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A Study on Transition of Rice Culture Practices During Chosun Dynasty Through Old References - VII. Transition of Weeding Technique (주요(主要) 고농서(高農書)를 통(通)한 조선시대(朝鮮時代)의 도작기술(稻作技術) 전개(展開) 과정(過程) 연구(硏究) - VII. 중경(中耕) 제초(除草) 방식(方式)의 전환(轉換))

  • 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.61-69
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    • 1992
  • Weed control in mid season of rice fields was systemized earlier in Korea than in Western Europe or China. The most representative method was pull out the weeds by hand followed by 'Seojibeob'(鋤地法 : method of hoeing) after draining. It was practiced 3 to 4 times to do extensively. Also, the purposes of transplanting arid direct seeding in rows were to manage weed problems effectively, which means that the development of cultural techniques is closely related to 'Seojibeob'(鋤地法). From the 17th century, techniques of deep plowing(because of principal : 'Simkyonginu'(深耨易耕 : Deep plowing make easy to hoe) and 'Hwanubeob'(火耨法 : derived from 'Hwakyong soonubeob) for effective weed management of waste lands were newly adopted and spreaded due to the situations ant that time. Thus, the practice of large-scale farming resulted from the adaptation of the techniques and methods described above. In the 18th to 19th century, the cultural methods, not much different from 'Seojibeob', were changed and the number of weeding was decreased. Especially, the techniques of dry seeding of rice were practiced by originating the ideal 'Seojibeob', in which water availability was improved in northern drought areas and also weed problems were easily managed. In addition, intensively large-scale farming showed weed management problems, so that 'Cheonilrok'(千一錄) by Woo Ha-young described the techniques of 'Banjongbeob'(反種法) or 'Hwanubeob' and in the end of the Chosun dynasty extensively large-scale farming was practiced by putting intensive and extensive techniques together. As the results, agricuitural productivity of Korea was increased 5 times by that time.

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Heavy Metals of Landfilled Biomass and Their Environmental Standard, Including CCA-treated Wood for Eco-housing Materials (방부처리 목재를 포함한 토양매립 바이오메스의 중금속 함량과 안전성 문제)

  • Lim, Kie-Pyo;Lee, Jong-Tak;Bum, Jung-Won
    • Journal of the Korean Wood Science and Technology
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    • v.34 no.4
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    • pp.37-45
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    • 2006
  • Recently, wood-framed houses has been built in the Korea for pension. Wood is good material for human healthy, while the construction lumbers are treated with preservative such as CCA (chromated copper arsenate), which contain some toxic elements for human body. However, if the waste woody biomass treated with various heavy metals, which has been collected from house construction or demolition, was fired in the field, and incinerated or landfilled after mass collection, such components will result in the toxic air pollutants in the burning or land fills, and spreaded into other areas. So the careful selection of wood and chemicals are required in advance for house construction, in particular, for environment-friendly housings. Therefore, this study was carried out to determine the content of toxic heavy metals in woody materials such as domestic hinoki and imported hemlock treated with CCA for housing materials, and the post-treated wood components such as organic fertilizer, sludge, dry-distilled charcoal and carbonized charcoal, to be returned finally into soil. The results are as follows. 1) The chemical analysis of toxic trace elements in various solid biomass required accurate control and management of laboratory environment, and reagents and water used, because of the error of data due to various foreign substances added in various processing and transporting steps. So a systematic analyzers was necessary to monitor the toxic pollutants of construction materials. 2) In particular, the biomass treated with industrial biological or thermal conditions such as sludge or charcoals was not fully dissolvable after third addition of $HNO_3$ and HF. 3) The natural woody materials such as organic fertilizer, sludge. and charcoals without any treatment of preservatives or heavy metal components were nontoxic in landfill because of the standard of organic fertilizers, even after thermal or biological treatments. 4) The CC A-treated wood for making the construction wood durable should not be landfilled, because of its higher contents of toxic metals than the criterion of organic fertilizer for agriculture or of natural environment. So the demolished waste should be treated separately from municipal wastes.

A Study on Environmental Standards of School Building (교사환경기준에 관한 연구)

  • Hong, Seok-Pyo;Park, Young-Soo
    • The Journal of Korean Society for School & Community Health Education
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    • v.1 no.1
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    • pp.11-43
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    • 2000
  • The purpose of this study was, through analyzing the previous researches, to grasp the present status of environment of school building(ESB), research the sundry records of each element and, through comparative analysis of the standard of ESB in Korea, the United States, and Japan, select the normative standard of ESB, to clarify the point at issue presented in Regulation of Construction & facility Management for Elementary and and Secondary School in Korea, and to suggest an alternative preliminary standard of ESB. To carry out a research for this purpose, these were required: 1. to investigate the existing present status of ESB, 2. to make a comparative analysis of the standard of ESB in each country, 3. to suggest the normative standard of preliminary standard of ESB, 4. to analyze the controversial points of the standard of ESB in Korea, 5. to suggest an alternative preliminary standard of ESB. The conclusions were as follows: 1. Putting, through analyzing the previous researches, the existing present status of ESB together, it seemed that lighting environment, indoor air environment and noise environment were all in poor conditions. 2. In the result of a comparative analysis of the standard of ESB in Korea, Japan and the United States, in Korea the factors of each lighting and indoor air environment were not presented properly, in Japan, in lighting environment aspect, the standard on natural lighting and the factors on brightness were not presented., and in the USA the essential factors of each environment were throughly presented. In the comparison of the standards on each factor, Korea showed that the standard level presented was less properly prescribed than those of the USA and Japan but it also showed that the standard levels prescribed in the USA and in Japan were mostly similar to the standard levels in records investigated. 3. With the result of the normative standard selection on School Builiding environment factor of prescribed in this study, the controversial points of the standard of ESB in Korea were analyzed and the result was utilized to suggest new preliminary standard of ESB. 4. As the result of the analysis of the controversial points of the standard of ESB in Korea, it was found that the standard of ESB in Korea should be established on a basis of School Health Act and be concretely presented in School Health Regulation and School Health Rule. The factors of each environment was improperly presented in the existing standard of ESB in Korea. Moreover the standard of them was inferior to that of the records investigated and those of in the USA and in Japan and it also showed that the standard of it in Korea was improper to maintain Comfortable Learning Environment. 5. A suggested preliminary standard of ESB acquired through above study as follows: 1) In this study a new kind of preliminary standard of ESB is divided into lighting environment, indoor air environment, noise environment, odor environment and for above classification, reasonable factor and standard should be established and the controling way on each standard and countermeasures against it should be considered. 2) In lighting environment, the factors of natural lighting are divided into daylight rate, brightness, glare. In the standard on each factor, daylight rate should secure 5% of a mean daylight rate and 2% of a minimum daylight rate, brightness ratio of maximum illumination to minimum illumination should be under 10:1, and in glare there should not be an occurrence factor from a reflector outside of the classroom. And the factors of unnatural lighting are illumination, brightness, and glare. In the standard on each factor, illumination should be 750 lux or more, brightness ratio should be under 3 to 1, and glare should not occur. And Optimal reflection rate(%) of Colors and Facilities of Classroom which influences lighting environment should be considered. 3) In indoor air environment factors, thermal factors are divided into (1) room temperature, (2) relative humidity, (3) room air movement, (4) radiation heat, and harmful gases (5) CO, (6) $CO_2$ that are proceeded from using the heating fuel such as oval briquettes, firewood, charcoal being used in most of the classroom, and finally (7) dust. In the standard on each factor, the next are necessary; room temperature: $16^{\circ}C{\sim}26^{\circ}C$(summer : $E.T18.9{\sim}23.8^{\circ}C$, winter: $E.T16.7{\sim}21.7^{\circ}C$), relative humidity: $30{\sim}80%$, room air movement: under 0.5m/sec, radiation heat: under $5^{\circ}C$ gap between dry-bulb temperature and wet-bulb temperature, below 1000 ppm of ca and below 10ppm of $CO_2$, dust: below 0.10 $mg/m^3$ of Volume of dust in indoor air, and ventilation standard($CO_2$) for purification of indoor air : once/6 min.(about 7 times/40 min.) in an airtight classroom. 4) In the standard on noise environment, noise level should be under 40 dB(A) and the noise measuring way and the countermeasures against it should be considered. 5) In the standard on odor environment, odor level under Physical Method should be under 2 degrees, and the inspecting way and the countermeasures against it should be considered.

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Changes of soil characteristics, rice growth and lodging traits by different fertilization and drainage system in paddy soil (논 토양에서 배수 및 시비조건에 따른 토양특성, 생육 및 도복 관련 형질의 변화)

  • Jeon, Weon-Tai;Park, Chang-Young;Park, Ki-Do;Cho, Young-Son;Lee, Jeom-Sig;Lee, Dong-Chang
    • Korean Journal of Soil Science and Fertilizer
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    • v.35 no.3
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    • pp.153-161
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    • 2002
  • The installation of subsurface drainage equipment is required for generalized use of paddy field and to improve soil productivity. The internal drainage of paddy field has improved root condition from the increasing of oxygen supply and removing noxious elements. This experiment was carried out to determine the effects of fertilization and drainage system on soil characteristic, growth and lodging trait of rice in paddy soil. A subsurface drainage system was installed a depth of 0.8m. Three fertilizer treatments were applied : 1) Conventional fertilized plot, 2) Controlled-release fertilized plot, 3) No-fertilized plot. In conventional plot, 110 kg N (as urea 46%), 45 kg P (as fused phosphate 20%) and 57 kg K (as potassium chloride 60%) per hectare fertilizers were applied. Controlled-release fertilizer was applied by 70% of N compared to the conventional plot. During the rice cropping, the water depth decrease was two times higher in subsurface drainage(SD) plot than non-drained(ND) plot. After harvesting of rice, the bulk density of sub-soil(10-20cm depth) was lower in SD plot than ND plot. After the experiment, the surface soil pH was high at SD plot but sub-soil was high at ND plot. Organic matter content was higher in all soil layer for SD plot than fro ND plot. Available $P_2O_5$ was not different between SD and ND plot for surface soil, but was high for SD plot for sub soil. The $NH_4{^+}-N$ content of soil, shoot dry matter, total nitrogen and $K_2O$ of rice plant were greater after panicle formation stage in SD plot. Total nitrogen content, $P_2O_5$ and $K_2O$ of rice root were high in SD plot after heading. Though the gravity center and 3rd internode length were greater, pulling force of rice root was higher in SD plot than ND plot. Rice yield in SD plot were low at conventional and controlled-release fertilized plot because of the greater field lodging, but yield in SD plot was high at no-fertilized plot. This study indicates that the fertilization level should be decrease on subsurface drainage system for rice cropping.

Influence of Lime and Phosphate Application on Amide and Ureide Nitrogen of Soybean Plants and Soil Microorganisms (석회(石灰)와 인산시용(燐酸施用)이 대두식물체중(大豆植物體中) Amide태(態) 및 Ureide태(態) 질소(窒素)와 토양미생물상(土壤微生物相)의 변화(變化)에 미치는 영향(影響))

  • Ko, Jae-Young;Ryu, In-Soo;Lee, Sang-Kyu;Suh, Jang-Sun
    • Korean Journal of Soil Science and Fertilizer
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    • v.24 no.1
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    • pp.69-76
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    • 1991
  • A pot experiment was conducted to find out the effects of lime and phosphate application on the changes of number of soil microorganisms, indigenous Rhizobium japonicum, nodule formation, and ureide-and amide-N in leaf and stem exudate of soybean plant under uncultivated hillside red earth in very low pH value, organic matter, available phosphate, and cation exchange capacity. The results obtained were summarized as follows : 1. The plant height, stem length, root dry weight and nodule weight were significantly increased with the application of lime and phosphate application than that of control plot. 2. The concentration of amide-N in soybean plant at the 45 days after sowing was obtained as high in order of control>lime> lime+phosphate while the concentration was obtained in order of Iime+phosphate>lime> control at flowering stage 3. However, concentration of ureide-N in the soybean leaf at the 45 days after sowing was obtained as high in order of control>lime>lime+hosphate while reversed concentration was obtained in stem. 4. The number of soil microorgan isms were increased with increase of pH value, available phosphate and soil exchangeable cation. 5. Significantly negative high correlation were obtained with the concentration of Al, Fe in soil and the concentration of amide-and ureide-N in soybean plant at flowering stage while positive correlation was obtained with plant growth and the concentration of ureide-N.

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Physicochemical Properties of Ripe and Dry Jujube ($Ziziphus$ $jujuba$ Miller) Fruits (성숙과 건조 대추의 이화학적 특성)

  • Hong, Ju-Yeon;Nam, Hak-Sik;Shin, Seung-Ryeul
    • Food Science and Preservation
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    • v.19 no.1
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    • pp.87-94
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    • 2012
  • This study was carried out to investigate the physicochemical characteristics of maturating and dried jujube. The moisture contents of the unripe and ripe jujube were found to be 84.66 and 66.45%, respectively, but that of the dried jujube was 31.48%. The crude-fat and crude-ash contents of the dried jujube were much higher than those of the maturing jujube. The carbohydrate contents of the unripe, ripe, and dried jujube were found to be 13.51, 27.94, and 61.70%, respectively, and the soluble-protein contents were 0.88, 1.73, and 3.71%. The reducing-sugar content of the dried jujube was 18.82%, higher than that of the ripe jujube. The sucrose contents of the unripe and ripe jujube were 10.15 and 16.66 g/100 g, respectively, and that of the dried jujube was 33.46 g/100 g. The major fatty acids that were found to compose jujube were palmitic, oleic, pamitoleic, linoleic, and linolenic acid. The myristoleic and arachidonic acid contents were higher in the dried jujube than in the ripe jujube, but the palmitoleic acid content was lower in the dried jujube than in the ripe jujube. The major minerals of jujube were found to be Ca, K, Mg, and P, and the total mineral contents of the unripe, ripe, and dried jujube in this study were 343.38, 584.94, and 331.56 mg/100 g, respectively. The polyphenol contents of the unripe, ripe, and dried jujube were 309.12, 248.80, and 23.34 mg/100 g, respectively, while the vitamin C contents were 610.04, 310.22, and 423.27 mg/100 g.

Effect of Feeding Frequency of Extruded Diets Containing Different Macro-nutrient Levels on Apparent Nutrient Digestibility in Grower Flounder Paralichthys olivaceus (영양소 함량이 다른 부상 배합사료의 공급횟수가 육성기 넙치의 영양소 소화율에 미치는 영향)

  • Seo, Joo-Young;Choi, Kyoung-Hyun;Choi, Jin;Lee, Sang-Min
    • Journal of Aquaculture
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    • v.18 no.3
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    • pp.160-166
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    • 2005
  • Two feeding trials were carried out to investigate apparent nutrient digestibility of flounder fed experimental diets containing different levels of macro-nutrients by satiation feeding rate (Exp-1) and feeding frequency (Exp-2). Triplicate groups of fish averaging 280 g were fed three experimental diets which contained different levels of carbohydrate, protein and lipid by two feeding regimes (satiation and 80% satiation) and four feeding frequencies (three meals a day, two meals a day, one meal a day and one meal every two days). Feces were collected using a fecal collection column attached to fish rearing tanks for 6 weeks. Apparent digestibilities of dry matter, protein, lipid, energy and carbohydrate were not affected by feeding satiation rate in Exp-1. Apparent protein digestibility was not affected by feeding frequency, whereas affected by dietary composition in Exp-2. Apparent protein digestibility of fish fed a high-protein diet showed a tendency to become higher compared to that of fish fed high-carbohydrate diet and high-lipid diet at the same feeding frequency. Apparent lipid digestibility was not affected by dietary composition, however, affected by feeding frequency. Apparent digestibilities of energy and carbohydrate were affected by both dietary composition and feeding frequency. Apparent digestibities of energy and carbohydrate in fish fed the high-protein diet showed a tendency to become higher compared to that of fish fed the high-carbohydrate diet and high-lipid diet at the same feeding frequency. Apparent digestibities of energy and carbohydrate tended to decrease with increasing of feeding frequency at the same dietary composition.

The Effect of Taipet-F and Bactokil on Retarding Lipid Oxidation in Boiled-dried Anchovy (Taipet-F와 Bactokil처리가 마른멸치의 산패방지에 미치는 효과)

  • Lee, Eung-Ho;Kim, Jin-Soo;Ahn, Chang-Bum;Park, Hee-Yeol;Jee, Seung-Kil;Joo, Dong-Sik;Lee, Seung-Won;Lim, Chi-Won;Kim, Il-Hwan
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.18 no.2
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    • pp.181-188
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    • 1989
  • The present study has been carried out to investigate the effect of Bactokil(made from didecyldimethyl ammonium chloride isopropanol and water) and Taipet-F (made from natural vitamin E, L-ascorbic acid, glyceride and gallic acid) on retarding lipid oxidation in boiled-dried anchovy. To process boiled-dried anchovy, boiled anchovy dried in cabinet drier $(dry-bulb\;temperature\;40^{\circ}C)$ for 1 hour were fronted with the Bactokil, the Taipet-F and mixture of Bactokil and Taipet-F, respectively. Anchovy fronted with chemicals were redried for 8 hours, packed in polyethylene film bag, and then stored at room temperature $(24{\pm}3^{\circ}C)$. These products were compared with control(untreated with chemicals) during storage. The changes in volatile basic nitrogen of each product was negligible during storage. The thiobarbituric acid and peroxide values of each product increased up to 10 days of storage, and then decreased. In color value of each product, L value increased, while n, b and ${\bigtriangleup}E$ values decreased during storage. The changes in brown pigment formation of each product increased up to final stage of storage. From the results of chemical analysis and sensory evaluation, the product treated with Taipet-F(0.5%, v/v) was the most effective on retarding lipid oxidation of the boiled -dried anchovy, followed by the product treated withthe mixture of Bactokil (0.04%, v/v) and Taipet-F (0.5%, v/v), the product treated with Bactokil(0.04%, v/v) and control, in the order named.

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Effect of Bluefin Tuna Bone on Calcium Metabolism of the Rat (참다랑어 골분이 흰쥐의 칼슘대사에 미치는 영향)

  • 김영만;윤군애;황혜진;지규용;손병일;배서영;김인령;정자영
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.1
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    • pp.101-106
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    • 2004
  • This study was conducted to examine the effect of bluefin tuna bone on the bone metabolism of the rats. Weaned 6-week old male rats were fed low-calcium diets for 2 weeks after the adjustment period. Rats were divided into 6 groups and were fed experimental diets for six weeks. Experimental groups were \circled1 Normal calcium: CC (0.5% CaCO$_3$; control) \circled2 TB (bluefin tuna bone powder) \circled3 CT (citrated bluefin tuna bone powder) \circled4 BB (bovine bone powder) \circled5 CL (calcium lactate) \circled6 Low calcium LC (0.15% CaCO$_3$). Low-calcium diet group (LC) showed the lowest calcium retention. There was no differences in calcium excretion in stool and calcium absorption among various calcium sources. Serum calcitonin levels were high in TB, CT and BB group compared to those in CC, CL LC group. Parathyroid hormone and osteocalcin levels showed no differences among experimental groups. Deoxypyridinoline (DPD) levels were significantly higher in LC group than in other groups. Wet weight of the femur were significantly high in TB and CT group, and dry weight of femur showed no differences among normal calcium groups. Bone density of femur in LC group was significantly lower than those of normal calcium feeding group, and TB group showed highest bone density among experimental groups. There was no differences in bone metabolism among various calcium sources. Therefore, it is pointed out that the amount of calcium intake is very important because there was significant differences between normal calcium diet and low calcium diet. According to the results of femur weight, ash, calcium and bone density, it is suggested that bluefin tuna bone have alternative effects to bovine bone powder on the maintenance of bone health.

A Study on the Production Structure and Biomass Productivity of Quercus variabilis Natural Forest (굴참나무천연림(天然林)의 생산구조(生産構造) 및 물질생산력(物質生産力)에 관(關)한 연구(硏究))

  • Kim, Si Kyung;Jeong, Jwa Yong
    • Journal of Korean Society of Forest Science
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    • v.70 no.1
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    • pp.91-102
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    • 1985
  • Growth and biomass production of natural stands of Quercus variabilis in relation to tree density were studied to obtain basic guide lines for future tending operation. Two natural stands of Quercus variabilis located at 900m (A stand: 6,600trees/ha, $15.84m^2/ha$, $\frac{19}{17-20}$) and 800m (B stand: 4,300trees/ha, $16.65m^2/ha$, $\frac{20}{17-21}$) elevation in Sancheong, Kyongnam Province were selected for the comparative study and following results were obtained through a sample plot method. After diameter of individual trees in the sample plots was measured, twelve average trees from each diameter class were cut felled to measure dry weight of $W_S$, $W_B$, $W_L$, $W_{Ba}$, and standing biomass and biomass production rates by a allometrior regressions related to $D^2H$. Vertical distribution of leaves along the stems indicated that photosynthesis was carried out 2.2m above the ground in Stand A and 1.2m in Stand B. Maximum photosynthesis was located 4.2m and 6.2m above the ground in Stand A and B, respectively. Leaf area index was 4.25ha/ha for Stand A, and 3.89ha/ha for Stand B. Above-ground standing biomass was 49.51 ton/ha for Stand A and 59.20 ton/ha and net annual production was 6.75 ton/ha/yr. for Stand A and 8.99 ton/ha/yr. for Stand B. The ratio of net annual production to standing biomass was 17.5% for Stand A and 16.7% for Stand B. Net assimilation rate was 2.75kg/kg/yr. for Stand A and 3.58kg/kg/yr. for Stand B. Stem wood production rate was 1.46kg/kg/yr. for Stand A and 2.09kg/kg/yr. for Stand B. Bark production rate was 0.60 kg/kg/yr. for Stand A and 0.34kg/kg/yr. for Stand B. Above data indicated that Stand B utilized growing spaces and sites more efficiently than Stand A. It is concluded chat productivity of natural stands of Quercus variabilis can be enhanced through optimization of basal areas and number of tree per hectare and that sound management of natural oak stands should be based on systematic sampling of the area for periodic productivity estimation.

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