• Korean Journal of Soil Science and Fertilizer
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• v.38 no.3
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• pp.157-163
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• 2005

The increasing of greenhouse gases may change agricultural environment. The agronomic productivity will depend upon change of temperature, precipitation, solar radiation and fertilization. Particularly, nitrogen fertilization considerably influences rice productivity and agricultural environments. This experiment was conducted to study transformation of nitrogen and to determine the primary yield components responsible for yield differences in paddy soil. $NH_4-N$ concentration of NPK plot in surface water of paddy soil was $2.07mg\;L^{-1}$ at 5 days after transplanting, and then was decreased sharply due to rice absorption and loss to environment. $NO_3-N$ concentration of NPK plot in surface water was $3.97mg\;L^{-1}$ at 10 days after transplanting. $NO_3-N$ concentration range of CRF plot in surface water was $3-5mg\;L^{-1}$ at 30th after transplanting. The accumulation of $NH_3$ volatilization in NPK plot was $22.39kg\;ha^{-1}$, which accounted for 20% of N fertilizer applied but using of CRF fertilizer can reduce $NH_3$ volatilization by 67% in paddy soil. Use efficiency of N fertilizer was not different between CRF70% and CRF100% plot. Rate of N use efficiency were 27.4%, 51.2%, 49.0% in paddy field NPK, CRF70% and CRF100% plots respectively. The yield of CRF70% showed the best effect with 9.3% increase production ratio, compare with NPK plot.

• Journal of Korean Academy of Nursing Administration
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• v.1 no.1
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• pp.132-146
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• 1995

Even though Korean medical law stipulates that number of patients attended by a nurse is 2.5 for hospitalization and 30 for ambulatory care, the number of patients cared by a nurse per day is much greater than the standard prescribed by the medical law. Current productivity of nurses is not desirable unless the quality of care is considered. And nursing manpower staffing based on neither current nurses' productivity nor standard of medical law cannot respond properly to dynamic situation of the medical services. Under this background, the necessity of more efficient management of nursing manpower occupying 1/3 of total hospital workers has been recognized by many nursing administrators. Many nursing researchers have studied to foretell the nursing manpower objectively on the basis of measured nursing workload according to patient classification as well. Most of These researches, however, have been conducted in the tertiary hospitals, so it is imperative to conduct other researches to predict necessary nursing manpower in the secondary and the primary hospitals. The study was performed to measure nursing workload and predict pertinent nursing manpower to a secondary hospital with 400beds. Nursing workload was surveyed using measuring tool for direct and indirect care hours in a surgical unit and a medical unit. Survey was conducted from Sep.10 to Sep.16 and from Oct.5 to Oct.11, 1994 respectively by two skilled nurses, Subjects were patients, patients' family members and nursing personnels. Results are follows : 1. Patient classification distributed as 22% of class I (mildly ill patient), 57% of class II (moderately ill patient), and 21% of class III (acutely ill patient) in the medical nursing unit, while 23% of class I, 29% of class II, 12% of class III, and 36% of classIV (critically ill patient) in the surgical nursing unit. There was no difference of inpatient number between weekday and weekend. Bed circulation rate was 89% in both units and average patients number per day was 37.4 (total 42beds) in the medical nursing unit, 32.9 (total 37beds) in the medical nursing unit. 2. Direct care hours per day measured as 2.8hrs for class I, 3.3hrs for class II, and 3.5hrs for class III in the medical nursing unit, while 3.1hrs for class I, 3hrs for class II, 2.7hrs for class III, and 2.2hrs for classIV in the surgical nursing unit. Meanwhile, hours for nursing assistant activities per patient by patients' family members were 11mins and 200mins respectively. Direct care hour rate by shift was day 36%, evening 25%, and night 39% in the medical nursing unit, while 40%, 29%, and and 31% respectively in the surgical nursing unit. 3. Measurement and observation activity held 44.2% of direct care activities of nurses and medication 36.7%, communication 11.7%, exercise 1.8%, treatment 1.3%, hygiene 1.3%, elimination and irrigation 1.1%, suction 1%, nutrition 0.5%, thermotherapy 0.3%, oxygen therapy 0.1% in order. 4. Indirect care hours per day were 294.2mins in the medical nursing unit, and 273.9mins in the surgical nursing unit. By shift, evening was the highest in both units. Indirect care hours for each patient were 44.5mins in the medical nursing unit and 46mins in the surgical nursing unit. 5. checking activities including doctor's order, medication, and delivering patients to the next shift occupied 39.7% of indirect care activities, and preparation 26%, recording 23.8%, communication and conference 6.7%, managing equipments 2.1%, messenger activity 1.7% in order. 6. On the ground of these results, nursing manpower needed in a secondary hospital was estimated ; 27 nursing personnels for the medical nursing unit of 37beds, and 20 nursing personnels for the surgical nursing unit of 33beds.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.166-172
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• 2019

BACKGROUND: Increase in the ratio of small berries in blueberry production decreases the farmers' profits due to weakening market competitiveness and lowering harvest efficiency. One of the reasons for increased small berries is over fruit-load. For improving productivity and competitiveness of blueberry in Korea, hand-thinning can be applied to increase fruit quality before the developing adequate chemical thinning methods. This study was conducted to investigate the proper timing and methods for floral buds thinning in rabbiteye blueberry. METHODS AND RESULTS: Eight years old bushes of rabbiteye bluberries 'Brightwell' as a primary cultivar and 'Powderblue' as a pollinizer were used for this study. Fruit size distribution by leaf-to-fruit ratio was investigated by counting the number of leaves and fruits in canes of 127 'Brightwell' plants whose fruit set varied. Fifty percent of flowers/floral buds were removed in four different floral buds stages such as bud swell, late pink bud, full bloom, and petal fall, and the consumed time for thinning and fruit characteristics were recorded to investigate the effect and proper timing of floral buds thinning. Fruit weight and soluble solids content tended to increase in proportion to leaf-to-fruit ratio and the production of the number of fruits less than 13 mm in diameter decreased when leaf-to-fruit ratio was more than 2.5. Manual floral buds thinning by hands was fastest in full bloom stage and slowest in bud swelling stage. In all cultivars, fruit size was significantly smaller in non-thinning treatment than thinning, and there was, however, no significant difference in total fruit yield. The number of fruits less than 13 mm in diameter increased in both cultivars as floral buds thinning was delayed. Consumed time for picking 90% berries out of total berries per bush was shortest in full bloom stage thinning in 'Brightwell' and bud swelling, full bloom thinning in 'Powderblue'. These were 25 and 20 days faster than no thinning, respectively. CONCLUSION: Although the effect of floral buds thinning varied depending on the cultivars, our results confirmed that floral buds thinning was effective for the early intensive harvesting and the increase of the large fruit ratio and the harvesting productivity. Also, in order to increase thinning efficiency, it is recommended to remove the flower buds before the full bloom stage.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.235-250
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• 2021

The overarching question of this study is how a typical rice cultivation system in Gimje, Korea was keeping up with the triple-win challenge of climate-smart agriculture (CSA). To answer this question, we have employed (1) quantitative data from direct measurement of energy, water, carbon and information flows in and out of a rice cultivation system and (2) appropriate metrics to assess production, efficiency, GHG fluxes, and resilience. The study site was one of the Korean Network of Flux measurement (KoFlux) sites (i.e., GRK) located at Gimje, Korea, managed by National Academy of Agricultural Science, Rural Development Administration. Fluxes of energy, water, carbon dioxide (CO₂) and methane (CH₄) were directly measured using eddy-covariance technique during the growing seasons of 2011, 2012 and 2014. The production indicators include gross primary productivity (GPP), grain yield, light use efficiency (LUE), water use efficiency (WUE), and carbon uptake efficiency (CUE). The GHG mitigation was assessed with indicators such as fluxes of carbon dioxide (F_CO2), methane (F_CH4), and nitrous oxide (F_N2O). Resilience was assessed in terms of self-organization (S), using information-theoretic approach. Overall, the results demonstrated that the rice cultivation system at GRK was climate-smart in 2011 in a relative sense but failed to maintain in the following years. Resilience was high and changed little for three year. However, the apparent competing goals or trade-offs between productivity and GHG mitigation were found within individual years as well as between the years, causing difficulties in achieving the triple-win scenario. The pursuit of CSA requires for stakeholders to prioritize their goals (i.e., governance) and to practice opportune interventions (i.e., management) based on the feedback from real-time assessment of the CSA indicators (i.e., monitoring) - i.e., a purpose-driven visioneering.

• Journal of the Economic Geographical Society of Korea
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• v.25 no.1
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• pp.109-130
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• 2022

The Vietnamese government has proposed contract farming through a new type of cooperative as an institutional innovation which aims to restructure the agricultural sector. However, policy changes often impact farmers, who bear the primary effects of the transition process. Understanding households' strategies for land use and livelihood is crucial for policymaking in the agricultural development field. This study was conducted in the rural Binh Dao commune in Central Vietnam. We analyzed household members' labor force changes and their livelihood behaviors after their participation in a contract farming scheme using qualitative analysis methods combined with geographic information system (GIS) support, based on secondary data and in-depth interviews of 190 farmers. Simultaneously, we created a digital map of the cooperative's production area to investigate changes in land use and production activities. The findings show that contract farming shaped the vertical coordination of the value chain from the farmers to the cooperative and agricultural product trading companies. Subsequently, it encouraged land use and labor efficiency due to mechanical support. In addition, it also increased productivity and protected farmers from market risks. However, despite its positive effects on agricultural productivity in this case, the contract farming scheme could not achieve the restructuring of the rural labor force toward non-agricultural sectors. Ironically, farmers in the Binh Dao commune tended to increase cultivable land during the agricultural restructuring program, rather than switching their labor forces to non-agricultural sectors. The lack of stable non-farming job opportunities in rural Vietnam results in challenges to the efficiency of agricultural restructuring programs. Consequently, farmers in the Binh Dao commune are still smallholder farmers, depending on the family labor force.

• Journal of Environmental Science International
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• v.23 no.3
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• pp.433-445
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• 2014

The objective of study was to analyze seasonal and inter-annual patterns of water chemistry of Miho Stream watershed during 2004 - 2007 along with some influences of tributaries and summer monsoon on the stream water quality. For the study, eight physico-chemical parameters such as nitrogen, phosphorus, BOD, COD and chlorophyll-a (CHL) etc. were analyzed in relation to spatial and temporal variability of seven sampling sites of the mainstream and some tributaries in the watershed. In the upstream reach, Mean of BOD, COD and TP averaged 3.2 mg/L, 6.5 mg/L and $186{\mu}g/L$, respectively, indicating an eutrophic conditions as a III-rank in the stream water quality criteria from the Ministry of Environment, Korea(MEK). The eutrophic water was due to a combined effect of Chiljang tributary with high nutrients ($TP=844{\mu}g/L$, TN=8.087 mg/L) and the point sources from some wastewater treatment plants. In the meantime, BOD, TN, and TP in the downstream reach were about > 1.2-1.5 folds than the values of the midstream reaches. This was mainly attributed to effluents of nutrient rich-water (mean TN: 11.980 mg/L) from two tributaries of Musim Stream and Suknam Stream, which is directly influenced by nearby wastewater disposal plants. Seasonal analysis of water chemistry showed that summer monsoon rainfall was one of the important factors influencing the water quality, and water quality had a large spatial heterogeneity during the rainfall period. In the premonsoon, BOD in the downstream averaged $6.0{\pm}2.47mg/L$, which was 1.4-fold greater than the mean of upstream reach. Mean of CHL-a as an indicator of primary productivity in the water body, was > 2.2 - 2.9 fold in the downstream than in the upstream, and this was a result of the high phosphorus loading from the watershed. Overall, our data suggest that some nutrient controls in point-source tributary streams are required for efficient water quality management of Miho Stream.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.4
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• pp.327-338
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• 2015

Because of impact on the underwater light field, CDOM can influence the accuracy of global satellite-based measurement of ocean chlorophyll and primary productivity. So we investigated the distribution and seasonal variation of CDOM in the East Sea during summer 2009 and 2011. Among them we report two distinctively different summer cases between 2009 and 2011 year, in which showed the different main sources for CDOM. Regulating factors and sources of CDOM in the East Sea were examined. Comparison between in situ and satellite derived Chl a and CDOM were made to find an influence of CDOM on measurement of satellite derived Chl a. Similar pattern and matching of MODIS Chl a with in situ Chl a 2009 was comparable, but significant discrepancy between MODIS Chl a and in situ Chl a was found, when CDOM was high in summer of 2011. GOCI data showed better matching with in situ data for both Chl a and CDOM, compared to MODIS data in summer of 2011. The presence of high CDOM at the surface layer supplied by vertical mixing seems to affect on the overestimation of Chl a by satellite data.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.7 no.1
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• pp.85-92
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• 1969

The goal for the improvement of rice culture in our country is to increase the rice yield per unit area, and that thoroughly, to equalize the rice yield per unit are highly by adaptation of high technique, while on the side of the efficiency, to increase the productivity of the labour through the cooperative work. And then, the theory for execution of the cooperative rice culture which is the productive system embodying the goal above and the expected effects as well as the future prospect for the development of the cooperative rice culture must be studied and defined. The results studied up to now are summarized as follows: 1. The cooperative rice culture is one of the most effective ways to execute highly efficient farm management and to supply the technical details on the cultivation for equalized high yield per unit area in the rice cultivating districts. 2. For the most effective accomplishment of the cooperative rice culture, the water control, and soil and variety of rice must be investigated in advance an then the basic technical details for the rice culture must be defined. 3. The rice cultivation calender is drawn up with the main technical details of rice culture by the mutual agreement of all farmers belong to the cooperative farm. All technical details for the rice cultivation in the cooperative farm are standardized by the rice cultivation calendar and the main technical operations should be worked together and the other operations executed individually. 4. The technique for rice cultivation, which was difficult to be introduced in the individual farm management, could be introduced easily to the cooperative rice culture, and the rice yield of the cooperative farm was increased 23.3% compared to that of common farm in 1968. 5. At present, the type of the cooperative rice culture is a primary type of the agreement for farm management, rarely including the associated operation type and the contracted operation type for a part of operation, However, for stabilized high yield through the mechanization of the cultivation system, the cooperative farm must be developed for a course promoting the associated operation type including the technique trust type and the contracted operation type according to the condition of location.

• Economic and Environmental Geology
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• v.38 no.6 s.175
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• pp.707-716
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• 2005

Organic geochemical analyses including Rock-Eval pyrolysis, elemental analysis and stable carbon isotope analysis were performed to evaluate the characteristics of organic matter in the ODP Leg 127 Site 794A sediments and to understand paleoceanographic changes. Based on the TOC contents, C/N ratio, HI vs. OI, $\delta^{13}C_{org}$ and C/S ratio, results imply that dark layers containing a large amount of terrigenous organic matter were deposited under the suboxic/anoxic conditions, whereas the light layers containing largely marine organic matter were deposited under the oxic conditions. These results indicate that increasing surface-productivity by the input of a large amount of terrigenous organic matter from adjacent continent led to the deposition of dark layers during the interglacial highstands, whereas marine primary production and dilution caused by Kosa from the China desert area led to the deposition of light layers with the decreased to terrigenous organic matter during the glacial lowstands.

• Journal of The Korean Society of Grassland and Forage Science
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• v.4 no.3
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• pp.187-193
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• 1984

Using the stratifying clip method, we examine the differences in vertical distribution of leaf area and its relationships with dry matter production were investigated in the primary swards of six varieties. The results obtained were as follows: 1. The varieties could be classified into 4 different types according to their of vertical distribution of leaf area within the canopy. Thus, M had a greater leaf area distribution in the base layers and became smaller towards the upper layers, Leto, First and Bundy had the leaf area distribution which was most abundant in the middle layers and became smaller towards the base and the upper layers, Tammisto had a greater leaf area distribution in the middle layers and intensively distributed to the upper layers, and Trader had the relatively uniform leaf area distribution over all layers. 2. Effective leaf area index(ELAI) correlated with leaf area index(LAI), dry weight of plant(DW), stem weight of plant(SW) and stem area index(SAI). 3. The variety with the heading tiller type had the effective leaf area intensively distributed to the upper layers of canopy, but the vegetative type showed a high ratio of effective leaf area index. 4. Varietal differenced was found between the effective leaf area and specific leaf weight(SLW) in each stratum above the layer indicating the highest leaf area density within the canopy. M and Trader had a highly negative significant correlation, but the other varieties was not significant correlation.