $K_2O$, MgO, allantoin, ammonia were higher in magnesium lime application, and those of CaO and nitrate were higher in slaked lime fertilization than any other lime types. 4. Contents of total sugar and starch in stem at 100 days were higher in the treatment of uninoculation than inoculation with B. sp., and those were highest in the calcium sulfate application than the other lime types. 5. Inoculated with B. sp. length of main stem and number of pods increased significantiy. Yield of seed was higher in inoculation with B. sp. than in uninoculation by 64%, and in the order of carbonate, magnesium lime, slaked lime, in calcium sulfate and non-application was the contribution of soil treatments to yield increases.

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The Impact of the Reclamation and Utilization of Idle Hillside Lands on Future Food Production in Korea (식량(食糧)의 안정적(安定的) 공급(供給)을 위한 산지개발이용의 필요성(必要性)과 전망(展望))

  • Park, Johng-Moon
    • Korean Journal of Soil Science and Fertilizer
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    • v.11 no.4
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    • pp.213-233
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    • 1979
  • It is generally agreed that the country's population will grow up to the level of 52 million by the year of 2000 and that due the active growth of industry, urbanization and road constructions, sizable portion of existing arable lands will be utilized for other purposes than agriculture in near future. From 1966 to 1977, it was estimated that, the average annual conversion of arable lands to other uses, was 12,909 ha. If this trend persists, it is predicted that from 1978 to 1991 when the 6th Five Years Economic Development Plan will terminate, approximately 181,000 ha of arable lands will be converted for other uses again. On the other hand, it is certain that the increased population (39 million in 1981, 45 million in 1991, 52 million in 2001) and the changes in food pattern along with the enhancement of living standards will bring about the phenomenal increase in demands for not only the staple food but also the livestock products such as meat, milk and eggs, vegetables and fruits. These future increased demands for various foods, naturally mean the increased needs for the expansion of arable lands at the same time. It is predicted that, if more activities than present scale are not taken for the expansion of arable lands, the national food self sufficiency level will drop from 79% in 1977 down to 62% in 1991. To meet the increased food demands in future, there are several ways and means. These will include the increased land use intensity, elevation of unit area yield levels, minimization of conversion of arable lands to other uses and expansion of arable lands through the reclamations of idle hillside lands and tidal lands. Among these, the expansion of arable lands through reclamations of idle hillside lands and tidal lands are more positive measures to cope with the increased production of foods in future. The reclamation of hillside lands demands more attention because it needs more advanced technologies in agronomical and engineering aspects, larger scale fundings and integrated socioeconomic considerations. In agromical aspects, the thechniques for early improvement of chemical and physical properties of soils, proper soil conservation measures and rational cropping systems are of particular importance. As to the financial supports to encourage the farmings in hillside land, much bold fund inputs are essential for the construction of roads, installation of irrigation and drainage facilities, soil conservation mechanisms, which will ensure the stabilized farming with reasonable incomes in the newly reclaimed lands.

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The Optimal Combination and Amount of Major Nutrients Computed by the Homes Systematic Variation Technique for the Hilly Pasture Development I. Determination of the optimal combinations of anions N:S:P and cations K:Ca:Mg in fertilation on a grass-clover mixed sward (산지초지개발을 위한 다량요소의 적정 시비비율 및 시비량 결정에 관한 연구 I. 혼파초지에서 음이온 N:S:P 및 양이온 K:Ca:Mg 적정시비비율)

  • 정연규;김성채
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.9 no.1
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    • pp.26-33
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    • 1989
  • This pot experiments were conducted to find out the optimal fertilization ratios of the N:S:P anions and K:Ca:Mg cations of major nutrients in an orchardgrass/ladino clover mixed sward. The optimum ratios in equivalent basis were computed by the Homes systematic variations technique. The soil samples were collected from the newly reclaimed soils, which are located on colluvial hilly area with a good consideration for the hilly pasture development. The results were summarized as follows; 1, the optimum fertilization ratios of major nutrients for the high yields by the forage species in a mixed sward were obtained (Table 4 in detail); N:S:P = 3:l: 1 and K:Ca:Mg = 1:l: 1 for grass and grass plus legume, and N:S:P = 1:6:43 and K:Ca:Mg = 1: 3: 1 for legume in general. 2. The yield increases from the systematic variations in this mixed sward were laid in following order; N > P >S-group and K >Mg >Ca-group for grass and grass plus legume, and P >S >N-group and Ca >Mg > K-group for legume. Especially, the yields were greatly increased at the N-group for grass, and at the Pand Ca-groups for legume. 3. Soil pH-value was descreased at the Sgroup, and somewhat increased at the Ca- and Mg-groups. The content of available $P_2O_5$, CEC and base saturation were greatest with the Ca-group. 4. At the N-group, the N-contents were highest and the P-contents were lowest in grass and grass plus legume, which resulted in the highest Ca/P ratio of 2.15 among the anion groups. Whereas the highest Ca/P ratio of 9.20 in legume was obtained at the Ca-group. Legume showed in general higher Ca/P ratio and lower K/(Ca+Mg) ratio than these in grass. 5 . There were differences in the effects of systematic variations of major nutrients on the dry matter yields and the mineral yields. The optimum fertilization ratios of anions and cations for the high mineral yields were obtained (Table E), which showed differences comparing with the ratios for the high dry matter yields. The antagonis between the cations K and Mg was known from the point of mineral yields of mixed forages.

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A Study on Transition of Rice Culture Practices During Chosun Dynasty Through Old References IX. Intergrated Discussion on Rice (주요(主要) 고농서(古農書)를 통(通)한 조선시대(朝鮮時代)의 도작기술(稻作技術) 전개(展開) 과정(過程) 연구(硏究) - IX. 도작기술(稻作技術)에 대(對)한 종합고찰(綜合考察))

  • Guh, J.O.;Lee, S.K.;Lee, E.W.;Lee, H.S.
    • Korean Journal of Weed Science
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    • v.12 no.1
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    • pp.70-79
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    • 1992
  • From the beginning of the chosun dynasty, an agriculture-first policy was imposed by being written farming books, for instance, Nongsajiksul, matched with real conditions of local agriculture, which provided the grounds of new, intensive farming technologies. This farming book was the collection of good fanning technologies that were experienced in rural farm areas at that time. According to Nongsajiksul, rice culture systems were divided into "Musarmi"(Water-Seeded rice), /"Kunsarmi"(dry-seeded rice), /transplanted rice and mountainous rice (upland rice) culture. The characteristics of these rice cultures with high technologies were based of scientific weeding methods, improved fertilization, and cultivation works using cattle power and manpower tools systematically. Reclamation of coastal swampy and barren land was possible in virtue of fire cultivation farming(火耕) and a weeding tool called "Yoonmok"(輪木). Also, there was an improved hoe to do weeding works as well as thinning and heaping-up of soil at seeding stages of rice. Direct-seeded rice culture in flat paddy fields were expanded by constructing the irrigation reservoirs and ponds, and the valley paddy fields was reclaimed by constructing "Boh(洑)". These were possible due to weed control by irrigation waters, keeping soil fertility by inorganic fertilization during irrigation, and increased productivity of rice fields by supplying good physiological conditions for rice. Also, labor-saving culture of rice was feasible by transplanting but in national-wide, rice should not basically be transplanted because of the restriction of water use. Thus, direct-seeded rice in dry soils was established, in which rice was direct-seeded and grown in dry soils by seedling stages and was grown in flooded fields when rained, as in the book "Nongsajiksul". During the middle of the dynasty(AD 1495-1725), the excellent labor-saving farmings include check-rowing transplanting because of weeding efficiency and availability in rice("Hanjongrok"), and, nurserybed techniques (early transplanting of rice) were emphasized on the basis of rice transplanting ["Nongajibsung"]. The techniques for deep plowing with cattle powers and for putting more fertilizers were to improve the productivity of labor and land, The matters advanced in "Sanlimkyungje" more than in "Nongajibsung" were, development of "drybed of rice nursery stock", like "upland rice nursery" today, transplanting, establishment of "winter barly on drained paddy field, and improvement of labor and land-productivity in rice". This resulted in the community of large-scale farming by changing the pattern of small-farming into the production system of rice management. Woo-hayoung(1741-1812) in his book "Chonilrok" tried to reform from large-scale farmings into intensive farmings, of which as eminent view was to divide the land use into transplanting (paddy) and groove-seeding methods(dry field). Especially as insisted by Seo-yugo ("Sanlimkyungjeji"), the advantages of transplanting were curtailment of weeding labors, good growth of rice because of soil fertility of both nurserybed and paddy field, and newly active growth because rice plants were pulled out and replanted. Of course, there were reestimation of transplanting, limitation of two croppings a year, restriction of "paddy-upland alternation", and a ban for large-scale farming. At that period, Lee-jiyum had written on rice farming technologies in dry upland with consider of the land, water physiology of rice, and convenience for weeding, and it was a creative cropping system to secure the farm income most safely. As a integrated considerations, the followings must be introduced to practice the improved farming methods ; namely, improvement of farming tools, putting more fertilizers, introduction of cultural technologies more rational and efficient, management of labor power, improvement of cropping system to enhance use of irrigation water and land, introduction of new crops and new varieties.

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