• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.1
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• pp.12-26
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• 2010

This study was conducted to investigate current states and management of the protected trees in Gangwon-do. There were 701 protected trees in 42 species designated by 2008, which were distributed at 425 places. Major species were Zelkova serrata(29%), Pinus densiflora(24%), Ulmus davidiana var. japonica(11%), and Ginkgo biloba(5%). The protected trees played various roles in the villages, mostly as sacred trees(43%). The 51% of protected trees were 300 years or more in age, the 53% were more than 20 m in height, and the 57% were more than 300 cm in girth at breast height. The 69% of the protected trees have been designated for protection in 1982 and the rest have been designated by the local cities by 2008. The species number of the protected trees in Youngseo region was greater than that of the Youngdong region. The major species were Zelkova serrata (33%) and Pinus densiflora(17%) in Youngseo region, and were Pinus densiflora (38%) and Zelkova serrata(19%) in Youngdong region. The ratio of native species to exotic species was 33:1 in Youngseo region, and were 25:6 in Youngdong region. The 29% of protected trees were located in the field, 28% in the mountain, and 25% in the villages. The 45% of the ground were covered by herbaceous plants, 39% exposed, and 10% gravel mulch. Most of the protected trees had good growing conditions. The 70% of the protected trees were under good maintenance, and the rest were under undesirable conditions. The soil characteristics of the protected tree areas in Gangwon-do were not much different from those of Korean average. It seemed to be necessary to increase designation of protected trees based on the tradition, history, local value and academic application in Gangwon-do. In addition, it is desirable to suggest plans to utilize and manage protected tree areas for enhancing the value of natural heritages in Gangwon-do.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.3
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• pp.312-317
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• 1985

Growth response and nutrients uptake of tobacco grown on mulched and non mulched plots were investigated during the growing period. 1. The whole growing time was about 25 days shorter and relative growth rate was faster in the mulched plot than in the non mulched plot. 2. Nitrate content of leaf in the latter stage of tobacco grown on the non mulched plot was more continuously increased compared with mulched plot. As a result in the latter stage of tobacco leaf nitrate form of nitrogen level was much higher on non mulched plot than on mulched plot. 3. Reducing sugar content in cured leaves of tobacco grown on the non mulched plot was lower that of the mulched plot. This difference in reducing sugar content was remarkable in the bottom leaves that nitrate content was highest. 4. Tobacco growing on nonmulched soil may cause to be low quality owing to increasing of nitrogen compound and decreasing of reducing sugar content in cured leaves. 5. As distributions of nitrate and potassium content in leaves at different stalk position was similar each other, nitrate and potassium ion considered to be counter ion in absorption and translocation through the tobacco plant.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.1
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• pp.70-77
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• 2016

The object of this study was to evaluate the effects of climatic elements on potato yield and create a model for estimating the potato yield. We used 35 yield data of Sumi variety produced in mulching cultivation from 17 regions over 11 years. According to the results, some climatic elements showed significant level of correlation coefficient with marketable yield of potato. Totally 22 items of climatic elements appeared to be significant. Especially precipitation for 20 days after planting (Prec_1 & 2), relative humidity during 11~20 days after planting (RH_2), precipitation for 20 days before harvest (Prec_9 & 10), sunshine hours during 50~41 days before harvest (SH_6) and 20 days before harvest (SH_9 & 10), and days of rain during 10 days before harvest (DR_10) were highly significant in quadratic regression analysis. 22 items of predicted yield ($Y_i=aX_i{^2}+bX_i+c$) were induced from the 22 items of climatic elements (step 1). The correlations between the predicted yields and marketable yield were stepwised using SPSS, statistical program, and we selected a model (step 2), in which 4 items of independent variables ($Y_i$) were used. Subsequently the $Y_i$ were replaced with the equation in step 1, $aX_i{^2}+bX_i+c$. Finally we derived the model to predict the marketable yield of potato as below. $$Y=-336{\times}DR_-10^2+854{\times}DR_-10-0.422{\times}Prec_-9^2+43.3{\times}Prec_-9\\-0.0414{\times}RH_-2^2+46.2{\times}RH_-2-0.0102{\times}Prec_-2^2-7.00{\times}Prec_-2-10039$$.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.319-325
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• 2018

The aim of the present study was to determine the influence of different fertilizer combinations on the growth, yield, and fruit quality of 'Duke' blueberry cultivar and the water quality of growth medium. The experiment was carried out with three year old 'Duke' blueberry bushes which were cultivated in containers ($60{\times}80{\times}40cm$) filled with 130 L peat moss and 40 L pearlite (v/v). Sawdust was used as the mulch in growth containers. Three different fertilizer combinations (FC) i.e., FC-1 consisted with standard solution, FC-2 consisted with nitrogen reduced by 10% from FC-1, and FC-3 consisted with nitrogen reduced by 20% from FC-1 were tested while, the ground water used as the control. The effects of different fertilizer combinations on shoot diameter, shoot length, number of shoots, leaf length, SPAD value (the relative content of chlorophyll), berry weight, soluble solids content, titratable acidity, and yield per bush in 'Duke' blueberry were examined. Also, the effects of different fertilizer combinations on pH, EC, $NH_4$ and $NO_3$ in 'Duke' blueberry growth medium were monitored. The highest pH and lowest EC, $NH_4$ and $NO_3$ in growth medium was recorded with control treatment during the experiment period. The maximum shoot diameter (3.7 mm) and shoot length (35.7 cm) was recorded for the FC-1. Highest number of shoots (47%) were recorded from 'Duke' blueberry bushes supplemented with FC-1 compared to other treatments. The fertilizer combinations supplemented with nitrogen showed significant influence on leaf length and SPAD value compared to control 'Duke' blueberry bushes. However, the fruit quality attributes, i.e., berry weight, soluble solids content, and titratable acidity were not significant different among fertilizer treatments. The significantly highest yields per bush were recorded for FC-1, FC-2, and FC-3, as 2.2, 2.9, and 2.7 kg, respectively compared to control (0.2 kg). Although, the FC-1 was supplemented with highest nitrogen content it resulted low yield per bush while having high number of shoots and vigorous growth.

• Korean Journal of Weed Science
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• v.31 no.1
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• pp.34-40
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• 2011

Cover crop can be used to suppress weeds by competition for light and nutrient. Objective of this study was to evaluate the effectiveness of legume cover crops on change of weed community in no-till corn cultivation. Two legume cover crops, hairy vetch and crimson clover were grown in the field, and succeeding corn was sown on 4 May, 2010. The distribution of weed was surveyed at 15 April, 1 June, and 20 August. At 15 April, the weed biomass in hairy vetch field was higher than in crimson clover field. The dominant weeds were Capsella bursa-pastoris L. and Stellaria aquatica L. in hairy vetch and crimson clover fields, respectively. At vegetative stage of corn, occurred weeds in hairy vetch and crimson clover fields were four and six species, respectively, while the weed was occurred with nine species in conventional. Also the dry weight of weed was decreased by 82 and 75% in hairy vetch and crimson clover fields compared to conventional. On the other hand, after harvest of corn, occurred weed in hairy vetch, crimson clover and conventional was five, four and five species, respectively. Dry weight percentage of occurred weed in conventional was 23.5%, and the value was higher than 13.8 and 14.7% in hairy vetch and crimson clover fields, respectively. Stellaria aquatica L. as winter annual weed only occurred in cover crop field during corn growing season. It is these possibilities that low soil temperature and light interception by soil cover of legume cover crop.

• Journal of agriculture & life science
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• v.45 no.2
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• pp.69-83
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• 2011

The aim of the research was to provide basic information for a suitable management and utilization of protected trees by law. To achieve this aim, this study investigated the current state, management status and utilization of protected trees by law in Gyeongsan city. The result of the current state of protected trees indicated that there were 55 protected trees designated since 1982. These trees consisted of 8 species which were located at 41 places. Major species was Sophora japonica (30.9%), followed by Zelkova serrata (23.6%). The protected trees have been used as sacred trees (45.5%) in the villages, followed by scenic trees (36.7%). 38.2% of the protected trees were 200 to 300 years old and 54.6% of the trees were 15 to 30 m in height. 34% of the protected trees were located in the villages, followed by beside road (19.5%). Single trees (78%) were mostly planted. The result of the management status indicated that 58.5% of the root area in protected trees were covered with bare ground, followed by gravel mulch (19.5%). The average of soil hardness was 9.64 mm. The safety fence of tree was installed at 9 places (22%) and a stone wall was built at 22 places (53.7%). 70.9% of the protected trees had a surgical operation to prevent cavities and to cure decay. Granite stone signs were installed at 33 places. The result of the utilization of protected trees indicated that 13 places were used as a rest area in the villages. It consisted of shelters, benches, athletic facilities and outdoor tables. The research suggested potential places for a mini park(pocket park) to recover a local community by using surrounding available land and improving current rest areas of protected trees. The research presented here is a first step towards a more comprehensive analysis of protected trees in Gyeongsan and further research is needed.