• Horticultural Science & Technology
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• v.32 no.5
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• pp.739-743
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• 2014

This work characterizes 'Yeolha', a new strawberry (Fragaria ${\times}$ ananassa Duch.) cultivar that was released by the Highland Agriculture Research Center, RDA, in 2013. This cultivar originated from a 2008 cross between 'Goha' and 'Elsinyo' and showed excellent ever-bearing characteristics including continuous a flowering habit under long-day and high temperature conditions. It was originally named 'Saebong No. 5' after examining its characteristics and productivity in summer culture from 2010 to 2013. After two regional adaptability tests in 2012, it was selected as an elite cultivar and renamed 'Yeolha'. The general characteristics of 'Yeolha' include a semi-spreading plant type, elliptic leaves, and strong vigor in growth. Its fruit is conical and red. T he s oluble s olids content of 'Yeolha' is 8 .6%, w hich is 0.6% h ig her than t hat of 'Flamenco', b ut f ruit hardness is lower than that of 'Flamenco'. The average fruit weight of 'Yeolha' is about 12.1 g and the marketable yield is $28,133kg{\cdot}ha^{-1}$, which is 117% higher than that of 'Flamenco'. 'Yeolha' is resistant against Fusarium wilt. In addition, 'Yeolha' is suitable for four-season cultivation as a high harvesting cultivar because it shows continuous flowering under long-day and high temperature conditions.

• Applied Biological Chemistry
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• v.29 no.2
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• pp.175-181
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• 1986

Eightyseven strains of indigenous Rhizobia were isolated from the nodule of soybean cultivar, Danyup, cultivated in four different soils sampled from continuously soybean cultivated and newly reclaimed fields. The strains were grouped into Bradyrhizobium japanicum (slow-grower:55 strains) and Rhizobium fredii (fast-grower: 32 strains). The both groups could be divided into two sub-groups according to the denitrification characteristics, that is, denitrifying fast-grower (F-I), nitrate respiring fast-grower (F-II), denitrifying slow-grower (S-I). and nitrate respiring slow-grower (S-II). Among the 87 isolates, F-I, F-II, S-I and S-II sub-groups were 10, 22, 48 and 7 strains, respectively. The one-and two-dimensional polyacrylamide gel electrophoretic pattern of the four sub-groups were compared and discernible difference was observed between fast and slow-grower, but the difference was not discernible between subgroups within the same growth rate group.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.2
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• pp.65-69
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• 2009

We studied to compare the fractionation patterns of Ni, Cu, Zn in Jeju volcanic ash soils and to elucidate the uptakes of them by Pakchoi(Brassica campestris var. chinensis). Fractionation patterns of soils by sequential extraction method were different and make to distinguish from various soil types. In Pakchoi, the transfer rates of Ni, Cu, Zn from root to shoot were also different by metal types. There are low corelation between fractional contents in soil and contents in plants of trace elements except for exchangeable Zn. It is needed to develop novel methods for the assessment soil Ni in relation to plant uptake because of poor corelation.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.261-267
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• 1999

Pot experiments were conducted to evaluate the phosphorus (P) availability with cropping in soils where P were highly accumulated. Bray 1-P contents of the used three soils were 584, 695 and $1043P\;mg\;kg^{-1}$, respectively. Corn ${\rightarrow}$ Chinese cabbage ${\rightarrow}$ Chinese cabbage ${\rightarrow}$ corn were sequentially grown from 1996 to 1998. P fertilizer was applied at three levels of 0 (P0), recommended application rate (P1), and double of recommended application rate (P2). At the end of each crop growth, available P content was determined by methods of Bray 1-P, Olsen-P and Lancaster-P. The growth of crops were not significantly affected by the rates of P applications. The relative yields of PO treatment were more than 88% of P1 treatment. The recoveries of added phosphorus were relatively low due to the high content of available phosphorus in soils. Although available phosphorus contents decreased through cropping, the concentration of soil available phosphorus was maintained high level even after the final cropping. In the case of P0 treatment in the three soils, the residual concentration was in the range of $410{\sim}610mg\;kg^{-1}$ for Bray 1-P, $284{\sim}410mg\;kg^{-1}$ for Olsen-P and $368{\sim}524mg\;kg^{-1}$ for Lancaster-P. The amount of soil available phosphorus decreased during the experiments was linearly regressed with high significance to the amount of P taken up by crops. The regressions of soil 1 as follow, Bray 1-P : y=149.7x=102.7, Lancaster-P : y=209.2x-140.2, Olsen-P: y=60.8x=19.9. The decrease rate of available phosphorus in the P0 treatment with cropping was described by an equation of first-order chemical reaction. The equation of soil1 was as follow: Bray 1-P: In(C)= -0.12N + 6.96 r=-0.991, Lancaster-P: In(C)= -0.14N = 6.88 r= -0.938, Olsen-P: In(C)= -0.07N = 6.37 r= -0.959. The rate constants seemed to be affected by ply, sand and silt content, and exchangeable $Ca^{2+}$ concentration. The times of cropping needed to reduce the content of available P to half of the initial or to the index level could be predicted by using that equation.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.11
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• pp.1154-1160
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• 2008

Changes of zinc speciation and dehydrogenase activity in soil were studied before and after a field scale phytoextraction by Fagopyrum esculentum at a paddy soil near a closed zinc mine. The concentrations of zinc in paddy soil, in which Fagopyrum esculentum was planted, ranged from approximately 600 mg/Kg(high Zn soil) to 300 mg/Kg(moderate Zn soil). Despite of severe growth inhibition by Zn at the high Zn region, Fagopyrum esculentum accumulated phytoavailable fraction of Zn absorbed from the soil, and enhanced soil dehydrogenase activity (DHA) that had been inhibited by Zn toxicity. After the plant cultivation of 2 months, the concentrations of phytoavailable Zn in the rhizosphere soil at high and moderate Zn region has decreased 25% and 75%, respectively. The amount of Zn reduction in the rhizosphere soil corresponds to that accumulated in plants (recovery 92$\sim$107%), which implies Fagopyrum esculentum removed Zn from the soil. DHA was inversely correlated to the total Zn concentrations in soil. Before plant cultivation, the DHA in the high Zn soil was twice lower than that in the moderate Zn soil. More than 35% of DHA increase was observed in both soils after the application of phytoextraction with Fagopyrum esculentum.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.3
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• pp.314-322
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• 2008

This study was carried out to assess aerobic stabilized waste sludge as liquid fertilizer for the growth of cucumber, cabbage and chrysanthemum. Sludge was pretreated with NaOH(40 meq/L) at 40$^{\circ}C$ for 330 min. The number of fecal coliforms in batch test sludge fertilizer was more efficiently reduced than those in continuous one, maybe due to longer SRT. All produced fertilizer belonged to class B according to US EPA requirement at least. Among 6 heavy metals regulated in Korea, As, Cd and Hg were not detectable in plant amended with fertilizer whereas the concentration of Cr, Cu and Pb in plant was less than 10 mg/kg dw. However, Zn and Ni, which were restricted in other country, but not in Korea, were detected in most amount of 118 mg/kg and 15.7 mg/kg, respectively. Furthermore, based on dry weight of plant, digested sludge(5.4 mg, dw) functioned as better fertilizer rather than activated sludge (4.3 mg, dw), much more fertile when those sludge was pretreated(1.24 mg, dw) compared to untreated one(1.12 mg, dw). But its fertility was 60$\sim$80% of commercial fertilizer and accumulation of Zn, Ti and Cr in plant was founded. Therefore, it could be concluded that sludge-fertilizer can be used for flower unlimitedly, but for edible plant limitedly as additive fertilizer.

• Korean Journal of Organic Agriculture
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• v.20 no.4
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• pp.503-518
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• 2012

Korean type of no-tillage cultivation method which was applied on this study used the ridge and the furrow and constantly recycling them as it was suitable for Korea's weather and farming conditions. This no-tillage cultivation was reported to have little negative impact such as reduction of production (Kwon et al., 1997). In addition, it was found to have a lot of benefits as it requires less agro-materials and energy costs as well as shortened working hours because tillage operation is not needed. (Yang et al., 2012). According to an analysis, no-tillage cultivation can reduce greenhouse gas emissions by $344.7kgCO^2$ (58%) in every 10a ($1,000m^2$) compared to ordinary pepper farming technique (Korea averages). Direct-indirect reduction effects from using fertilizer and using less amount of energy were 92% and 44% respectively both of which can be considered very high. Besides the direct effects of no-tillage cultivation, soil management using no-tillage technique raises carbon sequestration effect on soil as time goes on (West & Marland, 2002), that is why the technique is expected to have constant carbon emission reduction effect. For theses reasons, distribution and expansion of Korean type no-tillage cultivation are expected to play a role as major agro-green technologies for achieving our goal of reducing greenhouse gas emissions in agricultural sector.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.273-281
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• 2013

Based on the results of continuous flux measurements at the Gimje paddy flux site in the southwestern coast of Korea, carbon dioxide and energy exchanges between customarily cultivated rice-barley double cropping paddy field and the atmosphere during the 2012 rice growing season (from $9^{th}$ Jun. 2012 through $20^{th}$ Oct. 2012) were analyzed. Carbon dioxide and energy (H, LE) fluxes were estimated by the eddy covariance method. Environmental parameters (net radiation, precipitation, etc.) and plant biomass (LAI, plant height, etc.) were measured along with fluxes. After the quality control and gap-filling, the observed fluxes were analyzed. The results have been showed that net ecosystem exchange (NEE), gross primary production (GPP), and ecosystem respiration (Re) during the rice cropping period were -277.1, 710.3, and 433.2 g C $m^{-2}$, respectively.

• Research in Plant Disease
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• v.16 no.2
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• pp.141-147
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• 2010

Resistance to Phytophthora blight (Phytophthora capsici Leonian) of commercial cultivars of Capsicum pepper in Korea were evaluated from 2008 to 2010. In 2008 and 2009, the cultivars were tested for resistance to the Pc003 isolate collected in Youngyang, Gyeongbuk province. In 2010, the selected cultivars in the previous years were tested by inoculating with 3 isolates obtained from the pepper plants in Miryang in Gyeongnam province, Youngyang in Gyeongbuk province, and Goesan in Chungbuk province. A continuous variation in resistance from highly resistant to susceptible was observed among the commercial pepper cultivars. It was also noted that some cultivars, although their names were initiating with 'Yeokgang' or 'PR' meaning Phytophthora resistance, were very low in resistance or susceptible. When the resistant cultivars selected in 2008 and 2009 experiment were inoculated with the 3 isolates, all the commercial cultivars except a rootstock, 'Tantan', succumbed to the exceptionally virulent Pc005 (Miryang) isolate. Pc002 (Goesan) was a little more virulent than Pc003 (Youngyang). A few cultivars resistant to Pc003 (Youngyang) were severely infected by Pc002 (Goesan). Significant interaction in analysis of variance suggested the differential interactions between cultivars and pathogen isolates. Strategies to breed cultivars having high level of resistance to the highly variable pathogenic fungus, Phytophthora capsici, were discussed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.564-570
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• 1997

Field experiments were carried out to investigate the effects of different residue treatment of vetch sward on soil improvement, rice growth and grain yield from 1995 to 1996. With Chinese milkvetch, pH, Ca, and Mg of paddy soil were increased in subsoil(10~20cm soil depth), and organic matter, P$_2$ $O_{5}$, and K were increased in top soil (0~10cm soil depth). Redox potential of the paddy soil with milkvetch residue was severely reduced at earlier flooding period, and recovered gradually as rice growth continued. Weeds were more abundant in the paddy with unchanged vetch stand. The most dominant weed species in the paddy soil with vetch sward residue was Echinochloa crus-galli, followed by Leersia japonica, Polygonum hydropiper in the order of abundance. Seedling establishment ratio of rice directly sown over vetch-sward was lower than in conventional tillage paddy(no-vetch, tilled) condition. Rice growth pattern, however, was not significantly affected by vetch sward treatments. The number of tillers per square meter and plant height at heading date were not significantly different among the vetch-sward treatments. Grain yield was the highest in plough of vetch vegetation, followed by conventional (no-vetch, tilled), live-mulching of vetch, vetch-removed, and vetch-desiccated by weedcide. The whole grain rice yield was the lowest in vetch-desiccated by weedcide.