• Proceedings of the Korean Society of Crop Science Conference
• /
• 1998.10a
• /
• pp.41-67
• /
• 1998

This study aimed at examining the investment and economic analysis of greenhouse horticultural project area by governmental subsidy project. There were only 5 project areas that economic efficiency of investment is recognized in 30 project area in Kyungsangnam-do. And there are 7 project areas to gain farm firm revenue. These were possible area to develop to farm firm. There are 4 project areas to gain farm firm revenue in 18 project areas of glass greenhouse area, and 8 project areas to gain farm firm revenue in 12 project areas-vinyl greenhouse area. The rate of return of the fixed capital is higher in the vinyl greenhouse area than in the glass greenhouse area by type of greenhouse. There were cultivated tomatoes, cucumbers, peppers, etc. in the greenhouse area. The investment efficiency of the fixed capital is higher in cucumber and pepper than in other vegetables. Flowers a re lower than the vegetable in investment efficiency.

• Journal of Biosystems Engineering
• /
• v.16 no.4
• /
• pp.399-407
• /
• 1991

In Korea, the cultivation area under the plastic greenhouse was 1,746 ha in 1975, and 36,656 ha in 1989, it shows that the greenhouse cultivation area was increased by 21 times during last 14 years. The greenhouse cultivation area of 90~93% has been kept warm with double layers of plastic film and thermal curtain knitted with rice straw, and the rest area of 7~10% has been heated by fossil fuel energy. The use of rice straw thermal curtain is inconvenient to put it on and off, on the other hand the use of fossil fuel heating system results in the increase of production cost. To solve these problems, at first the heating load and the storable solar energy in greenhouse during the winter season were predicted to design solar utilization system, secondly a solar thermal storage system filled with latent heat storage materials was developed in this study. And then finally the thermal performance of greenhouse-solar energy storage system was analyzed theoretically and experimentally.

• Korean Journal of Agricultural Science
• /
• v.40 no.4
• /
• pp.317-323
• /
• 2013

This research was conducted to obtain the basic information for establishment of standard guidelines in the design and installation of roof ventilation system in single-span plastic greenhouse. To achieve this, the greenhouse structure & characteristics, cultivation status, and ventilation system were investigated for single-span greenhouse with roof ventilation system cultivating the Cucurbitaceae vegetables, watermelon, cucumber, and oriental melon. Most of single-span watermelon greenhouse in Haman and Buyeo area were a hoop-style and the ventilation system in those greenhouses mostly consisted of two different types of 'roof vent (circular or chimney type) + side vent (hole) + fan' and 'roof vent (circular type) + side vent (hole or roll-up type)'. The diameter of circular and chimney-type vent was mostly 60cm and the average number of vents was 10.5 per a bay with vent spacing of average 6.75m. The ratio of roof vent area to floor area and side vent area in the single-span watermelon greenhouse with ventilation fan were 0.46% and 7.6%, respectively. The single-span cucumber greenhouse in Haman and Changnyeong area were a gable roof type, such as even span, half span, three quarter and the 70.6% of total investigated single-span greenhouses was equipped with a roof ventilation fan while 58.8% had a circulation fan inside the greenhouse. The ratios of roof vent area to floor area in the single-span cucumber greenhouse ranged from 0.61 to 0.96% and in the case of the square roof vent, were higher than that of the circular type vent. On average, the roof ventilation fan in single-span cucumber greenhouse was equipped with the power input of 210W and maximum air volume of $85.0m^3/min$, and the number of fans was 9.75 per a bay. The number of roof vent of single-span oriental melon greenhouse with only roll-up type side vent ranged from 8 to 21 (average 14.8), which was higher than that of other Cucurbitaceae vegetables while the vent number of the greenhouse with a roof ventilation fan was average 7 per a bay.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.14 no.3
• /
• pp.15-20
• /
• 2018

To study the effects of solar energy in a greenhouse, outdoor air temperature and wind speed on inside air temperature, a simulation model for forecasting the greenhouse air temperature was conducted on the basis of the energy and mass balance theory. Application of solar energy to the greenhouse is major area in the renewable energy research and development in order to save energy. Recently, considering the safety and efficiency of the heating of greenhouse, clean energy such as geothermal and solar energy has received much attention. The analysed greenhouse has $50m^2$ of ground area which located in jocheon-ri of Jeju Province. Experiments were carried out to collect data to validate the model. The results showed that the simulated air temperature inside a plastic greenhouse agreed well with the measured data.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.64 no.6
• /
• pp.13-23
• /
• 2022

The purpose of this study was to analyze the impact of greenhouse cultivation area and groundwater level changes due to the water curtain cultivation in the greenhouse complexes, which are mainly situated along rivers where water resources are easy to secure. The groundwater observation network in Miryang, Gyeongsangnam-do, located downstream of the Nakdong River, was selected for the study area. We classified the groundwater monitoring well into the greenhouse (riverside) and field cultivation areas (plain and mountain) to compare the groundwater impact of water curtain cultivation in the greenhouse complex. The characteristics of groundwater level changes classified by terrain type were analyzed using the observed data. Riverside wells have significant permeability coefficients and are close to rivers, so they are greatly affected by river flow and precipitation changes so that water level shows a specific pattern of annual changes. Most plain wells do not show a constant annual change, but observation wells near small rivers and small-scale greenhouse cultivation areas sometimes show annual and daily changes in which the water level drops during winter. Compared to other observation wells, mountain wells do not show significant yearly changes in water level and show general characteristics of bedrock aquifer well with a low permeability coefficient.

• Journal of Environmental Science International
• /
• v.7 no.4
• /
• pp.531-540
• /
• 1998

To examine water pollution status of agricultural water source of greenhouse area in Gyeongnam, the ground water quality was investigated six times at five areas in Gyeongnam from October in 1995 to March in 1996. pH of ground water were generally in the range of 5.9∼7.6. But a site in Changnyeong area was out of the range In 6.0∼8.5 which is water quality standard for agriculture. COD of ground water was below 2.8mg/l. NH4+-N contents in ground water was very low in all areas and the average of NO3'-N contents in Changnyeong and Chinju area was high with 13.2 and 11.5mg/l respectively. Hardness, SO42- and EC of ground water In Hmm were higher than any other area. Fe and Mn contents of ground water in Kimhae were higher than any other area with 7.17 and 0.95wt, respectively. Heavy metals such as Cu, Cd, Pb and Zn of ground waker were below water Quality standard far agriculture but some sites were over. Between COD and SS in ground water were not correlated with rInG.338,'but between COD and NH4+, -N were positively correlated. And EC was positively correlated with Ca2+, Mg2+ and SO42-. Ground water pollution status of agricultural water source of greenhouse area in Gyeongnam was genrrally high in order of Sacheon < Chinju < Hmn < Kimhae < Changnyeong.

• Journal of Biosystems Engineering
• /
• v.19 no.3
• /
• pp.211-221
• /
• 1994

In this study, to maximize the solar energy utilization for greenhouse heating during the winter season, solar energy-underground latent heat storage system was constructed, and the thermal performance of the system has been analyzed to obtain the basic data for realization of greenhouse solar heating system. The results are summarized as follows. 1. $Na_2SO_4{\cdot}10H_20$ was selected as a latent heat storage material, its physical properties were stabilized and the phase change temperature was controlled at $13{\sim}15^{\circ}C$. 2. Solar radiation of winter season was the lowest value in December, and Jinju area was the highest and the lowest value was shown in Jeju area. 3. The minimum inner air temperature of greenhouse with latent heat storage system(LHSS) was $7.0{\sim}7.5^{\circ}C$ higher than that of greenhouse without LHSS and was $7.0{\sim}11.2^{\circ}C$ higher than the minimum ambient air temperature. 4. Greenhouse heating effect of latent heat storage system was getting higher according to the increase of solar radiation and was not concerned with the variation of minimum ambient air temperature. 5. The relative humidity of greenhouse with latent heat storage system was varied from 50 to 85%, but that of greenhouse without LHSS was varied from 30 to 93%. 6. The heating cost of greenhouse with solar energy-latent heat storage system was about 24% of that with the kerosene heating system.

• Journal of Biosystems Engineering
• /
• v.24 no.1
• /
• pp.19-24
• /
• 1999

Motivated by the need for developing the more efficient lighting system for light culture of strawberries in the greenhouse, this paper aims at acquiring and suggesting more concrete and scientific foundation of illuminating position, numbers of light source by investigating the types of lighting system and illumination distribution in the greenhouse for light culture of strawberries. The results of investigation and experiment are summarized as following below: 1. The types of lighting system used in the greenhouse producing strawberries were classified as 1 line and 2 lines lighting system. 2. As for the arranging types of artificial light, 2 lines lighting system, were classified as Z-type, N-type and W-type. (Refer Fig. 3) 3. The results of illumination distribution for Z-type, N-type and W-type of 2 lines illuminating system in the greenhouse with a small size tunnel measured at the height of 1.5m from the ground with 220V, 100W lamp in 6m light gap showed that maximum illuminance are 961x, 1211x, 1251x, minimum illuminance are 4.41x, 4.71x, average illuminance are 33.71x, 43.11x, 44.51x and standard deviations are 28.31x, 35.41x, 38.31x at each types. 4. Proportion of the area below optimal illuminance to floor area at the two lines illuminating system of Z-, N-, and W-type in greenhouse were appeared as 39.4%, 26.0% and 26.3%, respectively. Also proportion of the area over optimal illuminance to floor area at the two lines illuminating system of Z-, N-, W-type in greenhouse were appeared as 16.8%, 14% and 14.7%, respectively. Thus N-type was superior to the others from the view points of optimal illumination distribution and energy saving.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2005.10a
• /
• pp.604-609
• /
• 2005

Runoff characteristics of organic matters and nutrients from greenhouse site in paddy field area were investigated during the irrigation period in 2004. The greenhouse selected which situated near the Nam river, Jinju, Korea used the ground water as the irrigation purpose. And, the rotating system of paddy field to upland was adapted as a cropping system which is a typical practice in this area. Various items such as total phosphorus(T-P), total nitrogen(T-N), dissolved oxygen(DO), BOD, etc. were observed to figure out the seasonal and spatial variation in the study sites. it was found that the risk of water pollution due to the contamination of nutrients in canals in green house sites, and their neighbouring small sized streams are much higher than those in ordinary paddy field areas. Further surveys and investigations are required to find out the counter measures to reduce water pollution occurred in greenhouse sites.

• Journal of Korean Society of Rural Planning
• /
• v.4 no.2
• /
• pp.96-102
• /
• 1998

A field survey with interview was conducted to get information on the irrigation water usage for greenhouse farming. Three study regions were selected which represent geographical characteristics such as ,neighboring urban area, flat-field area, and mountainous area. Several items were investigated and analysed such as location of greenhouse, type of irrigation water resources, type of irrigation method used, way to decide intake facility size, farmers'satisfaction on intake facilities performance and water quality, and needs for water quality test. It was found that greenhouse farmers did not take an advantage of technical assistances. Proper criteria or guidelines for selection and operation of water intake facilities were not available.