• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.315-321
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• 2010

Greenhouse soil cultivated with excessive compost and chemical fertilizer has been an issue to deteriorate soil and water quality in the environment. The objective of this study was to evaluate the nutrient outflow by desalting method, flooding soil surface, after vegetable cropping in greenhouse soils. Field experiment from July to September 2008, was conducted to quantify greenhouse locations, i.e. alluvial plain and local valley. The changes of desalinization in both locations were higher as the amounts of irrigated and drained water were increased. Particularly, the ratio of desalinization in alluvial plain was much higher (66.7%) than the one in local valley (45.6%). However, $NH_4$-N contents of local valley soil during the flooding were higher than in those of alluvial plain. This was caused by high total nitrogen and organic matter in local valley soil than those in alluvial plain soil. With comparing to the input and output loads of T-N and T-P in greenhouses with local valley and alluvial plain soils, the output loads of nutrients were larger than the input loads of nutrients. This result showed that the flooding soil surface can be a good treatment to desalinize greenhouse soils. However, this conclusion remained that the flooding water containing high N and P concentrations might cause the secondary effect on the quality of streams and groundwater since excessive nutrient concentrations can be the main cause of eutrophication problem in aquatic environment.

• Journal of Bio-Environment Control
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• v.20 no.1
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• pp.8-13
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• 2011

This research was carried out to investigate relationship between underground part environment control and growth or yield of sweet pepper in greenhouse as affected by covering materials. Daily amount of applied nutrient solution for research period in the greenhouse of plasticfilm house was more 1.6 times than that in glass house. But daily absorptance rate of nutrient solution and specific electrical conductance of rockwool between two greenhouses were not different in the range of 71.3-73.3% and $4.17{\sim}4.23dS{\cdot}m^{-1}$ respectively. Leaf area of sweet pepper, in leaf growth characteristics in two greenhouses, were $123.0cm^2$/leaf (in glass house) and $119.5cm^2$/leaf (in plasticfilm house), but the another (fresh and dry weight, dry matter) were not different. But weekly yield per square meter in glass house was more 1.3 times than that in plasticfilm house as $850g{\cdot}m^{-2}$ and $650g{\cdot}m^{-2}$, respectively. Effect of slab EC and absorptance rate of nutrient solution on leaf growth characteristics and yield between two greenhouses were not different. The results show when sweet pepper is cultured in greenhouse as affected by covering materials and above ground part environment, the plant growth and yield are little affected by underground part environment.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.491-495
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• 2014

Mites were collected from organic cultivations of greenhouse cucumbers and identified as Tyrophagus neiswanderi (Acari: caridae). T. neiswanderi (length, $490.1{\mu}m;$ width, $288.1{\mu}m$) is a very small, milky-white, and egg-shaped mite, and it mainly causes damage to the leaves, flowers, and fruits of cucumber plants. In the early growing season of cucumbers, the shoots of seedlings became pale and yellow because of T. neiswanderi, and eventually shrinkage or bud-failing was observed in the plants. In the middle of the growing season, T. neiswanderi caused white spots on the leaves and flowers of the plants, and the spots gradually became holes. T. neiswanderi also caused severe damage to young fruits by feeding on the rinds of the fruits, inducing malformations and lowering the economic value.

• Journal of Bio-Environment Control
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• v.18 no.1
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• pp.23-28
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• 2009

This study was conducted to evaluate the effect of optimized environment conditions with growth stage in photoautotrophic micropropagation on the growth of potato (Solanum tuberosum L. cv. Dejima) plantlets and energy efficiency. Optimum environment conditions at each stage were decided in our previous study. For the evaluation of optimized environment control, potato plantlets were cultured under four different conditions: photoautotrophic optimum conditions of photosynthetic photon flux density (PPFD) and $CO_2$ levels with growth stage (POG), photoautotrophic constant condition with average PPFD and $CO_2$ levels (PCA), photoauototrophic constant condition with maximum PPFD and $CO_2$ levels (PCM), and photomixotrophic conventional condition with 3% sucrose (PMC) as control. As a result, environment control with growth stage (POG) significantly promoted all the growth characteristics such as the number of nodes and unfolded leaves, shoot height, shoot diameter, and fresh and dry weights of potato grown in vitro. In addition, based on dry weight consumed electricity and $CO_2$ were the lowest in POG suggesting the highest energy efficiency among the treatments. After transferring potato plantlets to greenhouse, the plantlets under POG showed vigorous growth, which was pretty similar with those under PMC. The accumulations of dry matter in POG were 4.7 times in vitro and 3.8 times in greenhouse as much as those in the conventional control (PCM). Thus, we concluded that in vitro environment control with growth stage induced vigorous growth of potato plantlets both in vitro and in greenhouse with less energy consumption.

• Journal of Environmental Impact Assessment
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• v.18 no.2
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• pp.69-78
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• 2009

In order to provide fundamental data for developing greenhouse gas emission factor, we investigated power plants in Korea using B-C oil as Energy source. The power plant is a major source of greenhouse gases among the sectors of fossil fuel combustion, thus information of its emission factors is very essential to the establishment of control strategies for the greenhouse gas emissions. The caloric value of fuel was analyzed using calorimeter and the calorific value was 10,419 kcal/kg. The $CO_2$ concentration of flue gas and elemental analysis were conducted using GC-FID and elemental analyzer. The $CO_2$ emission factors from fuel analysis was 75,410 kg/TJ and that from $CO_2$ gas analysis was 94,265 kg/TJ. When compared with IPCC values, the emission factors by the fuel analysis was 2.5% lower, and that by $CO_2$ gas analysis was about 21.85% higher.

• Journal of Advanced Navigation Technology
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• v.16 no.1
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• pp.89-95
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• 2012

This paper introduces domestic and international trends and researches related with U-Greenhouse systems. USN (Ubiquitous Sensor Networks), along with the development of networks as well as science and technology, is a new computing paradigm which is the convergence of user-oriented physical activity space and virtual space of electronics and computing and also provides services according to change in surrounding environment at anytime and anywhere. The U-Greenhouse system is to apply USN to agricultural production, logistics and distribution management which are relatively insufficient to utilize IT technology. Thus, applying u-IT technology to agriculture can reinforces international competitiveness of the agricultural sector through the effects such as cost cutting as a rise in output, logistics and distribution management.

• Journal of Biosystems Engineering
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• v.32 no.4
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• pp.247-255
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• 2007

During the winter season in Korea, the relative humidity of greenhouse at night often exceeds 90% because air temperature inside the greenhouse is usually controlled using a heater with all of windows closed to minimize heat loss, thereby requiring the use of a dehumidifier that can maintain optimum humidity levels of $70{\sim}80%$ to provide a good growth condition of crops. Also, such a high humid condition can cause the development of a pest, such as insects, fungi or diseases. However, the use of most conventional dehumidifiers for low temperature dehumidification is limited because their performance is degraded due to frost accumulation on the evaporator coil. This study was carried out to develop a refrigeratory-based dehumidifier suitable for low temperature dehumidification in greenhouse cultivation. The developed dehumidifier consists of a condenser and an evaporator installed separately so that relative and absolute humidity levels can be reduced when air passed through the condenser and evaporator, respectively. The prototype dehumidifier showed a dehumidification capacity of $5{\sim}7kg/h$ when air with a temperature of $15{\sim}25^{\circ}C$ and a relative humidity of $70{\sim}95%$ came into the dehumidifier. Under the condition that either temperature or relative humidity was fixed, the amount of condensed water was proportional to the levels of both temperature and relative humidity.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.4
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• pp.315-323
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• 2018

Fossil fuel combustion during fishing activities is a major contributor to climate changes in the fishing industry. The Tier1 methodology calculation and on-site continuous measurements of the greenhouse gas were carried out through the use of fuel by the coastal and offshore gillnet (blue crabs and yellow croaker) and trap (small octopus and red snow crab) fishing boats in Korea. The emission comparison results showed that the field measurements are similar to or slightly higher than the Tier1 estimates for coastal gillnet and trap. In offshore gillnet and trap fisheries, Tier1 estimate of greenhouse gases was about $1,644-13,875kg\;CO_2/L$, which was more than the field measurement value. The $CO_2$ emissions factor based on the fuel usage was $2.49-3.2kg\;CO_2/L$ for coastal fisheries and $1.46-2.24kg\;CO_2/L$ for offshore fisheries. Furthermore, GHG emissions per unit catch and the ratio of field measurement and Tier1 emission estimate were investigated. Since the total catch of coastal fish was relatively small, the emission per unit catch in coastal fisheries was four to eight times larger. The results of this study could be used to determine the baseline data for responding to changes in fisheries environment and reducing greenhouse gas emission.

• Journal of Climate Change Research
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• v.6 no.3
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• pp.175-184
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• 2015

In this study GC and PAS were used to calculate $N_2O$ concentration of exhaust gas from Wood Chip combustion system. Fuel supplied to the incinerator was collected and analyzed and then the analysis result was used to calculate $N_2O$ emissions. Tier 3 and Tier 4 Method were used to calculate the $N_2O$ emissions. Plant's Specific emission factor of $N_2O$ by Tier 3 Method was 0.35 kg/TJ, while default emission factor of Wood?Wood Waste proposed by 2006 IPCC G/L was 4 kg/TJ. So the $N_2O$ emission factor of this study was 3.65 kg/TJ lower compared to the IPCC G/L. The total emissions calculated by Plant's specific emission factor was 4.22 kg during the measuring period, but by Tier 4 Method it was 7.88 kg. This difference in emissions was caused by the difference of continuous measuring and intermittent sampling. It would be necessary to apply continuous measuring to calculate emissions of $Non-CO_2$ gas whose the density distribution is relatively high. However currently, according to the target management guideline of greenhouse gas and energy, the continuous measuring method to calculate greenhouse gas emission is applied only to $CO_2$. Therefore for reliable greenhouse gas emission calculation it would be necessary to apply continuous measuring to calculate $Non-CO_2$ gas emission.

• Journal of Bio-Environment Control
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• v.7 no.1
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• pp.15-24
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• 1998

The greenhouse temperature controls in general have been managed by the above-ground part environment, But the temperature of root zone was known very important factor for the 9rofth and the yield of vegetables in greenhouse. The purpose of this study is to develop a good method for cultivation using solar energy which can apply warming soil and to develop the greenhouse soil temperature automatic control system. Followings are summary of this study：1 When the greenhouse inner temperature changes were about 24$^{\circ}C$ during a day in October, the temperature of non-warmed soil was differenced 6$^{\circ}C$ in the depth 10cm and 3$^{\circ}C$ in the depth 20cm. 2. When water supply temperature was kept at 40, 50 and 6$0^{\circ}C$, the lowest soil temperature in the depth of 10cm is 2$0^{\circ}C$ and that of 20cm was 23$^{\circ}C$. and when the water supply temperature was over 4$0^{\circ}C$, the space heating temperature did not affect the temperature variation of soil. 3. In comparison with conditions of the warmed and non-warmed soil, when the water supply temperature is 28$^{\circ}C$, soil temperatures had the high temperature of 4$0^{\circ}C$~7$^{\circ}C$ in the depth of 10cm to 20 cm. 4. The line of boundary area was appeared in the depth of 15~20cm, 13~19cm and 12~17cm. when the water supply temperature was 4$0^{\circ}C$, 5$0^{\circ}C$ and 6$0^{\circ}C$. 5. When th inner greenhouse air temperature is maintained over 11$^{\circ}C$ and the water supply temperature is supported 28$^{\circ}C$, the lowest temperature is kept up over 2$0^{\circ}C$.