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Prediction of Soil Erosion from Agricultural Uplands under Precipitation Change Scenarios (우리나라 강우량 변화 시나리오에 따른 밭토양의 토양 유실량 변화 예측)

  • Kim, Min-Kyeong;Hur, Seong-Oh;Kwon, Soon-Ik;Jung, Goo-Bok;Sonn, Yeon-Kyu;Ha, Sang-Keun;Lee, Deog-Bae
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.6
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    • pp.789-792
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    • 2010
  • Major impacts of climate change expert that soil erosion rate may increase during the $21^{st}$ century. This study was conducted to assess the potential impacts of climate change on soil erosion by water in Korea. The soil loss was estimated for regions with the potential risk of soil erosion on a national scale. For computation, Universal Soil Loss Equation (USLE) with rainfall and runoff erosivity factors (R), cover management factors (C), support practice factors (P) and revised USLE with soil erodibility factors (K) and topographic factors (LS) were used. RUSLE, the revised version of USLE, was modified for Korean conditions and re-evaluate to estimate the national-scale of soil loss based on the digital soil maps for Korea. The change of precipitation for 2010 to 2090s were predicted under A1B scenarios made by National Institute of Meteorological Research in Korea. Future soil loss was predicted based on a change of R factor. As results, the predicted precipitations were increased by 6.7% for 2010 to 2030s, 9.5% for 2040 to 2060s and 190% for 2070 to 2090s, respectively. The total soil loss from uplands in 2005 was estimated approximately $28{\times}10^6$ ton. Total soil losses were estimated as $31{\times}10^6$ ton in 2010 to 2030s, $31{\times}10^6$ ton in 2040 to 2060s and $33{\times}10^6$ ton in 2070 to 2090s, respectively. As precipitation increased by 17% in the end of $21^{st}$ century, the total soil loss was increased by 12.9%. Overall, these results emphasize the significance of precipitation. However, it should be noted that when precipitation becomes insignificant, the results may turn out to be complex due to the large interaction among plant biomass, runoff and erosion. This may cause increase or decrease the overall erosion.

Effect of Swine Liquid Manure on Soil Chemical Properties and Growth of Rice (Oryza sativa L.) (양돈분뇨 발효액비 시용이 토양 화학성과 벼 (Oryza sativa L.) 생육에 미치는 영향)

  • Lee, Kyu-Hoi;Yoo, Jae-Hong;Park, Eun-Ju;Jung, Yeong-In;Tipayno, S.C.;Shagol, C.C.;Sa, Tong-Min
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.6
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    • pp.945-953
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    • 2010
  • This study was conducted to evaluate the effect of swine liquid manure (SLM) on rice grown in Yeonggwang-gun in 2008. The treatments consisted of SLM and chemical fertilizer (CF) based on the recommended amount of nitrogen (11 kg N $10a^{-1}$). The Total N content of the SLM used was 2,881 mg $L^{-1}$. Plant height at the early stage of growth and tiller number were not significantly different between plots applied with swine liquid manure and those with chemical fertilizer in all areas. Plant height at the later stage of growth, lodging and yield were not significantly different between plots applied with swine liquid manure and those with chemical fertilizer in three areas (Baeksu, Gunnam, Beopseong). Plant height at the later stage of growth, as well as lodging were higher in SLM plots than in chemically fertilized plots in Yeonggwang and Yeomsan. However, grain yield was lower in SLM plots than in chemically fertilized plots in these areas. Soil organic matter content and exchangeable cations increased in the swine liquid manure applied plots. Moreover, heavy metal content did not increase in the plots treated with swine liquid manure. Further research to determine the suitable rate of swine liquid manure is needed to reduce lodging damage and to increase the yield and quality of rice.

Estimation of Carbon Emission and LCA (Life Cycle Assessment) from Pepper (Capsicum annuum L.) Production System (고추의 생산과정에서 발생하는 탄소배출량 산정 및 전과정평가)

  • So, Kyu-Ho;Park, Jung-Ah;Huh, Jin-Ho;Shim, Kyo-Moon;Ryu, Jong-Hee;Kim, Gun-Yeob;Jeong, Hyun-Cheol;Lee, Deog-Bae
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.6
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    • pp.904-910
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    • 2010
  • LCA (Life Cycle Assessment) carried out to estimate carbon footprint and to establish of LCI (Life Cycle Inventory) database of pepper production system. Pepper production system was categorized the field cropping (redpepper) and the greenhouse cropping (greenpepper) according to pepper cropping type. The results of collecting data for establishing LCI D/B showed that input of fertilizer for redpepper production was more than that for greenpepper production system. The value of fertilizer input was 2.55E+00 kg $kg^{-1}$ redpepper and 7.74E-01 kg $kg^{-1}$ greenpepper. Amount of pesticide input were 5.38E-03 kg $kg^{-1}$ redpepper and 2.98E-04 kg $kg^{-1}$ greenpepper. The value of field direct emission ($CO_2$, $CH_4$, $N_2O$) were 5.84E-01 kg $kg^{-1}$ redpepper and 2.81E+00 greenpepper, respectively. The result of LCI analysis focussed on the greenhouse gas (GHG), it was observed that the values of carbon footprint were 4.13E+00 kg $CO_2$-eq. $kg^{-1}$ for redpepper and 4.70E+00 kg $CO_2$-eq. $kg^{-1}$ for greenpepper; especially for 90% and 6% of $CO_2$ emission from fertilizer and pepper production, respectively. $N_2O$ was emitted from the process of N fertilizer production (76%) and pepper production (23%). The emission value of $CO_2$ from greenhouse production was more higher than it of field production system. The result of LCIA (Life Cycle Impact Assessment) was showed that characterization of values of GWP (Global Warming Potential) were 4.13E+00 kg $CO_2$-eq. $kg^{-1}$ for field production system and 4.70E+00 kg $CO_2$-eq. $kg^{-1}$ for greenhouse production system. It was observed that the process of fertilizer production might be contributed to approximately 52% for redpepper production system and 48% for greenpepper production system of GWP.

Differences of Nutrient Input by Throughfall, Stemflow and Litterfall between Deciduous Forest and Larix kaempferi Plantation in Mt. Joonwang, Kangwon-do (강원도 중왕산 지역 낙엽활엽수림과 낙엽송 조림지에서 수관통과우와 수간류 및 낙엽낙지에 의한 양분 유입의 차이)

  • Jung, Mun-Ho;Lee, Don-Koo;Um, Tae-Won
    • Korean Journal of Soil Science and Fertilizer
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    • v.40 no.2
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    • pp.136-144
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    • 2007
  • The objectives of this study were to compare nutrient input by throughfall, stemflow and litterfall and concentration of nutrient in soil water between deciduous forest stand and Larix kaempferi plantation at Mt. Joongwang, Pyongchang-gun, Gangwon-do. The amount of rainfall interception during study period in deciduous forest stand and L. kaempferi plantation was 12% and 36%, respectively. Concentrations of cation ($Na^+$, $Mg^{2+}$, $K^+$ and $Ca^{2+}$) in throughfall were not different, while concentration of $Cl^-$ in stemflow was higher in L. kaempferi plantation. The results indicated that annual nutrient inputs by rainfall with the exception of $Cl^-$ were significantly greater in deciduous forest stand. In soil water, concentrations of anion ($Cl^-$, $NO_3{^-}$ and $SO{_4}^{2-}$) in A-layer, and $Ca^{2+}$ and $Cl^-$ in B-layer were higher in L. kaempferi plantation. Litterfall input during study period was $2,589kg\;ha^{-1}$ in deciduous forest stand and $1,046kg\;ha^{-1}$ in L. kaempferi plantation. Concentration of N was higher in L. kaempferi plantation, while N input from litterfall was greater in the deciduous forest stand ($36.81kg\;ha^{-1}yr^{-1}$) than L. kaempferi plantation ($16.16kg\;ha^{-1}yr^{-1}$). $Na^+$, $Mg^{2+}$, $K^+$ and $Ca^{2+}$ in litterfall collected from deciduous forest stand were found to be higher than those from the L. kaempferi plantation. Also, input of those were greater in deciduous forest stand. Thus, total nutrient input by throughfall, stemflow and litterfall was greater in deciduous forest stand than L. kaempferi plantation, significantly.

Effect of Irrigation Amounts on Growth and Yield of Rice in Desert Climates (인공사막환경에서 벼 재배시 관개량에 따른 생육 및 수량 특성 변화)

  • Jung, Ki-Youl;Lee, Sang-Hun;Jeong, Jae-Hyeok;Chun, Hyen-Chung;Oh, Seung-ka;Jeon, Seung-ho
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.66 no.3
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    • pp.201-209
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    • 2021
  • There is a growing interest in rice cultivation on farms with irrigation facilities in desert climates. We investigated the growth characteristics and yields of two rice cultivars (FL478 and Asemi) irrigated at field capacities (FCs) of 80%, 100%, and 120% in a lysimeter with coarse sandy soils. The results showed that at the heading stage, the FC 100% treatment had the highest plant height and number of tillers between the two cultivars. At the harvest period, the culm and panicle lengths of both cultivars at FC 100% were similar to those of the control. In contrast, the number of panicles, grain number per panicle, and percentage of ripened grains were the highest in the control. Moreover, FL478 and Asemi had the highest grain yields of 1.40 and 2.20 kg·pot-1 in the control, respectively. For both cultivars, the grain yields of the FC 100% and FC 120% treatments were approximately 70% of the control. In comparison, FL478 and Asemi had the highest water productivity of 0.45 and 0.63 kg·m3-1 for the FC 80% treatment, followed by the FC 100% treatment (0.42 and 0.59 kg·m3-1, respectively), which was nearly 14.3% and 20.3% higher than that of the control. Therefore, we found that irrigation at FC 100% is anticipated to be effective in managing surface drip irrigation for rice cultivation in desert climates in arid environments, while maintaining rice yields.

A Study on the Oxy-Combustion of the Coal in Drop Tube Furnace (Drop Tube Furnace에서 석탄의 순산소 연소 특성)

  • Roh, Seon Ah;Yun, Jin Han;Lee, Jung Kyu;Keel, Sang In;Min, Tai Jin;Kim, Sang-Bok;Park, In-Yong;Han, Bangwoo;Kim, Jin-Tae
    • Clean Technology
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    • v.27 no.4
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    • pp.367-371
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    • 2021
  • The oxy-combustion system is one of the carbon recovery and storage technologies (CCS: Carbon capture & storage) that performs coal combustion using pure oxygen and recirculated flue gas. This is a technology that facilitates storage of carbon dioxide by generating an exhaust gas consisting of only carbon dioxide without a process of separating carbon dioxide and nitrogen when coal is burned using pure oxygen and recirculated flue gas mixture instead of a conventional air combustion system that produces carbon dioxide and nitrogen mixed exhaust gas. In this study, the characteristics of generated NO and SO2 as atmospheric pollutants during oxy-combustion were examined using O2/CO2 mixed simulation gas. The reaction temperature was varied from 900 ℃ to 1200 ℃ and oxygen partial pressure was varied from 30% to 50%. The results showed that NO and SO2 concentrations in flue gas increased as the oxygen concentration and the reaction temperature in the furnace increased. The partial pressure of CO2 in flue gas also increased as the oxygen concentration and the reaction temperature in the furnace increased. As a results of comparing NO production of 30% O2/CO2 oxy-combustion with air combustion, NO in flue gas increased with reaction temperature in both experiments and NO of oxy-combustion was 40 ~ 80 ppm lower than that of air combustion.

Effects of Entrepreneurial Competencies on Entrepreneurial Satisfaction and Life Satisfaction: Moderator Effect of Person-Job Fit (창업가역량이 창업만족도와 삶의 만족도에 미치는 영향: 직무적합도의 조절효과 검증)

  • Lee, Sung Ho;Nam, Jung Min
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.16 no.4
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    • pp.85-99
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    • 2021
  • Due to the continuous unemployment problem, the number of jobs is gradually decreasing, and entrepreneurship is emerging as an alternative. This is because, despite the government operating various start-up support programs to build a start-up-friendly culture, young entrepreneurs cannot endure the valley of death and disappear. Therefore, through this study, we intend to provide implications by analyzing the impact on Entrepreneurial satisfaction, which is essential for continuously running a business, and life satisfaction, which can act as a social awareness. This study was conducted with 573 non-wage workers who belonged to the founders among the participants of the 'College Graduation Occupational Migration Path Survey(GOMS)' survey provided by the Korea Employment Information Service. In order to analyze the relationship between entrepreneurial competency and job fit, Entrepreneurial satisfaction, and life satisfaction, the analysis was conducted using the SPSS 23.0 program. The main research results are summarized as follows. First, entrepreneurial competency has a positive effect on Entrepreneurial satisfaction and life satisfaction. Second, job fit indicates a moderating role in the relationship between entrepreneurial competency and Entrepreneurial satisfaction. Third, start-up satisfaction appears to have a partial mediating role in the relationship between entrepreneurial competency and life satisfaction. Fourth, as a result of analyzing the difference between groups according to the type of start-up(single/partnership), the group that worked together showed higher Entrepreneurial satisfaction and life satisfaction. The main implications of this study are: First, in order to increase the Entrepreneurial satisfaction and life satisfaction of university graduates who are the subject of the study, it will be necessary to design a program that can diagnose and enhance the entrepreneurial competency of students at the university level. Second, entrepreneurial competency is a basic intrinsic factor that founders must have, and it should act as an important evaluation factor when selecting founders for support programs from start-up support organizations as well as founders. Third, it is necessary to maintain mutual trust by documenting problems (positions, wages, management rights, distribution of profits, etc.) that may occur in joint ventures with objective data. Fourth, it is necessary to establish an environment in which the MZ generation, armed with the challenging spirit and creativity, can continue to take on challenges even if they fail.

Mediating Effect of Opportunity Recognition Among Entrepreneurial Alertness, Mentoring, & Number of Mentoring on New Ventures' Performance (기업가적 기민성과 멘토링 및 멘토링 횟수와 기업성과 관계에서 기회인지의 매개효과 영향)

  • Park, Mi-Jung;Lee, Seon-Ho;Hwangbo, Yun
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.16 no.4
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    • pp.1-24
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    • 2021
  • The Korean government is currently expanding the business startup incubator support program and funds for new ventures with innovative technology in order to spread the second venture boom. However, despite the fact that entrepreneurial education and mentoring that entrepreneurs should have are important parts for the sustainable growth of the startup, some companies selected for government support programs are reluctant to participate in programs such as entrepreneurship education and mentoring for the sole purpose of funding commercialization. This research addressed the effects of entrepreneurial alertness with opportunity awareness as its medium and the small business mentoring service along with the number of times the mentoring has taken place, on the corporate performances. The results of empirical research are as follow: the first one is that scanning-search and evaluation-judgment can influence a company's performance (financial, non-financial) through opportunity recognition, with the exception of association-connection, which is a sub-factor of entrepreneurial alertness. Secondly, it was found to affect a company's financial and non-financial performance through opportunity recognition for financing mentoring, technical support mentoring, and management support mentoring. Thirdly, it was found that the number of mentoring also affects the financial and non-financial performance of a company through opportunity recognition. The implications of this study are that it should be revisited that program managers consider rooms that do not violate the startup founder's strategic decision-making opportunities when designing and operating the program as entrepreneurial alertness sub-factor association-connection does not affect corporate performance through opportunity recognition. This study also emphasizes the need for customized mentoring to meet the outcome goals of each startup, as it has been empirically clarified that the mentoring provided to the startup by the government's support is important. The contribution of this research is that entrepreneurial alertness and opportunity recognition that are treated as important components in research for entrepreneurship, and the factors of mentoring and mentoring frequency that are recognized as important elements in the practical aspect of startup business are clarified theoretically and empirically as an influential factor in corporate performance. And this study also provide a rationale for the startup business support agency supplying mentoring.

Effect of the Elevated Carbon Dioxide on the Growth and Physiological Responses of Peach 'Mihong' (CO2 상승처리가 복숭아 '미홍'의 수체생육 및 생리반응에 미치는 영향)

  • Lee, Seul Ki;Cho, Jung Gun;Jeong, Jae Hoon;Ryu, Suhyun;Han, Jeom Hwa;Do, Gyung-Ran
    • Journal of Bio-Environment Control
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    • v.30 no.4
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    • pp.312-319
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    • 2021
  • This study was conducted to investigate the effect of elevated carbon dioxide on the growth and physiological responses of peach 'Mihong' (Prunus persica). We simulated three different carbon dioxide conditions based on climate change scenarios RCP 8.5 in the sunlight phytotron rooms from April 22 to July 6, 2020; 400 µmol·mol-1(present condition), 700 µmol·mol-1 treatment(expecting carbon dioxide concentrations in mid-21st century), 940 µmol·mol-1 treatment (expecting carbon dioxide concentrations in late 21st century). The average of maximum photosynthesis rate at 700 µmol·mol-1(16.06 µmol·CO2·m-2·s-1) was higher than those at 400 µmol·mol-1(14.45 µmol·CO2·m-2·s-1) and 940 µmol·mol-1(15.96 µmol·CO2·m-2·s-1) from May 22 to July 2. However, stomatal conductances at 700 µmol·mol-1 and 940 µmol·mol-1 were lower than those at the control. Also, the carbon dioxide saturation point in all treatments was reduced from 1,200 µmol·mol-1 in the early stage of growth to 600-800 µmol·mol-1 in the late stage of growth. The stomatal densities were decreased as carbon dioxide increased. The shoot lengths were decreased while the carbon dioxide was increased, but the increase of trunk diameter and leaf areas, shoot numbers were not statistically different. The fruit weight at 700 µmol·mol-1(152.5 g) was higher than those at the control(141.8 g) and 940 µmol·mol-1(147.4 g). The soluble solids were higher at 700 µmol·mol-1, 940 µmol·mol-1 compared to the control. These results suggest that a carbon dioxide elevated to 700 µmol·mol-1 in the future may give a positive effect on the yield and fruit quality of peach 'Mihong' while a carbon dioxide elevated above 940 µmol·mol-1 may affect negatively such as early senescence and loss of fruit set.

Distribution of Flora and Naturalized Plants in Gwangpo Bay, Sacheon (사천시 광포만의 식물상 및 외래식물 분포)

  • Lee, Min-Sook;Kim, Jung-Soo;Park, Sam-Bong;Cho, Gab-Ja;An, Jong-Bin;Song, Jin-Heon;Kwag, Chil-Sig;Kim, Bong-Gyu;Choo, Gab-Chul
    • Journal of Korean Society of Forest Science
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    • v.110 no.3
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    • pp.369-392
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    • 2021
  • This study aimed to provide basic data for efficient flora management of vascular plants, halophytes, and naturalized plants in the Gwangpo Bay area in Sacheon city, Gyeongsangnam-do. The flora found in this area incorporated 520 taxa, including 93 families, 299 genera, 466 species, 3 subspecies, 41 varieties, and 10 forma, and accounted for approximately 10.6% of total vascular plants (4,884 species) in Korea. According to the survey, 76 species of Gramineae showed the highest frequency (14.6%), followed by 67 species of Compositae (12.8%), 34 species of Leguminosae (6.5%), 27 species of Cyperaceae (5.2%), and 22 species of Rosaceae (4.2%). Rare plant species designated by the Korea Forest Service were categorized into six taxa, including three taxa in the LC grade, one taxon in the CR grade, one taxon in the VU grade, and one taxon in the EN grade. Korea endemic plants belonged to nine taxa consisting of seven families, seven genera, and nine species. The special floristic plants included 44 taxa, including one taxon (Prunus yedoensis) in the V grade, four taxa in the IV grade, ten taxa in the III grade, six taxa in the II grade, and 23 taxa in the I grade. Naturalized plants included 62 taxa consisting of 15 families, 47 genera, 59 species and 3 varieties. Halophytes consisted of 27 taxa, including 13 families, 24 genera, 24 species, 2 varieties, 1 forma, which consisted of Atriplex gmelinii, Suaeda glauca, Suaeda maritima, and Lathyrus japonicus. Invasive alien species in the Gwangpo Bay area included seven taxa. Since Ambrosia artemisiifolia, Sicyos angulatus, andPaspalum distichum var. indutummay have harmful effects on native plants, these plants must be artificially controlled.