• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.160-165
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• 2010

To reduce the dose of fertilizers is very important to sustainable production of many horticultural crops, including strawberry. In order to practice the environment friendly agriculture of strawberry cultivation in plastic film house, soil chemical properties of 435 soil samples (232 for loam, 83 for sandy loam, and 120 for silt loam) in Chungnam Province from2008 to 2009 were determined. The average of pH, EC, OM, Av. $P_2O_5$, Ex. $K^+$, Ex. $Ca^{2+}$, Ex. $Mg^{2+}$, and Ex. $Na^+$ was 6.5, 2.28 dS $m^{-1}$, 26 g $kg^{-1}$, 910 mg $kg^{-1}$, 1.09 $cmol_c\;kg^{-1}$, 8.3 $cmol_c\;kg^{-1}$, 2.5 $cmol_c\;kg^{-1}$, and 0.58 $cmol_c\;kg^{-1}$, respectively. The content of Av. $P_2O_5$ in sandy loam soil was significantly higher than silt loam soil, whereas other properties showed no difference between soil texture. The kinds of strawberry cultivars showed no difference in soil chemical properties. The frequency distribution within optimum range of soil chemical properties was 30.6%, 35.4%, 37.0%, 5.3%, 8.5%, 8.5%, and 17.9% for pH, EC, OM, Av. $P_2O_5$, Ex. $K^+$, Ex. $Ca^{2+}$, and Ex. $Mg^{2+}$, respectively. Especially, excessive portion of Av. $P_2O_5$, and Ex. $Ca^{2+}$ were high 86.9%, and 86.0%, respectively. EC values of soil samples were significantly positive correlatoin with all chemical properties except soil pH. In principle component analysis of chemical properties in soil samples, the percentage of variance explained by PC 1 was 38.8%, while PC 2 explained 17.8%of the variance, for a cumulative total of 56.6%. These results were able to distinguish between soil textures and strawberry cultivars. Also, these results considered that understanding of soil chemical properties under using principal component analysis be able to improve amounts of fertilizers for sustainable agriculture in plastic film house.

• Korean Journal of Environmental Agriculture
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• v.32 no.2
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• pp.117-122
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• 2013

BACKGROUND: The scab, which is caused by Venturia nashicola, gives serious damages to pear trees. 'Niitaka' accounts for 82% of areas in pear cultivation. However 'Niitaka' is a scab susceptible cultivar. So, most of Korean farmers who growing pear trees have suffered by economic losses with the scab. In this research, we evaluated the scab resistance among elite pear seedlings to clarify genetics about the scab resistance. And we analyzed photosynthetic features with these seedlings to develop suitable cultivar which is advantageous for producing quality fruits during the growth and development of plants. METHODS AND RESULTS: We measured the rates of scab incidence among seedlings in a field experiment condition and an in-vitro test. An in-vitro test has been done with field experiment-based results. We made plant materials by grafting branches of each seedlings with 'Kongbae' rootstocks. And they had been grown for one month. Then, scab conidia suspension is sprayed to seedlings and sustained for 40 days under the controlled environment. As the results, 6 seedlings displayed lower incidence rates than other seedlings and 'Niitaka'. We also measured instant photosynthetic rates of each seedlings to determine the correlation between photosynthetic rates and fruit characteristics. However, it seemed that there is no correlation between them. CONCLUSION(S): Among the seedlings, 6 seedlings displayed the higher resistance to scab than other seedlings and 'Niitaka'. This characteristics is considered to be come from the gene expression of European pear. And we found that photosynthetic rate in trees rarely does not influence the fruit characteristics. It is considered to be affected by cultivar's own characteristics.

• The Korean Journal of Pesticide Science
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• v.20 no.4
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• pp.305-311
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• 2016

In cultivation environment, various pesticides are used and some of them could be volatilized into the air. This could affect farmer's health and also cause environmental pollution. This study was carried out to investigate the volatilization of pesticides, and use the reference data for preventing farmer's pesticide intoxication and securing worker safety. The experiment was conducted in a greenhouse using a lysimeter which was of $1m^2$ area and 1.5 m depth filled with upland soil. The pesticides treated in lysimeter soil were ethoprophos (5.0% GR), diazinon (34.0% EC), alachlor (43.7% EC), metolachlor (40.0% EC), chlorpyrifos (2.0% GR), pendimethalin (31.7% EC), carbaryl (50.0% WP), napropamide (50% WP), tebuconazole (25.0% WP) and imidacloprid (2.0% GR). Each pesticide was treated at a concentration of 770.5 mg based on A.I (%). The recovery of pesticide ranged from 77.4 to 99.3%. The volatilized pesticides in air were collected by personal air sampler with PUF tube at 4 l/min flow rate. In addition, temperature and humidity were measured. The collected samples were extracted using acetone in a soxhlet apparatus for 8 hours. The extracted pesticides were resoluted with acetonitrile and diluted 5 times. It was analyzed with LC-MS/MS. For 720 hours experiment, the largest vaporization amount of each pesticide in air was ethoprophos $15.24{\mu}g/m^3$, diazinon $5.14{\mu}g/m^3$, pendimethalin $2.70{\mu}g/m^3$, chlorpyrifos $1.76{\mu}g/m^3$, alachlor $1.40{\mu}g/m^3$, metolachlor $1.12{\mu}g/m^3$, carbaryl $0.27{\mu}g/m^3$, napropamide $0.22{\mu}g/m^3$, tebuconazole $0.11{\mu}g/m^3$ and imidacloprid $0.05{\mu}g/m^3$. The R value (coefficient of correlation) between volatilization and vapor pressure of pesticides is higher than 0.99. Therefore, there is high correlation between volatilization and vapor pressure of pesticides.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.3
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• pp.27-36
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• 2020

This study investigates the changes in inorganic composition and the microbial counts during the process of fermentation of mixed domestic organic resources for the development of alternatives for imported oil cake, and examines the characteristics of mixed fermentation organic fertilizer (MFOF). The effect of the MFOF on the lettuce growth is investigated in order to evaluate the possibility of replacing the existing mixed oil cake with the MFOF. Six kinds of domestic by-product resources, which are rice bran, distiller's dried grains, sesame meal, fish meal, and spent mushroom substrate, are mixed by mixing ratio and the composition was analyzed during the fermentation process for 90 days under moisture content 30% and sealed condition. During the 90 days of fermentation, the pH change of the MFOF was little, and the moisture content was maintained at 34-35% until the 60^th day of fermentation, and then decreased to 30-31% on the 90^th day. Total nitrogen content remained unchanged during the fermentation period, but total carbon content showed a significant difference on the 21^st day of fermentation. It was confirmed that the content of fertilizer composition (nitrogen, phosphate, and potash) of the MFOF was 8.7% or more, which is suitable for the minimum amount standard of the main nutrients to be contained in the organic fertilizer. During the fermentation process of organic fertilizer, the density of bacteria and actinomycetes increased until 60 days and 30 days, respectively, and thereafter little changes were shown, and fungal population showed an increasing trend. As a result of lettuce cultivation test in the greenhouse by applying the MFOF, the growth and yield were comparable to that of using the existing mixed oil cake fertilizer when 100% was applied based on crop standard nitrogen fertilizer level. The use of mixed fermentation organic fertilizer made with domestic by-product resources can be used for use in farms in the future and is expected to contribute to the stable production of environment friendly agricultural products.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.4
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• pp.21-27
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• 2014

Pig slurry has been considered as environmental waste to be treated in an appropriate manner. Moreover, water-born pollution loads by agricultural non-point source(NPS) pollution are expected to become intensified due to ongoing precipitation change. This study was conducted to develop a best management practice to reduce NPS pollution load by agricultural activity with pig manure compost. An eco-friendly way, small drainage pond, was suggested in this study to avoid direct drainage of agricultural runoffs and eventually reduce the amount of pollutants discharged into the surrounding aqua-environment. A small pond($12m^2$) was constructed at the corner of a rice paddy field($17,15m^2$) located in Suwon, Korea. Water was allowed to drain only via a small drainage pond. Sampling was repeatedly made at two locations, one from an entrance and the other from an exit of a pond, during the rice cultivation period(May to October, 2013). Generally, sampling was made only when runoff water drained through a pond, such as during and/or after rain(irrigation). The water quality analysis showed that all quality parameters(SS, $COD_{Mn}$, T-N, and T-P) were improved as water passed through the pond. The amount of runoff water was reduced by 67.8%. Suspended solids and $COD_{Mn}$ concentrations were reduced by 79.8% and 71.9%, respectively. In case of T-N and T-P amounts, the reduction rates were 73.6% and 74.9%, respectively. Our data implies that agricultural NPS pollution from rice paddy fields with pig manure-based fertilizer can be effectively managed when an appropriate drainage water management practice is imposed.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.1
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• pp.13-27
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• 2013

This study investigated flora and vascular plants area around Buyongdae where include optimum view point Okyeonjeongsa and Gyeomamjeongsa in Hahoe Village, Andong. Based on the findings, the aim of results was attempted to suggest the management plan of the vegetation area around Buyongdae which designated UNESCO World cultural heritage and folk village in Korea. The results of the study is as the following. All flora of this site, Buyongdae in Andong, were 301 taxa; 89 families, 217 genera, 251 species, 1 subspecies, 38 varieties and 11 forms. Vegetation of each of areas in site was classified Pinus densiflora as representative forest around Buyongdae, Quercus variabilis forest around Gyeomamjjeongsa and Koelreuteria paniculata forest in river cliff of Buyongdae. The 14 taxa(Polygala tenuifolia, Koelreuteria paniculata, and others) as the rare plants and the 7 taxa(Weigela subsessilis, and others) as endemic species were recorded in the surveyed site among the whole flora. The specific plants which is categorized to degree by the Ministry of Environment appeared as 32 taxa; degree IV was 4 species; Polygala tenuifolia, etc. and degree III was 10 species; Hypodematium glandulosopilosum, Pyrrosia petiolosa, etc. and degree I was 13 species; Hemiptelea davidii, Zizyphus jujuba var. jujuba, etc. Also, the 11 taxa were recorded in limestone area as the chamaephyte; Hypodematium glandulosopilosum, Celtis koraiensis, Siphonostegia chinensis, Artemisia gmelini, and others. The naturalized plants recorded as 25 taxa; Viola arvensis, Erechtites hieracifolia, etc. and invasion of Sicyos angulatus which is ecosystem disturbing plants. The naturalization rate(NR) was 8.3% and the urbanization index(UI) was 7.8% by field survey. For recovery of indigenous to traditional vegetation landscape in Buyongdae, Pinus rigida of upper-growth and Alnus sibirica of middle-growth need thinning. In addition, the site demands both sustainable management through long-term monitering and gradual elimination method for the naturalized plants including Sicyos angulatus where found in Kyumamjeongsa. Particularly, intentional planting for decoration and cultivation around Hwachunseowon, Helianthus tuberosus must be substitute with the native plants. Meanwhile, Polygala tenuifolia is potently demanded preventing habitate, confirming additional habitate, seed securing and preservation of gene resource internally or externally. Koelreuteria paniculata; denoting feature of river cliff, including Hypodematium glandulosopilosum, Siphonostegia chinensis, Zizyphus jujuba var. jujuba, Pyrrosia petiolosa, and Celtis koraiensis, also need an assertive preservation. Futhermore, Wisteria floribunda for. floribunda, located around Galmo rock to Chunggil course, remained by colonizing form, need preservation and observation for a while. Beside that, the information boards are required to educate visiting user about safe regulations on the narrow way in rock hill.

• Weed & Turfgrass Science
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• v.6 no.1
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• pp.11-20
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• 2017

Ninety species belonging to 28 families of weeds were identified in Korean rice fields. They were divided by eight provinces and 19 agro-climatic zones to be used as basic data of weed control. Looking at the regional weed occurrence, there were 52 species of 20 families in Gyeonggi, 37 species of 17 families in Gangwon, 41 species of 15 families in Chungbuk, 21 species of 12 families in Chungnam, 24 species of 13 families in Jeonbuk, 54 species of 21 families in Chonnam, 36 species of 20 families in Gyeongbuk, and 32 species of 16 families in Gyeongnam province, respectively. The most dominant family was Poaceae followed by Cyperaceae and Asteraceae. Mostly dominant species were Echinochloa spp., Monochoria vaginalis var. plantaginea, Scirpus juncoides var. hotarui, Eleocharis kuroguwai, and Sagittaria sagittifolia subsp. leucopetala with slight differences among the provinces. Although there were some differences in 18 climate zones from Taebaek sub-highlands to the southern part of the East Coast (except for the Taebaek Highland), the dominant species were Echinochloa spp., Monochoria vaginalis var. plantaginea and Scirpus juncoides var. hotarui. The most dominant family was Cyperaceae followed by Poaceae and Asteraceae. The differences of weed occurrence between provinces and agro-climatic zones were largely influenced by various weather conditions rather than the provinces. The changes in cultivation mode and herbicide use might influence as well.

• Journal of The Korean Association For Science Education
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• v.39 no.6
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• pp.717-728
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• 2019

The cultivation of creative convergence talent has become more important than ever, the Korean curriculum has also undergone many changes, aiming for convergence and integrated education. In addition to these changes in science and curriculum, we examined the changes in perception and Professionalism(PCK) of integrated science education of science teachers over the past decade. For this study, 359 elementary and secondary science teachers in 2008, when the 2007 revised curriculum was applied, and 360 elementary and secondary science teachers in 2018, when the 2015 revised curriculum was applied, were examined for 10 years of changes in perceptions and PCK of integrated science education. The conclusions from the analysis were as follows. First, in 2018, elementary and secondary science teachers were found to have a statistically significant increase in awareness of integrated science education. Nevertheless, cognition was found to be 'normal'. Second, teachers' perception of the necessity of improving the professionalism of teachers, providing teaching and learning materials, reducing the contents of learning, reducing the number of students and securing flexible timetables, and raising the perception of integrated science education for students and parents as a condition for the success of integrated science education, was analyzed to be significantly higher in 2018. Third, the results of PCK survey through self-diagnosis, teachers' PCK on integrated science education, such as competence to secure curriculum contents knowledge, comprehension of curriculum and class composition related to integrated science education, teaching strategy for integrated, creation of teaching and learning environment for integrated teaching, efforts to improve administrative constraints and the professionalism of integrated science education, was significantly higher than it was ten years ago. Therefore, the recent emphasis on convergence education has increased the experience of applying convergence classes in the field of education, and it was seen as a result of the continuous efforts of science teachers to meet the changes in the education paradigm.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.323-323
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• 2017

In many sub-Saharan African countries, boosting rice production is a pressing food security issue. To contribute to the increase in rice production, we have developed lines of NERICA 1 introgressed with the gene for spikelet number, Gn1a, and the gene for primary rachis-branch number, WFP by cross breeding. The performance of rice lines introgressed with the genes for yield related traits can be affected by cultivation environment and management. Thus, in this study, we aimed to evaluate the lines of NERICA 1 introgressed with Gn1a or/and WFP for yield and yield components under different nitrogen fertilization conditions in Kenya. A field trial was conducted at a paddy field in Kenya Agricultural and Livestock Research Organization-Mwea, Kirinyaga County ($0^{\circ}39^{\prime}S$, $0^{\circ}20^{\prime}E$) from August 2016 to January 2017. Eight lines of NERICA 1 introgressed with Gn1a and/or WFP, and their parents, NERICA 1 and ST12, were grown under 0 (NF) and $75(SF)kg\;N\;ha^{-1}$. At maturity, five hills per plot were harvested to determine the yield and yield components. The number of primary and secondary rachis-branches per panicle was measured on the longest panicle in each hill. Under SF, the introgression of WFP to NERICA 1 increased the number of primary and secondary rachis-branches by 27 and 25%, respectively. On the other hand, Gn1a did not increase the number of primary rachis-branches, whereas the number of secondary rachis-branches was increased by 38% on average. The number of primary and secondary rachis-branches of the lines introgressed with both genes increased by 25 and 56%, respectively. Although grain number per panicle increased 33% by Gn1a, 34% by WFP, and 43% by Gn1a+WFP, the yield increase by Gn1a, WFP, and Gn1a+WFP was only 14, 7, and 14%, respectively. The suppression of the yield increase was mainly attributed to the decline in the filled grain ratio. Under NF, WFP increased the number of primary and secondary rachis-branches by 20 and 19%, respectively. The introgression of both genes increased the former and the later by 19 and 35%, respectively. However, Gn1a did not change them under NF. Thus, even under NF, grain yield increased 11% by WFP and 24% by Gn1a+WFP due to the increased grain number although filled grain ratio declined. Our findings suggest that the introgression of Gn1a and WFP could contribute to the rice productivity improvement in sub-Saharan Africa even under low fertility conditions. Improving filled grain ratio of the lines introgressed with these genes by further breeding and fertilization management will be the focus of subsequent work.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.252-252
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• 2017

Nowadays water shortage is becoming one of the biggest problems in the Korea. Many different methods are developed for conservation of water. Soil water management has become the most indispensable factor for augmenting the crop productivity especially on soybean (Glycine max L.) because of their high susceptibility to both water stress and water logging at various growth stages. The farmers have been using irrigation techniques through manual control which farmers irrigate lands at regular intervals. Automatic irrigation systems are convenient, especially for those who need to travel. If automatic irrigation systems are installed and programmed properly, they can even save you money and help in water conservation. Automatic irrigation systems can be programmed to provide automatic irrigation to the plants which helps in saving money and water and to discharge more precise amounts of water in a targeted area, which promotes water conservation. The objective of this study was to determine the possible effect of automatic irrigation systems based on soil moisture on soybean growth. This experiment was conducted on an upland field with sandy loam soils in Department of Southern Area Crop, NICS, RDA. The study had three different irrigation methods; sprinkle irrigation (SI), surface drip irrigation (SDI) and fountain irrigation (FI). SI was installed at spacing of $7{\times}7m$ and $1.8m^3/hr$ as square for per irrigation plot, a lateral pipe of SDI was laid down to 1.2 m row spacing with $2.3L\;h^{-1}$ discharge rate, the distance between laterals was 20 cm spacing between drippers and FI was laid down in 3m interval as square for per irrigation plot. Soybean (Daewon) cultivar was sown in the June $20^{th}$, 2016, planted in 2 rows of apart in 1.2 m wide rows and distance between hills was 20 cm. All agronomic practices were done as the recommended cultivation. This automatic irrigation system had valves to turn irrigation on/off easily by automated controller, solenoids and moisture sensor which were set the reference level as available soil moisture levels of 30% at 10cm depth. The efficiency of applied irrigation was obtained by dividing the total water stored in the effective root zone to the applied irrigation water. Results showed that seasonal applied irrigation water amounts were $60.4ton\;10a^{-1}$ (SI), $47.3ton\;10a^{-1}$ (SDI) and $92.6 ton\;10a^{-1}$ (FI), respectively. The most significant advantage of SDI system was that water was supplied near the root zone of plants drip by drip. This system saved a large quantity of water by 27.5% and 95.6% compared to SI, FI system. The average soybean yield was significantly affected by different irrigation methods. The soybean yield by different irrigation methods were $309.7kg\;10a^{-1}$ from SDI $282.2kg\;10a^{-1}$ from SI, $289.4kg\;10a^{-1}$ from FI, and $206.3kg\;10a^{-1}$ from control, respectively. SDI resulted in increase of soybean yield by 50.1%, 7.0% 9.8% compared to non-irrigation (control), FI and SI, respectively. Therefore, the automatic irrigation system supplied water only when the soil moisture in the soil went below the reference. Due to the direct transfer of water to the roots water conservation took place and also helped to maintain the moisture to soil ratio at the root zone constant. Thus the system is efficient and compatible to changing environment. The automatic irrigation system provides with several benefits and can operate with less manpower. In conclusion, improving automatic irrigation system can contribute greatly to reducing production costs of crops and making the industry more competitive and sustainable.