• Korean Journal of Soil Science and Fertilizer
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• v.10 no.4
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• pp.225-233
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• 1978

Uptake and distribution of labelled urea, $NH{_4}^+$, and $NO{_3}^-$ by Tongil and Jinheung rice grown with each nitrogen source until ear formation stage under water culture system were as follows. 1. When the previous nitrogen source was same as one tested the uptake rate ($mg^{15}N/g$ d.w. root 2hrs, at $28^{\circ}C$ light) was great in the order of $NH_4$ >urea> $NO_3$ and higher (especially $NH_4$) in Tongil than in Jinheung. Rate limiting step (slowest) seems to be exist at R (root)${\rightarrow}$LS(leaf sheath) for urea, LS${\rightarrow}$LB(leaf blade) for $NH_4$ and M(medium)${\rightarrow}$R for $NO_3$. The fast step of translocation appeare to be at M${\rightarrow}$R for urea R${\rightarrow}$LS for $NH_4$ and LS${\rightarrow}$LB for $NO_3$. 2. The uptake rate of $NH_4$ by the urea-fed plant increased almost linearly from $18^{\circ}C$ via $28^{\circ}C$ to $38^{\circ}C$ in Tongil ($Q_{10}$=1.21 and 1.32 respectively) while no change in Jinheung ($Q_{10}$=0.99 and 1.00 respectively). It decreased by 12% in Jinheung under dark but uo change in Tongil. 3. The uptake rate of nitrogen source by different source-fed plant was great in the order of $NH_4{\rightarrow}^{15}NO_3$ $NO_3{\rightarrow}^{15}NH_4$, $urea{\rightarrow}^{15}NO_3$ and higher (especially $NH_4{\rightarrow}^{15}NO_3$) in Tongil. In the case of $urea{\rightarrow}^{15}NH_4$ it was same in $NH_4{\rightarrow}^{15}NO_3$ for Tongil and slightly lower than that in $NO_3{\rightarrow}^{15}NH_4$ for Jinheung. It was lower (especially Tongil) in $NH_4{\rightarrow}^{15}NO_3$ than in $NH_4{\rightarrow}^{15}NH_4 $ 4. The uptake rate (in $NH_4{\rightarrow}^{15}NO_3$) was higher during 15 minutes than during 2 hours and always higher in Tongil. 5. $^{15}N$ excess % and content in each part, and uptake rate of root seems to have their own significance relatling with metabolism and translocation respectively. The change of nitrogen nutritional environment and source preference of varieties were discussed in relation to field condition and efficient use of nitrogen fertilizer.

• Korean Journal of Soil Science and Fertilizer
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• v.5 no.2
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• pp.65-74
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• 1972

A local rice variety, Jinheung and newly bred IR667-Suwon 214 were grown in $5m^2$ concret pot with two spacings and two nitrogen levels and their ripening structure and its function were comparatively investigated to elucidate the causes of unusually low ripened grain ratio of IR667 lines. The following differences between two varieties were found. 1. Though IR667 had much lower ripened grain ratio (64%) than Jinheung (85%) grain yield(790 kg/10a) of IR667 was higher than that (760 kg/10a) of Jinheung. 2. Number of ripined grain per net assimiration rate (NAR) at 10 days after heading was a little higher in IR667 (6,490) than in Jinheung (6,360) consiting to lower grain weight ($29.9{\times}10^{-3}g$) in IR667 than $31.2{\times}10^{-3}g$ of Jinheung. But number of total grain per NAR was much higher (10,530) in IR667 than 7,290 of Jinheung indicating that it was the probable cause of low ripened grain ratio of IR667. 3. Extinction coeificient (K) was 0.115 in IR667 and 0.200 in Jinheung, thus IR667 could construct greater ripening structure per unit area. 4. Number of grain per LAI was decreased with increasing LAI at heading and the decreasing rate was similar for both IR667 and Jinheung. 5. Critical leaf area index at which crop growth rata (CGR) is maximum was 6.5 for IR667 and 5.2 for Jinheung. Below 5.2 of LAI net assimilation rate was always higher an Jinheung throughout the growing season. 6. The estimated optimum leaf area index having maximum grain yield was 7.4 for IR667 and 6.2 for Jinheung at 10 days after heading. However, actual leaf area index was 6.2 for IR-667 and 4.7 for Jinheung and these were even below critical leaf area index. 7. The decrease of LAI during ripening period was great in IR667 but photosynthesis per $m^2$ was decreased more rapidly in Jinheung. 8. Net assimilation rate (NAR) decreased with the increase of LAI at any time of ripening period. The decreasing rate of NAR with the increase of LAI was greater in IR667 with ripening. The greater decreasing rate of NAR in IR667 seemed to be attributed to low photosynthetic activity and high respiratory loss due to the requirement of higher optimum temperature of ripening. 9. Grain yield-ripened grain ratio curve showed less contribution of dry matter yield after heading to grain yield in IR667 than in Jinheung due to unfavorable ripening environment(specialy air temperature) indicating that yield of IR667 could most effectively increased through the improvement of ripening environment.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.2
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• pp.105-111
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• 2015

"Seedgreen" (Secale cereal L.), a new rye cultivar was developed by National Institute of Crop Science (NICS), RDA in 2013. It was developed from an open pollination from within 10 rye varieties or lines including "Chochun" in 1995. The line "SR95POP-S1-140-9-1-3-7-5-3" was selected for its excellent agronomic appearance, and was placed in yield trials for three years from 2008 to 2010. The new cultivar was designated "Homil50" and was placed in regional yield trials at the five locations around Korea from 2011 to 2013, during which time the name "Seedgreen" was given. This cultivar is an erect plant type and of a long size, with a dark-green leaf color, a yellowish-white colored, medium-diameter culm, and a brown-colored, medium-size grain. The heading and maturation dates of Seedgreen were April 22 and June 16, which were 3 days and 2 days earlier than that of "Gogu", respectively. Seedgreen also showed better winter hardiness and a greater resistance to lodging and wet injury compared to those of the check cultivar. Over three years, the average dry matter yield of Seedgreen was 8.3 ton $ha^{-1}$ (fresh yield = 39.8 ton $ha^{-1}$), which was harvested in late April and was lower than that of the check cultivar Gogu. The seed productivity of Seedgreen was approximately 4 ton $ha^{-1}$, which was 16 % more than that of the check. Seedgreen was higher to than Gogu in term of protein content (10.5% and 9.7%, respectively), total digestible nutrients (TDN) (58.3% and 57%, respectively), and TDN yield $ha^{-1}$ (4.81 ton and 4.77 ton, respectively). This cultivar is recommended as a fall sowing crop in areas where the average daily minimum-mean temperatures are higher than $-12^{\circ}C$ in January, and as a winter crop for whole-crop forage before the planting of rice or green manure around Korea.

• Journal of Plant Biotechnology
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• v.42 no.2
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• pp.71-76
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• 2015

Developed countries have set seed industry as a new growth engine, which demands strong support from the government. Multinational seed companies such as Monsanto and DuPont have made huge financial investment to secure their major roles in the global market. To spur domestic seed industry performance, Korean government laid out the foundation for developing seed industry through policy promotion in the late 2000s. In this paper, I look at the current state of the domestic and international seed market to provide information for improving the efficiency of the propulsion of the Golden Seed Project (GSP) along with its vision. The increasing size of global giant companies has been regarded to monopolize the world seed industry wherein ten renowned companies occupy 73% of the overall global market. In effect, this causes a price hike due to limited seed choices. Domestic seed market has been stuck in a range due to a sustained low agricultural production resulting in decreased seed demand and market size. Though breeding technologies for rice and vegetables are world-class, the technologies for top global crops such as cabbage, paprika, and forage are insufficient therefore professionals in this field are not easily employed. Moreover, there is a lack in appropriate infrastructure set up in the universities which adds to ineffective training of professionals. Being a key-supporting industry for agriculture, seed industry should be granted with strong and sustainable investment support from the government. In view thereof, GSP, which started in 2012, ambitions to spur researches outlined by excellent professionals in universities and seed companies aimed to drive seed export volume and quality and attain domestic seed self-sufficiency through adoption of export- and import-substitution seed types (10 varieties each) development strategies. To develop Korea's seed industry excellent achievement of GSP's goals should be drawn successfully and to do this beside development of high quality seeds, support programs for promotion of seed exports are also needed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.4
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• pp.385-393
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• 2011

Soybean is the most promising crop for substituting rice on the paddy field. Excessive water stress is a common limiting factor in soybean yield under paddy soil condition. This study was carried out to identify changes in leaf total nitrogen and petiole ureide content under excess water conditions for establishing a screening system related to waterlogging tolerance. Waterlogging treatment was conducted by maintaining the water level on the soil surface for 10 days at the early vegetative growth stage ($V_5$) and the flowering stage ($R_2$). Leaf total nitrogen content, SPAD value and ureide content in petiole decreased in all soybean varieties in response to waterlogging, but the degree of decrease was much lesser in Pungsannamulkong and Muhankong than in Jangyeobkong and Myungjunamulkong, at 21 days after waterlogging treatment. This result means that root and nodule recovery rates were much higher in Pungsannamulkong and Muhankong than in Jangyeobkong and Myungjunamulkong after waterlogging treatment. The ureide and leaf nitrogen content showed high positive correlation with SPAD value, regardless of waterlogged stages. In conclusion, leaf nitrogen content, ureide content in petiole and leaf greenness were identified as promising indicator for screening soybeans which are tolerant of excess water.

• Korean Journal of Environment and Ecology
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• v.24 no.3
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• pp.249-257
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• 2010

The purpose of this paper is to weigh the possibility of endangered Jang-hang wetland at the estuary of Han River to be included on the Ramsar List of Wetlands of International Importance and come up with ways to manage the wetland depending on its biotope patterns. The target area is located between Gimpo bridge and Isanpo I.C. with about $2.7km^2$ area. Through the analysis of RIS(Information Sheet for Ramsar Wetlands), it was known that the wetland is located on the sedimentary topography and formed as a result of sediment at the estuary of the river owing to the concentration of rainfall during summer. The vegetation environment in the area is divided into brackish water and fresh water areas depending on salinity. Rhizosphere soil(RS) of the area was analyzed to be Silt loam while bottom RS to be Sand loam. The plant ecology was composed of 52 families 135 species and 11 varieties and 146 types. Among indigenous species found are Salix koreensis, Phragmites communis and Miscanthus sacchariflorus. The analyzed results of the actual vegetation showed that willow community accounts for 37% of the area and rice field is 13.5%. As for animal ecology, total of 62 species and 25,977 individual wild birds were observed. After comparing and analyzing the RIS we compiled with the Ramsar Site designation standards, it turns out that the Jang-hang wetland meets criteria 1(biographic region), criteria 2,3 and 4(species and ecological communities) and criteria 5 and 6(water birds). Thus, Jang-hang wetland is eligible for the Ramsar site. As a result of establishing and evaluating the biotope types for setting management areas, Jang-hang wetland has a total of 13 different types, and the grade I represents 75.4% of the area while the grade III 0.8% of the land status. We categorized four management zones for the wetland depending on the biotope patterns - preservation, restoration, use and buffer zones and suggested management methods for each zone.

• Journal of Biosystems Engineering
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• v.11 no.2
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• pp.31-40
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• 1986

Cylindrical and conical types of grain-straw separation equipment which has a stationary crimped sieve drum with rotating inner rotor were constructed. The developed equipments were tested to investigate the characteristics of separating performance under various mechanical conditions and crop conditions. As increase of the inclination of equipment and decrease of pitch of cover vane, the grain recovery was increased while straw rejection was decreased. The grain recovery and overall efficiency were decreased as the rotor speed and feeding velocity were increased for both varieties of rice, moisture contents, and test equipments. Conical prototype equipment performed higher straw rejection, lower grain recovery, and lower power requirement. However, separation performance of conical type equipment was more widely varied with various test conditions compared to cylindrical one. The performance of both equipments showed relatively insensitive to crop feedrate and crop properties, such as variety, moisture content, and grain-to-straw ratio.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.4
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• pp.29-41
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• 2015

Abandoned paddy field provides an excellent opportunity to improve the species diversity and habitat quality. Ecological characteristic on the changing of plant communities at different seral stages is a major basis data for ecological restoration. In this study, we investigated changes of the species composition and community indices on the plant community associated with abandonment of cultivated rice paddies. The ecological stability of the habitat was evaluated by using eco-floristic characters(Di; Disturbance index, AUI; Actual urbanization index). Survey sites were grouped into six stages(stageI (${\leq}3years$), stageII(3-5years), stageIII(5-7years), stageIV(7-10years), stageV(10-15years), stageVI(${\geq}20years$). Vegetation investigation was done from May 2009 to October 2012 and carried out phytosociological approach. The total flora were summarized as 176 taxa including 58 families, 127 genera, 157 species, 3 subspecies, 15 varieties and 1 forms. At each of successional stages, 64 taxa in stage I, 34 taxa in stage II, 84 taxa in stage III, 83 taxa in stage IV, 92 taxa in stage V, 23 taxa in stage VI were identified. Of the occurrence plants, the species with the highest r-NCD value were Alopecurus aequalis, Juncus effuusus var. decipiens, Persicaria thunbergii, Artemisia princeps, Salix koreensis and Alnus japonica at each stages. Herbaceous annual plants were dominated in the early stage, but its r-NCD value declined in the middle stage and the late stage. On the other hand, herbaceous perennial plants and Persicaria thunbergii, annual hydrophytes, increases in the middle stage. Woody plant and herbaceous plant which appeared in the forest edge increases in the late stage. Community indices correlate with successional stages. Richness and diversity index increase along the successional gradient. But dominance index decrease along the successional gradient. Evenness index was correlated with lower. In the ecological stability analysis of the habitat that evaluated by eco-floristic characters, stage I was the most unstable habitat. And the stability of the habitat has improved according to the successional stage.

• Korean Journal of Agricultural Science
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• v.4 no.1
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• pp.51-60
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• 1977

In order to determine ecological variations of flowering date and yields under the different seasonal cultures, and to select the higher yielding varieties which were adaptable to Korean climate, 100 mungbean cultivars were sown at the interval of 15 days from April 22 to July 21 in 1976. The results obtained are summarized as follows: 1. The number of days required to flowering from seeding were decreased by delaying the seeding date. 2. When accumulated temperature at first flowering from seeding were reached $945-1,126^{\circ}C$, the mungbean cultivars started to flower regardless of seeding dates. Especially, when mungbean was planted around standard planting date, the plants flowered for very short duration. 3. There were highly significant correlations between the number of days from seeding to flowering at each seeding date and standard planting date. 4. Yields per plant were tend to decrease with the delay of seeding date but there were no significant difference between seeding dates. Therefore, it appears that mungbean can be planted for longer period of time compared to other crops such as rice and soybean. 5. Highly significant correlations were found between the number of days of first flowering and yields per plant at most seeding dates. 6. It may be feasible to grow high yielding mungbean cultivars such as CES 140, LM 2100, LM 690, L 576 and LM 689 after harvesting of spring vegetables in May and before planting of fall vegetables.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.10
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• pp.1467-1474
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• 2012

The purpose of study was to introduce menus consisting of traditional local foods consumed in Busan, Korea. Five different types of formal meal menus with three side dishes and five different types of informal meal menus of which the main dish was not cooked rice were developed. Scores for the menu evaluations of formal and informal meals were higher than 7.9 (mean score of 6 category) on a 9.0 scale, suggesting that the menus were well constituted in terms of 'repeated use of ingredients and cooking methods', 'balance between main and side dishes', 'frequency of usage of local products', 'nutritional balance', 'variety of dishes', and 'popularization'. Nutritional values of menus were compared with those of the KDRI for men aged 30~49 years old. All ten menus reflected a low calorie, high protein, and high fiber diet. Mineral contents (Ca, Fe, Zn, K, and Na) of the above 10 menus were higher than those of the KDRI. On the other hand, vitamin contents slightly differed according to meal type due to limited fresh vegetable usage in the winter season. Vitamin A, B ($B_1$, $B_2$, niacin, $B_6$), C, folic acid, and E contents in the five informal menus were found to be proper or greater than those of the KDRI. However, for the formal meal menus, all vitamin contents except that of vitamin A in menu type I was lower than that of the KDRI. Content of vitamin C in menu type V was approximately 50% of that of the KDRI. The most preferred formal menu was consisted of Ogokbap, Boreumjijimi, Dongchimi, Namul (nine varieties), Gaksaeksanjeok (Shark/Daegu/Gunso), and Gimgui. And that for informal menu was consisted of Honghapjuk, Baechu kimchi, Dongchimi, Miyeokseolchi, Kodari jorim, and Neulgeun hobakjeon. Suggestions for providing more fresh vegetables or fruits for certain types of meals (formal meal type V) were offered. Additionally, pre-preparation of sea products were required to reduce Na contents.