• Title/Summary/Keyword: characteristics of texture

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Effects of Salt Treatment on Yield and Physiological Characteristics of Flag Leaf at Heading Stage in Winter Barley (보리 출수기 염처리가 수량 및 지잎의 생리적 특성에 미치는 영향)

  • 최원열;김영민;박종환
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.47 no.6
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    • pp.409-412
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    • 2002
  • This research was conducted to obtain the fundamental data on salt injury and different responses among cultivars in winter barley (Hordeum vulgare L.). Salts did not affect yield components including number of panicles, stem length, grain number per ear and grain yield while reduced stem dry weight and thousand seed weight significantly with increasing concentrations of salt from 60 to 180 mM. NaCl had less injury effect on barley straw dry weight and thousand seed weight than did $MgSO_4$. Chlorophyll content and relative turgidity in flag leaf were reduced when treated with both salts, while free proline in the salt-treated leaf was increased. Content of proline in salt-treated barley was about 10 folds compared to the control. Based on yield components and physiological traits of flag leaf, the tolerance to salt injury was the greatest in Baegdong, followed by Dongbori#1, Mogpo#55, and Gangbori. The results suggested that salt- stressed barley at reproductive stage had higher free proline content, and that special management in this stage must be considered because salt stress at heading stage affect flag leaf growth as well as yield components Harmfully.

Mineralogy and Geochemistry of Ultramafic Rocks from the Singok Area, Western Part of Chungnam (충남 서부 신곡 지역에 분포하는 초염기성암의 광물조성 및 지구화학)

  • 송석환;송윤섭
    • Economic and Environmental Geology
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    • v.34 no.4
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    • pp.395-415
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    • 2001
  • In the Singok area, western part of Chungcheongnam-Do, two ultramafic ma~ses, Singok mass and Kaewol mass, occur as isolated lenticular bodies in the Precambrian Kyeonggi gneiss complex. The masses extend for several hundred meter to NNE direction, parallel to the main fault line of this area. The rocks are dunite and harzburgite, but partially and absolutely serpentinized. They dominantly show porphyroclastic and recrystallized textures with equigranular-mosaic and protogranular textures. In spite of differences among the alteration and metamorphism, the ultramafic masses are characterized by varying amounts of high fosteritic olivine ($Fo_{0.88-0.93}$), magnesian pyroxene ($En_{0.93-0.97}$), and tremolitic to tschermakitic hornblende with minor spinel, serpentine, chlorite, calcite, magnetite, phlogopite and talc. It is compared with adjacent gneiss complex containing amphibole, biotite, plagioclase, alkali-feldspar and quartz. Geochemically, these rocks show high magnesium number (Mg>90.38), and transitional element (Ni=595-2480, Cr==IOlO-4400, Co=36-120 ppm), low alkali element ($Na_{2}O$<0.3, $K_{2}O$<0.11, $Al_{2}O_3$<2.95 wt%) and depleted incompatible element contents, which is compared with adjacent rocks (Mg < 83.69, $Na_{2}O$=1.02-3.42 wt%, $K_{2}O$=O.67-5.65 wt%, $Al_{2}O_3$=9.15-16.86 wt%, Ni < 435 ppm, Cr < 1440 ppm, Co<59 ppm, enriched incompatible element contents). Overall characteristics of ultramafic rocks from the Singok and Kaewol masses are similar to the those of adjacent ultramafic bodies in Chungnam with worldwide orogenic related Alpine type ultramalic rocks. Calculated geothermometries suggest that the ultramafic rocks have experienced metamorphism in the condition ranging from the greenschist facies to granulite facies.

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Changes in Quality of Fried Rice with Red Snow Crab Meat Depending on the Storage Period and Temperature (저장기간 및 저장온도에 따른 붉은대게풍미 볶음밥의 품질변화)

  • Jung, Ji Hee;Lim, Ji Hoon;Jeong, Min Jeong;Jeong, In Hack;Kim, Byoung Mok
    • Korean journal of food and cookery science
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    • v.31 no.4
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    • pp.387-394
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    • 2015
  • The red snow crab lives at a depth 200-2,000 m in the east coast. It has a smooth taste with a rich texture. However mostly red snow crab are only utilized materials. For seafood development, research is needed on using red snow crab in various products. In this study, quality changes in fried rice prepared with red snow crab meat, red snow crab emulsion sauce and red snow crab effluent were investigated. Physicochemical, microbiological and sensory characteristics were determined during storage at -20, 4 and $25^{\circ}C$ for 5 weeks to assess changes in the quality of the fried rice. The pH and acidity values did not show any significant differences at $-20^{\circ}C$. The VBN and TBA values of fried rice stored at 4 and $25^{\circ}C$ were significantly higher than those of fried rice stored at $-20^{\circ}C$ during the same storage period. The viable cell count of the fried rice stored at $-20^{\circ}C$ changed little during the storage period. During storage at $25^{\circ}C$, the overall quality was initially 8.0, but rapidly decreased to 1.0 after 5 weeks. In conclusion, the best storage temperature for both quality and safety was $-20^{\circ}C$. The storage condition for instant rice containing red snow crab affects the quality and we confirmed the applicability of using materials from red snow crab.

Changes in Quality of Muskmelon (Cucumis melo L.) during Storage at Different Temperatures (머스크멜론의 저장온도별 저장 중 품질변화)

  • Youn, Aye-Ree;Kwon, Ki-Hyun;Kim, Byeong-Sam;Kim, Sang-Hee;Noh, Bong-Soo;Cha, Hwan-Soo
    • Korean Journal of Food Science and Technology
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    • v.41 no.3
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    • pp.251-257
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    • 2009
  • The effects of temperature variations during storage on the quality characteristics of muskmelons (Cucumis melo L.) were investigated. In samples stored at $4^{\circ}C$ and $10^{\circ}C$, weight losses were almost 2.9- and 3.4-fold higher, respectively, compared to samples stored at $0^{\circ}C$. Soluble solids slightly increased except in the samples stored at $10^{\circ}C$, but acidity decreased over the entire storage period. Firmness decreased with storage time, but the samples stored at $0^{\circ}C$ had a lesser decrease in firmness than the samples stored at other temperatures. Water loss from the muskmelon stalk was most inhibited, and vitamin C content was maintained for the longest period, with storage at $4^{\circ}C$. Mineral contents (Ca, Na, Fe, Mg, K) were best maintained in muskmelon samples stored at $10^{\circ}C$ for 15 days, but levels had decreased by 30 days. Microbiological quality was not appreciably different at any storage temperature at 18 days; however, samples stored at $4^{\circ}C$ and $10^{\circ}C$ had deteriorated by 25 days. The results of sensory evaluations indicated that taste was best retained in samples stored at $10^{\circ}C$ for 15 days, although changes in taste were evident at all storage temperatures. When the samples were stored over 22 days at $10^{\circ}C$, retention of texture and overall acceptability were more inferior compared to samples stored at $0^{\circ}C$ and $4^{\circ}C$. These results suggest that storage at $4^{\circ}C$ can be used to reduce deterioration in muskmelons without significant loss of their quality attributes.

Quality change of mini sweet pumpkins (suppress cultivation, fall planting) during storage at different conditions (가을작형 억제재배 미니단호박의 저장조건별 품질 변화)

  • Oh, Bong-Yun;Jo, Gyeong-Suk;Lee, You-Seok;Kang, Jeong-Hwa;Jang, Mi-Hyang;Hwangbo, In-Sik
    • Food Science and Preservation
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    • v.22 no.6
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    • pp.779-787
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    • 2015
  • We stored sweet pumpkins at $8^{\circ}C$, $12^{\circ}C$, $12^{\circ}C$ plasma curing and room temperature (control) for 180 days. During this time, the quality characteristics were analyzed within the different groups. No spoiling occurred in either of the storage conditions for up to 120 days, and the marketability was good. After 120 days, spoiling sharply increased by over 70% in the control group, while in the $12^{\circ}C$ group it decreased to 20~60%. Conversely, spoiling was completely absent in the $8^{\circ}C$ and $12^{\circ}C$ plasma curing groups during the overall 180 days of storage. The lowest moisture content was found in the $8^{\circ}C$ group and the quality of the pumpkins was excellent during the entire storage period. The color of pulp was better in the $12^{\circ}C$ and $12^{\circ}C$ plasma curing groups, with best results were found in the latest. Both the $8^{\circ}C$ and $12^{\circ}C$ plasma curing groups maintained their dark green surface colors, while both the $12^{\circ}C$ and control groups turned from green to yellow. All groups showed a reduction in their initial hardness, with the $8^{\circ}C$ group staying the hardest. Soluble solid and mealiness was increased to the storage during 90 days while decreased, that were long to maintain the mealiness texture in the $8^{\circ}C$ storage pumpkin. The overall acceptability from sensory evaluation was higher in the $12^{\circ}C$ plasma curing group, when compared to those of the $8^{\circ}C$, $12^{\circ}C$ and control groups storage conditions.

Effect of Garlic Stalk Silage on Performance and Carcass Characteristics of Hanwoo Steers (마늘대 사일리지 급여가 한우거세우의 성장 및 도체특성에 미치는 영향)

  • Chu, G.M.;Lee, H.J.;Park, J.S.;Cho, H.W.;Ahn, B.H.
    • Journal of Animal Science and Technology
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    • v.45 no.6
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    • pp.1007-1018
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    • 2003
  • This study was conducted to investigate the effect of feeding of garlic stalk silage on performance and carcass characteristics of Hanwoo steers. Feeding trial was conducted with 27 heads of Hanwoo steers and these animals were divided into two groups of control(rice straw) and garlic stalk silage. Animals consuming rice straw were fed concentrates and rice straw for 22 months from the 5 months of age and animals consuming garlic stalk silage were fed concentrates, rice straw and garlic stalk silage for 22 months from the 5 months of age. Animals fed rice straw and garlic stalk silage were fed 1.34 and 1.47, 1.69 and 1.74, 1.65 and 1.66% concentrates to body weight for the growing period, fattening period and finishing period, respectively. Animals fed rice straw and garlic stalk silage as roughage sources were fed 1.37 and 1.38, 0.65 and 0.63, 0.43 and 0.43% roughages to body weight for the growing period, fattening period and finishing period, respectively. Also, animals fed garlic stalk silage were offered 0.22 and 0.33% garlic stalk silage to body weight for the fattening and finishing period, respectively. Animals fed rice straw and garlic stalk silage as a roughage sources did not differ in average daily gain during the whole feeding periods. Animals of control group consumed less concentrates and roughage than those fed garlic stalk silage during the whole feeding periods. However, feed efficiency was not significantly different between both treatments. Beef yield including backfat thickness, eye muscle area and carcass weight was slightly lower in the animals fed garlic stalk silage than in the animals fed rice straw even though there were no differences between both treatments. However, beef quality including beef color, fat color, texture, maturity and marbling score was slightly higher in the garlic stalk silage-fed animals than in the animals fed rice straw although there were not statistically different between both treatments. Animals consuming garlic stalk silage was significantly(p<0.05) lower in shear value than those fed rice straw. Amino acid composition including essential amino acid and non-essential amino acid was not different between animals fed rice straw and garlic stalk silage. Eye muscle area of animals fed garlic stalk silage contained slightly higher oleic acid, less linoleic acid and arachidonic acid and more linolenic acid than that of animals fed rice straw only as a roughage sources. So eye muscle area of animals fed garlic stalk silage contained more mono-unsaturated fatty acid than that of animals fed rice straw and $\omega$6/$\omega$3 ratio was narrower in the animals fed garlic stalk silage than in the animals fed rice straw. Economic income was higher by 20% in the animals fed garlic stalk silage than in the animals fed rice straw. Therefore, It may be concluded that feeding of garlic stalk silage as a roughage sources to steers during the fattening period seems to improve meat quality, fatty acid composition and economic income.

Soil properties in Panax ginseng nursury by parent rock (모암별 인삼묘포지의 토양특성에 관한 연구)

  • Min, Ell-Sik;Park, Gwan-Soo;Song, Suck-Hwan;Lee, Sam-Woong
    • Korean Journal of Agricultural Science
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    • v.30 no.1
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    • pp.31-40
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    • 2003
  • A research has been done for growing characteristics of Korean ginseng in Geumsan of Chungnam Province. It had been made to determine the transitional element concentrations of the rocks, divided by biotitic granite(GR) and phyllite(PH). The physical and chemical properties of their weathering soils and ginseng nursery soils were analyzed. The texture in the GR weathering and ginseng nursery soils were sandy clay, and the texture of the PH weathering and ginseng nursery soils were heavy or silty clay. The bulk densities of the GR and PH weathering soils were $1.21{\sim}1.32g/cm^3$ and $1.26{\sim}1.38g/cm^3$, respectively. Also, the bulk densities of the GR and PH ginseng nursery soils were $1.02{\sim}1.10g/cm^3$, respectively. The pH (4.80) of the GR weathering soil were lower than the pH of the PH(5.34) weathering soil. The pH in the 2 year and 4 year-ginseng nursery soil of the GR were 4.39 and 4.40. In addition, those of the PH were 5.24 and 5.34, respectively. The difference in pH of the two nursery soils could be from the pH difference between the two parent materials. The organic matter contents of the GR weathering soils(0.24%) were higher than those of the PH(1.02%) weathering soils. The organic matter of the 2 and 4 year-ginseng GR nursery soils were 0.87% and 1.52%, and of the PH nursery soils were 2.06% and 2.96%, respectively. The total nitrogen contents of the GR weathering soils were 259.43ppm and of the PH weathering soils were 657.22ppm. Those of 2 and 4 year-ginseng GR nursery soils were 588.04ppm and 657.22ppm and those of the PH nursery soils were 1037.72ppm and 1227.96ppm, respectively. The nitrate and ammonium contents of the GR weathering soils were the extremely small, and those of the PH weathering soils were 6.7ppm and 9.94ppm. Those of 2 year-ginseng GR nursery soils(223.09ppm and 26.96ppm) were higher than those of PH(19.46ppm and 8.23ppm) nursery soils. And those of 2 year-ginseng PH nursery soils(14.22ppm and 16.84ppm) were lower than those of PH(306.93ppm, 34.21ppm) nursery soils. The difference was due to fertilizer types and more deposits of nitrate after oxidation of ammonium. The phosphate contents of the GR and PH weathering soils were 14.41ppm and 38.60ppm. Those of GR 2 and 4 year-ginseng nursery soils were 46.89ppm and 102.44ppm and those of the PH nursery soils were 147.04ppm and 38.60ppm. The cation exchange capacities of the GR weathering soils were 12.34me/100g and those of the PH weathering soils were 15.40me/100g. Those of 2 and 4 year-ginseng GR nursery soils were 15.80me/100g and 7.70me/100g and those of PH nursery soils were 12.14me/100g and 12.83me/100g. All of exchangeable cation($K^+$, $Ca^{2+}$, $Mg^{2+}$, $Na^+$) contents in the nursery soils were higher than those in the weathering soils. The $SO_4{^2-}$ contents of the weathering soils in both of the GR(5.98ppm) and PH(9.94ppm) were higher than those of the GR and PH ginseng nursery soils. The $Cl^-$) contents of the GR and PH weathering soils were a very small and those of the nursery soils(2-yr GR: 39.06ppm, 4-yr GR: 273.43ppm, 2-yr PH: 66.41ppm, 4-yr PH: 406.24ppm) were high because of fertilizer inputs.

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Studies of the Properties of Commercial Woods Grown in the Southern Part of Korea (한국산(韓國産) 유용목재(有用木材)의 기초재질(基礎材質)에 관(關)한 연구(硏究))

  • Chung, Byung-Jae;Lee, Jyung-Seuk;Kim, Yoon-Soo
    • Journal of the Korean Wood Science and Technology
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    • v.6 no.2
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    • pp.3-19
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    • 1978
  • Five species, Abies koreana Wilson (A. koreana), Castanopsis cuspidata var. Sieboldii Nakai (C. Cuspidata). Machilus thunbergii Sieb. et Zucc. (M. thunbergii), Styrax japonica (S. japonica), and Quercus acuta Thunberg(Q. acuta) growing in the southern part of Korea were selected for the investigation of wood properties. In order to evaluate the wood properties of these five species, anatomical, physical, mechanical, chemical and pulping characteristics were investigated. And this study also covered wood technological problems related to the drying, gluing, debarking, flooring, and wood workability so that these species might serve to the best advantage. The results obtained were summarized as follows: 1. The trunk of A. koreana with many knots was straight. However, the trunks of S. japonica and C. cuspidata were crooked. 2. A. koreana showed the longest and the widest ill the fiber morphology; 2.97mm in length, 39.3${\mu}$ in width. In general, fiber width of all the species investigated were greater than those of other Korean hardwoods. 3. The specific gravity of Q. acuta was 0.74${\pm}$0.03, and that of A.koreana was 0.34${\pm}$0.02. The range of specific gravity of the other species was 0.47-0.52. 4. The adsorption of water was propotioned inversely with the specific gravity, but the adsorption of humidity was proportioned with the specific gravity. In spite of their medium density, S. japonica showed the greatest adsorption, and M. thunbergii the least. The water adsorption of cross section was twice greater than that of lateral direction, and there was a slight difference in between the radial and the tangential direction. 5. Shrinkage for tested five species was ranged from 5.36 to 10.24% in tangential direction, and 2.83~6.13% in radial direction. Q. acuta recorded the greatest shrinkage rate, and A. koreana the least. The greater was the specific gravity, the larger was the shrinkage rate. 6. The mechanical properties of Q. acuta were similar to those of Quercus mongolica which grow in Kangwon-Do. Strength properties of C. cuspidata, M. thunbergii, A. koreana were equivalent to those of other Korean commercial woods with similar specific gravity, except S. japonica which showed slightly higher strength than that of other species with similar density. 7. Higher glue joint strength for urea and phenol adhesieves was recorded in the species of M. thunbergii and C. cuspidata, however, high-density species(Q. acuta) and even low-density species(A. koreana) did not show good joint strength. 8. The attractive figure of M. thunbergii in texture seemed to he appreciated for decoration. And the grain and texture of other species were proper for furniture and building materials. 9. All of the species except Q. acuta were considered good for wood workability. 10. The denser the specific gravity was, the longer the drying time took. However, severe drying defects were formed in M. thunbergii whose density was medium. 11. All the species were considered suitable for the flooring wood expect A. koreana whose density was light. 12. Pentosan component in all the species was great, and the amount of extractives in Q. acuta was worth noticing. 13. Yield in kraft pulp was above the level of economic pulp yield, i.e. 45% in all species. 14. Debarking was easy in the species of A. koreana and M. thunbergii, and debarking after being boiled in water was the most efficient in all species.

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Superconducting Characteristics of Melt Spun $YBa_2Cu_3Ag_{15}$ and $YbBa_2Cu_3Ag_x$ (x=5, 16 and 53) Microcomposites (융체방사법으로 제작한 $YBa_2Cu_3Ag_{15}$$YbBa_2Cu_3Ag_x$ (x=5, 16 and 53)미세복합재의 초전도 특성)

  • Song, Myeong-Yeop
    • Korean Journal of Materials Research
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    • v.5 no.7
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    • pp.880-887
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    • 1995
  • Melt spun YB $a_2$C $u_3$A $g_{15}$ and YbB $a_2$C $u_3$A $g_{x}$(x=5, 16 and 53) precursor alloy ribbons were oxidized at 263~322$^{\circ}C$, and heat-treated at 872~89$0^{\circ}C$ under 1.0atm oxygen pressure. In addition, about ten ribbons were stacked and coupled by pressing, and then followed the same heat treatment. YB $a_2$C $u_3$ $O_{7-{\delta}}$(1-2-3) or YbB $a_2$C $u_3$ $O_{7-{\delta}}$(1-2-3) phase was formed in both the ribbons and the multilayered specimens. The formed 1-2-3 phases were not texturized in all the ribbons, but slightly texturized in the multilayered specimens. $J_{c}$ was not achieved in all the ribbons at 77K and zero magnetic field. Among the multilayered specimens, YB $a_2$C $u_3$A $g_{15}$ and YbB $a_2$C $u_3$A $g_{16}$ showed $J_{c}$ of 260 and 180A/$\textrm{cm}^2$, respectively. YB $a_2$C $u_3$A $g_{15}$ and YbB $a_2$C $u_3$A $g_{16}$ are considered to be the appropriate compositions in producing textured superconducting oxides with improved $J_{c}$ by pressing. Onset critical temperature ( $T_{on}$ ) of the multilayered YB $a_2$C $u_3$A $g_{15}$ was 92K while those of YbB $a_2$C $u_3$A $g_{x}$(x=5 , 16 and 53) were 88~90K. , 16 and 53) were 88~90K.

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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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