• Korean Journal of Soil Science and Fertilizer
• /
• v.23 no.2
• /
• pp.87-93
• /
• 1990

A statistical model to predict soil temperature from the ambient meteorological factors including mean, maximum and minimum air temperatures, precipitation, wind speed and snow depth combined with Fourier time series expansion was developed with the data measured at the Suwon Meteorolical Service from 1979 to 1988. The stepwise elimination technique was used for statistical analysis. For the yearly oscillation model for soil temperature with 8 terms of Fourier expansion, the mean square error was decreased with soil depth showing 2.30 for the surface temperature, and 1.34-0.42 for 5 to 500-cm soil temperatures. The $r^2$ ranged from 0.913 to 0.988. The number of lag days of air temperature by remainder analysis was 0 day for the soil surface temperature, -1 day for 5 to 30-cm soil temperature, and -2 days for 50-cm soil temperature. The number of lag days for precipitaion, snow depth and wind speed was -1 day for the 0 to 10-cm soil temperatures, and -2 to -3 days for the 30 to 50-cm soil teperatures. For the statistical soil temperature prediction model combined with the yearly oscillation terms and meteorological factors as remainder terms considering the lag days obtained above, the mean square error was 1.64 for the soil surfac temperature, and ranged 1.34-0.42 for 5 to 500cm soil temperatures. The model test with 1978 data independent to model development resulted in good agreement with $r^2$ ranged 0.976 to 0.996. The magnitudes of coeffcicients implied that the soil depth where daily meteorological variables night affect soil temperature was 30 to 50 cm. In the models, solar radiation was not included as a independent variable ; however, in a seperated analysis on relationship between the difference(${\Delta}Tmxs$) of the maximum soil temperature and the maximum air temperature and solar radiation(Rs ; $J\;m^{-2}$) under a corn canopy showed linear relationship as $${\Delta}Tmxs=0.902+1.924{\times}10^{-3}$$ Rs for leaf area index lower than 2 $${\Delta}Tmxs=0.274+8.881{\times}10^{-4}$$ Rs for leaf area index higher than 2.

• Journal of Bio-Environment Control
• /
• v.7 no.4
• /
• pp.311-323
• /
• 1998

This study was conducted to analyze the temperature characteristics under tunnel type greenhouse to cultivate watermelon in Sungju region. Air temperature of tunnel type greenhouse was descending rapidly after sunset, and the time required the air temperature inside greenhouse nearly reached the outside air temperature was about 2.5 hours. The maximum air temperature in tunnel type greenhouse, in case of high air temperature day, was exceeding 4$0^{\circ}C$ during day time. Air temperature inside greenhouse during night time could sustain about 2~3$^{\circ}C$ higher than the outside air temperature. But it was necessary to supply supplemental heat when the air temperature was below optimum growth temperature. Soil temperature in the depth of 20cm under soil surface could maintain higher than 2$0^{\circ}C$ and the variation range in a day was 3~5$^{\circ}C$, and the soil temperature descending due to irrigation was about 5~6$^{\circ}C$.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.148-148
• /
• 2022

콩[(Glycine max(L.)]은 우리나라에서 벼와 더불어 주요한 식량작물이다. 농촌진흥청에서는 콩 생육데이터를 수집하여 생산성 향상모델을 개발하기 위해 '농업빅데이터수집및생산성향상모델개발' 사업을 수행하고 있다. 수집되는 콩 데이터는 농가정보, 콩 생육정보, 토양정보 부분으로 구성되어 있으며 농가정보는 시군, 시군구, 품종, 파종량, 종자확보경로 등이 수집되고 있다. 그리고 콩 생육정보는 경장, 줄기굵기, 마디수, 가지수, 꼬투리수, 꼬투리립수, 개체당 입수, 종실수량 등이 수집되어 있다. 토양정보는 수분, 지온, EC 등이 수집되고 있다. 주요 항목의 평균은 경장 47.4 cm, 줄기굵기 11.1 mm 마디수 12.7 개, 꼬투리수 54.0 개, 꼬투리립수 2.7 개, 종실수량 227.9 kg/10a 정도이며 토양수분은 26.3 %, 지온은 27.1 ℃ EC는 2.58 ds/CM 정도이다. 주요 형질의 상관관계는 종실수량과 개체당 협수가 0.651로 나타났으며 가지수, 꼬투리수, 개체당협수와 줄기굵기는 각각 0.783, 0.653, 0.663 정도로 나타났다. 추후 이를 기반으로 다중회귀 등 분석 가능한 방법(머신러닝 등)을 적용하여 콩수량을 예측할 수 있는지 검토할 필요가 있다. 또한 본 사업으로 수집된 자료를 분석하여 콩 수량에 영향을 미치는 주요 요인을 평가한 결과는 콩 생산성 향상을 위한 모델 작성에 중요한 자료로 활용될 수 있을 것으로 예상된다.

• Proceedings of the Korean Society for Bio-Environment Control Conference
• /
• 2001.04b
• /
• pp.27-28
• /
• 2001

온실의 차광설계에 필요한 기초자료를 제시하기 위하여 온실모형과 실험온실을 이용하여 외부차광재의 적정 설치간격 분석, 차광재별 광투과율 분석, 차광율에 따른 온실내부온도의 변화 분석, 차광이 온실내부의 지온변화에 미치는 영향분석 및 외부차광과 내부차광의 차광효과 비교를 실시하였다. 외부경사차광시 온실 지붕과 차광재의 설치간격은 10-30cm에서 차광효율이 가장 좋은 것으로 나타났으나 환기창의 개폐를 위한 공간이 필요하지 않는 온실에서는 10cm 정도이면 충분한 간격이 될 것으로 판단된. (중략)

• Journal of Bio-Environment Control
• /
• v.10 no.2
• /
• pp.80-87
• /
• 2001

This study was conducted to provide basic data for the design of shading facility of greenhouse. The proper distance between external shading screen and roof surface, transmissivity of shading materials, and shading effects of external and internal shadings were analyzed. About a distance of 10 cm between inclined external shading screen and roof surface was enough to guarantee the external shading effect in the greenhouse without roof vent. The inside temperature of greenhouse installed with 85% internal shading screen was lower the maximum of 4$^{\circ}C$ and mean of 2$^{\circ}C$ than that with 55% internal shading screen in both natural ventilation and no ventilation condition. The difference of soil temperature between shading and no shading greenhouse was great, but the difference by shading rate or shading method was small. The performance of external shading for controlling inside temperature down was superior to that of the internal shading. The externally inclined shading screen parallel to the roof surface of greenhouse was more effective than the externally horizontal shading screen in controlling inside temperature of greenhouse without roof vent.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.4
• /
• pp.511-514
• /
• 2012

Polyethylene mulches have been used for weed control in vegetable production in Korea. One of the additional benefits associated with polyethylene mulches is soil warming. The objective of this study was to evaluate the effects of colored mulches on soil temperature change and Chinese cabbage yield. Mulch treatments were green (GV), black (BV), transparent (TV), and non-mulched (NM) soil. The highest soil-warming effect occurred under green mulch, and the lowest effect was found under black mulch. Daily mean values of soil temperature (10 cm depth) under GV were $2^{\circ}C$ higher than in NM soil. At midday (16:00), mean soil temperature was higher by $3.9^{\circ}C$ in GV, $3.1^{\circ}C$ in BV, and $2.1^{\circ}C$ in TV as compared to NM soil. At night (20:00-06:00), there was no significant difference in soil temperature among the treatments of different colored mulch, but soils in the mulch treatments were $2.4^{\circ}C$ higher as compared to NM soil. As compared with NM, the yield of Chinese cabbage under GV, BV, and TV were higher by 6.0, 26.0, and 12.0%, respectively.

• Journal of Bio-Environment Control
• /
• v.10 no.1
• /
• pp.15-22
• /
• 2001

A soil temperature was known as extremely important factor in terms of measuring the values of the growth and yield of vegetable in the greenhouse. A low temperature water irrigation was had much trouble in its growth. This study was performed to analyze the effect of the heating water irrigation on the soil temperature and the growth of a cucumber within a greenhouse environment. Soil temperature was 5-7$^{\circ}C$ below to 10cm in depth and 2-3$^{\circ}C$ to 20cm when the irrigation water temperature was 13$^{\circ}C$ (non-warme water irrigation). Soil temperature was similar to irrigation water temperature at 5cm in depth and was 1.5-2$^{\circ}C$ below at 10cm when the irrigation water temperatures were 2$0^{\circ}C$, $25^{\circ}C$. The early growth rates of heating water irrigation were 109-110% in plant height, 107-108% in leaf number, 103% in node number compared with those of unheated water irrigation for 30 days after planting it. The rates of total yield were 115% in 2$0^{\circ}C$ water irrigation plots and 121% in $25^{\circ}C$ water irrigation plots while those of unheated water irrigation plots were.

• 대한생식의학회:학술대회논문집
• /
• 2003.12a
• /
• pp.120-121
• /
• 2003

• Proceedings of the Korean Society for Bio-Environment Control Conference
• /
• 1999.11a
• /
• pp.213-216
• /
• 1999

우리나라의 기후 특성상 여름철에는 온실내 기온과 지온이 과다하게 상승하여 정상적인 작물 생육을 기대하기 어렵다. 이러한 고온현상을 극복하기 위해 우리나라 시설원예 농가에서는 소극적이면서 비용이 적게 드는 흑색 차광망이나 자연환기를 주로 이용하고 있으며 냉방 효과가 적어 문제가 되고 있다. 근래 온실 냉방에 대한 중요성을 인식하고 증발냉각시스템을 도입하는 시설원예농가가 증가하고 있으나 기술적인 측면에서 아직 많은 문제점들이 남아있는 실정이다. (중략)

• Journal of Bio-Environment Control
• /
• v.25 no.3
• /
• pp.218-223
• /
• 2016

The calculation method of ground heat exchange in greenhouses has different ideas in each design standard, so there is a big difference in each method according to the size of greenhouses, it is necessary to establish a more accurate method that can be applied to the domestic. In order to provide basic data for the formulation of the calculation method of greenhouse heating load, we measured the soil temperature distribution and the soil heat flux in three plastic greenhouses of different size and location during the heating period. And then the calculation methods of ground heat exchange in greenhouses were reviewed. The soil temperature distributions measured in the heating greenhouse were compared with the indoor air temperature, the results showed that soil temperatures were higher than room temperature in the central part of greenhouse, and soil temperatures were lower than room temperature in the side edge of greenhouse. Therefore, it is determined that the ground heat gain in the central part of greenhouse and the perimeter heat loss in the side edge of greenhouse are occurred, there is a difference depending on the size of greenhouse. Introducing the concept of heat loss through the perimeter of building and modified to reflect the size of greenhouse, the calculation method of ground heat exchange in greenhouses is considered appropriate. It was confirmed that the floor heat loss measured by using soil heat flux sensors increased linearly in proportion to the temperature difference between indoor and outdoor. We derived the reference temperature difference which change the direction of ground heat flow and the perimeter heat loss factor from the measured heat flux results. In the heating design of domestic greenhouses, reference temperature differences are proposed to apply $12.5{\sim}15^{\circ}C$ in small greenhouses and around $10^{\circ}C$ in large greenhouses. Perimeter heat loss factors are proposed to apply $2.5{\sim}5.0W{\cdot}m^{-1}{\cdot}K^{-1}$ in small greenhouses and $7.5{\sim}10W{\cdot}m^{-1}{\cdot}K^{-1}$ in large greenhouses as design standard data.