• 한국토양비료학회지
• /
• 제48권5호
• /
• pp.456-463
• /
• 2015

The objective of this study was to determine the effects of granular type of silicate fertilizer on watermelon growth, yield, and characteristics of soil in the greenhouse. Four different levels of silicate fertilizer, 0(control), 600, 1,200, $1,800kg\;ha^{-1}$ were applied for experiment. The silicate fertilizer was applied as a basal fertilization before transplanting watermelon. Compost and basal fertilizers were applied based on the standard fertilizer recommendation rate with soil testing. All of the recommended $P_2O_5$ and 50% of N and $K_2O$ were applied as a basal fertilization. The N and $K_2O$ as additional fertilization was split-applied twice by fertigation method. Watermelon (Citrullus lanatus Thunb.) cultivar was 'Sam-Bok-KKuol and main stem was from rootstock (bottle gourd: Lagenaria leucantha Standl.) 'Bul-Ro-Jang-Sang'. The watermelon was transplanted on April, 15. Soil chemical properties, such as soil pH, EC, available phosphate and exchangeable K, Mg, and available $SiO_2$ levels increased compared to the control, while EC was similar and the concentrations of soil organic matter decreased. Physical properties of soils, such as soil bulk density and porosity were not different among treatments. The growth characteristics of watermelon, such as stem diameter, fresh and dry weight of watermelon at harvest were thicker and heavier for silicate treatment than the control, while number of node was shorter than the control. Merchantable watermelon increased by 3-5% compared to the control and sugar content was 0.4 to $0.7^{\circ}Brix$ higher than the control. These results suggest that silicate fertilizer application in the greenhouse can improve some chemical properties of soils and watermelon stem diameter and dry weight, which are contributed to watermelon quality and marketable watermelon production.

• 원예과학기술지
• /
• 제30권3호
• /
• pp.270-277
• /
• 2012

Greenhouse industry has been growing in many countries due to both the advantage of stable year-round crop production and increased demand for fresh vegetables. In greenhouse cultivation, $CO_2$ concentration plays an essential role in the photosynthesis process of crops. Continuous and accurate monitoring of $CO_2$ level in the greenhouse would improve profitability and reduce environmental impact, through optimum control of greenhouse $CO_2$ enrichment and efficient crop production, as compared with the conventional management practices without monitoring and control of $CO_2$ level. In this study, a mathematical model was developed to estimate the $CO_2$ emission from soil as affected by environmental factors in greenhouses. Among various model types evaluated, a linear regression model provided the best coefficient of determination. Selected predictor variables were solar radiation and relative humidity and exponential transformation of both. As a response variable in the model, the difference between $CO_2$ concentrations at the soil surface and 5-cm depth showed are latively strong relationship with the predictor variables. Segmented regression analysis showed that better models were obtained when the entire daily dataset was divided into segments of shorter time ranges, and best models were obtained for segmented data where more variability in solar radiation and humidity were present (i.e., after sun-rise, before sun-set) than other segments. To consider time delay in the response of $CO_2$ concentration, concept of time lag was implemented in the regression analysis. As a result, there was an improvement in the performance of the models as the coefficients of determination were 0.93 and 0.87 with segmented time frames for sun-rise and sun-set periods, respectively. Validation tests of the models to predict $CO_2$ emission from soil showed that the developed empirical model would be applicable to real-time monitoring and diagnosis of significant factors for $CO_2$ enrichment in a soil-based greenhouse.

• 농약과학회지
• /
• 제15권4호
• /
• pp.441-452
• /
• 2011

농경지 중 내분비계장애 추정농약의 잔류 실태를 조사하기 위하여 시설재배 토양을 경기도 가평 등 전국 40개 지역에서 총 40점을 채취하여 현재 우리나라에서 분류한 내분비계장애추정농약 40종 중 등록되어 사용중인 alachlor를 포함한 16종의 농약을 대상으로 GC-ECD 및 HPLC-DAD/FLD를 이용한 다성분동시분석법 및 개별분석법으로 분석하였다. 시험농약의 검출한계는 0.0004-0.005 mg/kg이었으며, 각 시험농약의 회수율 72.69-115.28%의 범위였다. 조사대상 토양 40점 중 16점의 시료에서 cypermethrin 등 4종의 내분비계장애추정농약이 검출되어 37.5%의 검출율을 보였다. 그 중 endosulfna은 12지역에서 검출되어 가장 높은 검출빈도를 보였다. 또한 GUS로 판단할 때 대부분의 검출 농약은 지하수를 오염시킬 가능성이 거의 없었으나 살균제 vinclozolin은 약간의 지하수를 오염시킬 가능성이 있는 것으로 추정되었는데 이는 수용성이 높고 토양 흡착성이 낮은 특성 때문인 것으로 보인다.

• Journal of Microbiology and Biotechnology
• /
• 제22권4호
• /
• pp.563-566
• /
• 2012

To investigate the possibility of horizontal gene transfer between agricultural microorganisms and soil microorganisms in the environment, Bacillus subtilis KB producing iturin and the PGPR recombinant strain Pseudomonas fluorescens MX1 were used as model microorganisms. The soil samples of cucumber or tomato plants cultivated in pots and the greenhouse for a six month period were investigated by PCR, real-time PCR, Southern hybridization, and terminal restriction fragment length polymorphism (T-RFLP) fingerprinting. Our data from Southern blotting and T-RFLP patterns suggest that the model bacteria do not give significant impacts on the other bacteria in the pots and greenhouse during cultivation.

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
• /
• pp.106-107
• /
• 2003

The effect of biological control agent Bacillus sp. (BAC03-3-1, BAC03-3-2, BAC02-4) on pre- and postemergence Sclerotinia rot of perilla (Perilla frutescens var. japonica) caused by Sclerotinia sclerotiorum was determined from greenhouse field trials. The ability of this antagonist to reduce germination of sclerotia of S. sclerotiorum was also evaluated. In the greenhouse, suspension of BAC03-3-1 application as root drench of perilla, which provided as little as 10$\^$7/ cells/ $m\ell$ per gram of soil, significantly increased plant stand in pathogen-infested soil over that in the untreated control. All three isolates reduced the germination of sclerotia of S. sclerotiorum in loamy sand soils in the greenhouse. In loamy sand amended with rice bran the sclerotial germination was inversely correlated (r = -0.79) with perilla stand in the greenhouse. However, a higher rate of bacterial suspension with rice bran(Ig dwt./100g soil) than that applied with bacterial suspensions only was necessary to achieve a comparable reduction in sclerotial germination. In field study, all three isolates added to soil to provide 10$\^$7/ cells/$m\ell$ per gram significantly prevented Sclerotinia rot (73-85％) after 35 days of growth. The isolate BAC02-4, BAC03-3-1 and BAC03-3-2 gave final stands of 65 to 75, 60 to 70, and 55 to 60％, respectively. The addition of rice bran(1 ％) to loamy sand in the field resulted in a 10-fold increase in propagule numbers of the three isolates within 10 days of application.

• 한국토양동물학회지
• /
• 제5권2호
• /
• pp.165-168
• /
• 2000

밭토양에 지렁이가 서식하는지를 알기 위하여 밭토양 이용에 따라 초지, 과수원지, 유기농업 지, 비닐하우스지, 노지에서 지렁이를 조사하였다. 초지와 과수원지는 조사지역 모두에서 지렁이가 서식하였으며, 유기농업지는 8개 조사지역 중에 6개 지역에서만 서식하였고, 비닐하우스지에서는 12개 지역중 5개, 노지는 25개중 5개에서 지렁이 서식이 확인되었으며, 지렁이는 낚시지렁이과 (Lumbricidae)와 지렁이과 (Megascolecidae)에 속하는 지렁이였다. 지렁이 개체수는 과수원지 14마리, 초지가 12마리, 유기농법지가 10마리, 비닐하우스가 7마리, 노지가 3마리 순서로 적었으며 , 생체량은 0.25 m$^2$당 과수원지가 12.3g, 유기농법지가 11.6g, 초지가 10.6g, 비닐하우스지가 4.2 g, 노지가 2.9 g 순서로 적었다. 밭토양의 토양수분이 5% 미만이거나 35% 이상인 경우가 아니면 서식하는 데는 문제가 없었으며, 토양산도는 강산성이나 강알칼리성 토양이 아니면 토양에 적응해 가며 서식하는 것으로 조사되었다. 그리고 유기물은 1%미만 정도로 적으면 지렁이가 서식하지 않고 다른 곳으로 이동하는 것으로 나타났다.

• 한국농공학회지
• /
• 제40권4호
• /
• pp.109-119
• /
• 1998

Recently pipe-framed greenhouses are widely constructed on domestic farm area. These greenhouses are extremely light-weighted structures and so are easily damaged under strong wind due to the lack of uplift resistance of foundation piles. This experiment was carried out by laboratory soil tank to investigate the displacement be haviors of cylindrical pile foundations according to the uplift loads. Tested soils were sampled from two different greenhouse areas. The treatment for each soil type are consisted of 3 different soil moisture conditions, 2 different soil depths, and 3 different soil compaction ratios. Each test was designed to be repeated 2 times and additional tests were carried out when needed. The results are summarized as follows : 1. When the soil moisture content are low and/or pile foundations are buried relatively shallow, ultimate uplift capacity of foundation soil was generated just after begining of uplift displacement. But under the high moisture conditions and/or deeply buried depth, ultimate up-lift capacity of foundation soil was generated before the begining of uplift displacement. 2. For the case of soil S$_1$, the ultimate uplift capacity of piles depending on moisture contents was found to be highest in optimum moisture condition and in the order of air dryed and saturated moisture contents. But for the case of soil S$_2$, the ultimate uplift capacity was found to be highest in optimum moisture condition and in the order of saturated and air dryed moisture contents. 3. Ultimate uplift capacities are varied depending on the pile foundation soil moisture conditions. Under the conditions of optimum soil moisture contents with 60cm soil depth, the ultimate uplift capacity of pile foundation in compaction ratio of 80%, 85%, and 90% for soil 51 are 76kg, 115kg, and 155kg, respectively, and for soil S$_2$are 36kg, 60kg, and 92kg, respectively. But considering that typical greenhouse uplift failure be occurred under saturnted soil moisture content which prevails during high wind storm accompanying heavy rain, pile foundation is required to be designed under the soil condition of saturated moisture content. 4. Approximated safe wind velosities estimated for soil sample S$_1$and S$_2$are 32.92m/s and 26.58m/s respectively under the optimum soil condition of 90% compaction ratio and optimum moisture content. But considering the uplift failure pattern under saturated moisture contents which are typical situations of high wind accompanying heavy rain, the safe wind velosities for soil sample S$_1$and S$_2$are not any higher than 20.33m/s and 22.69m/s respectively.

• 한국농공학회:학술대회논문집
• /
• 한국농공학회 2000년도 학술발표회 발표논문집
• /
• pp.327-332
• /
• 2000

This study was carried out to investigate the water requirement of green peppers which are cultivated in a greenhouse under the different soil water conditions. The meteorological conditions during the experiment period was not predominantly different from the conditions in a normal year. The highest leaf area per plant, plant height, and yield were 6,143$\textrm{cm}^2$/plant, 107cm, and 751g/plant, respectively. And daily variation of water requirements of green peppers ranged from 30 to 1,250g/d/plant which was fluctuated with significant difference. Total water requirements per plant which cultivated under the soil water conditions with different saturation ratios were 23,619g for P100, 43,044 for P80, and 2915g for P60, respectively. There were close correlation between plant height and water requirements. Low correlations were found between greenhouse ambient temperature and water requirement, while significant linear regression was shown between both of humidity and solar radiation and water requirement.

• 농약과학회지
• /
• 제20권3호
• /
• pp.221-227
• /
• 2016

본 연구에서는 들깨 시설재배지 토양 및 작물 중 잔류성유기염소계 농약의 잔류량을 조사하였다. 토양 및 작물 중 잔류성유기염소계 농약 분석을 위한 추출 및 정제는 QuEChERS 방법을 다소 개선한 방법으로 수행되었다. 들깨 시설재배지 토양 및 농산물 중 잔류성유기염소계 농약의 회수율은 각각 76.3-113.4 및 79.4-107.3%, 정량한계는 각각 0.03-0.24와 $0.33-0.50{\mu}g/kg$ 수준이었다. 들깨 시설재배지 토양에서 dieldirn 및 endosulfan sulfate 2 성분만이 각각 1.6-9.2 및 $22.0-87.8{\mu}g/kg$ 수준으로 검출되었으나 들깻잎의 모든 시료에서는 검출되지 않았다. 이러한 결과는 들깨 시설재배지 토양이 농산물 안전성을 위협할 정도로 잔류성유기염소계 농약으로 오염되지 않았음을 나타냈다.

• 생물환경조절학회지
• /
• 제25권3호
• /
• pp.218-223
• /
• 2016

온실의 난방부하 중 지중전열부하는 산정방법이나 적용여부가 제각각이고, 온실의 규모에 따라 각각의 방법에는 큰 차이가 있으므로 보다 정확히 국내에 적용할 수 있는 방법을 정립할 필요가 있다. 본 연구에서는 원예시설의 난방부하 산정방법 정립에 필요한 기초자료를 제공하기 위하여 위치와 규모가 다른 3개의 연동 플라스틱 온실에서 난방기간 동안 지온분포와 토양열류를 실측하였으며, 온실의 지중전열부하 산정방법을 검토하고 난방설계에 필요한 기준자료를 도출하였다. 난방중인 온실의 지온분포를 실측하여 실내기온과 비교한 결과 온실의 중앙 부분에서는 지온이 실내기온 보다 높고, 온실의 끝부분과 모서리 부분에서는 지온이 실내기온 보다 낮은 것으로 나타났다. 그러므로 온실의 중앙 부분에서는 지중열이 공급되고, 온실의 측면 부분에서는 외주부를 통해서 열손실이 발생하며, 온실의 규모에 따라 차이가 있는 것으로 판단된다. 건물의 외주부를 통한 열손실 개념을 도입하고, 온실의 규모를 반영하여 수정한 온실의 지중전열부하 산정방법은 타당성이 있는 것으로 평가된다. 토양열류센서를 이용하여 실측한 지중전열량은 실내외 기온차에 비례하여 직선적으로 증가하는 것을 확인할 수 있었다. 지중전열량 분석 결과로부터 지중전열의 방향이 바뀌는 기준온도차를 도출하였으며, 국내 온실의 난방설계에서 대규모 온실은 $10^{\circ}C$ 내외, 소규모 온실은 $12.5{\sim}15^{\circ}C$를 적용할 것을 제안하였다. 또한 지중열류 실측 결과로부터 온실의 외주부 단위길이당 열손실계수를 도출하였으며, 대규모 온실은 $7.5{\sim}10W{\cdot}m^{-1}{\cdot}K^{-1}$, 소규모 온실은 $2.5{\sim}5.0W{\cdot}m^{-1}{\cdot}K^{-1}$를 설계기준 자료로 제안하였다.