• 한국농공학회지
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• 제12권2호
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• pp.1960-1964
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• 1970

본시험사업기간(本試驗事業期間)이 $9{\sim}2$월초(月初) 사이기 때문에 시험포장(試驗圃場)을 임대(賃貸)하여 흡수관리설공사(吸水管理設工事)가 끝나자 이어 장려품질(品質)인 맥류(麥類) 2종(種) (밀 : 농림 4호 쌀보리 : 도원)을 파종하고 발아상태(發芽狀態)와 초기생육(初期生育)만 조사(調査)하고 나머지는 내년(來年) $1{\sim}6$월(月) 사이에 조사(調査)를 완료(完了)하고 이어 벼의 시험(試驗)을 하기로 한다.

• 산업경영시스템학회지
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• 제32권4호
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• pp.223-227
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• 2009

The study presents two measurement split-plot models with a restricted randomization to save cost and time. Split-plot models are used to handle HTCM (Hard To Control Measurement) factors such as high temperature and long-time catalyst control. The models developed are represented by the processes for estimating the measurement precisions, that is, gauge R&R. The study also introduces three-step procedures to indentify resolution, improve R&R reduction, and evaluate the precision effect.

• The Korean Journal of Ecology
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• 제19권4호
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• pp.341-351
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• 1996

In order to elucidate the differences in early successional development among similary aged old-fields having different soil nitrogen (N), caused by the land use history before at abandonment, the response of plant community along an experimental nitrogen gradient (control plot (No), plot NI with 5.8g $N/m^2$, plot N2 with 11.7g $N/m^2$ and plot N3 with 23.3g $N/m^2$) was investigated in a five-year-old abandoned field. Although the N content in soil among treatments was similar at the end of the growing season, N concentrations in plant tissue increased with the amount of N supplied. These results suggest that almost all the N contained in N-enriched soil might be absorbed by plants during the growing season after N supply. Vegetation tended to grow vigorously by nitrogen supply, and the standing biomass increased significantly in plots NI and N2 . Species richness of plants, especially of annuals and perennials, was more reduced than the control plot, and the species diversity was also reduced by N supply. The importance value (IV) of species by N supply differed in each species along the position on the successional sere: Artemisia princeps var. orientalis as the dominant species in this old-field decreased slightly; annuals as the earlier successional species decreased clearly along nitrogen gardients; Erigeron annuals as the earlier successional species and as a strong competitor with Artemisia princeps var. orientalis had the highest IV by small N supply; Miscanthus sinensis and Rubus crataegifolius as the later successional species increased by large N supply. These results suggest that old-fields with high soil N might show the structural and functional characteristics of the earlier successional stages, but community composition in those old-fields might be changed more quickly from the sarlier successional species than the later successional species.

• 한국환경복원기술학회지
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• 제14권2호
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• pp.107-115
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• 2011

The purpose of the study is to analyze the environmental characteristics of fish acute toxicity that is dependent on the harmfulness of ACQ (Alkaline Copper Quat)-Treated Wood and Oryzias latipes mortality in a comprehensive way, provide objective verification method on the eco-toxicity and environment-friendliness of landscaping materials and methods, and utilize it as a basic datum for evaluation criteria. The main results are summarized as follows : 1. As a result of analysis on the harmfulness characteristics, each experimental plot showed different values respectively. In particular, it has been found that in proportion to the volume of testing materials, COD and Cu increases at a constant rate, compared to the input water. In the plot C with three testing materials, COD increased 67 times more than that of the input water, and Cu increased up to 12.36mg/L. 2. In case of fish toxicity, plot C, B, A all showed a mortality rate of 100%, indicating that fish toxicity is strong. In particular, the mortality rate of each plot within the initial time of one and a half hour showed clearly, which suggests that the fish toxicity is influenced by the increased concentration of hazardous substances depending on the volume ratio of testing materials. 3. As a result of comparison and analysis on the harmfulness and fish toxicity, the harmfulness showed different values on each experimental plot but, we found that the changing rate of values of toxicity of COD and Cu is mutually similar to that of mortality in the initial hour according to the experiment of fish toxicity, which shows that COD and Cu are major factors to increase fish toxicity.

• 한국물환경학회지
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• 제28권3호
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• pp.436-443
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• 2012

This research was focused on the effect of rice straw and rice straw mat on the reduction of upland field non-point source (NPS) pollution discharges. Six experimental plots of $5{\times}22m$ in size and 3% in slope prepared on gravelly sandy loam soil were treated with control, rice straw cover and rice straw mat cover. Radish in Spring growing seasons were cultivated. NPS pollution discharge was monitored and compared with respect to the treatments. The surface cover rate of rice straw and rice straw mat right after the treatments was 64.7% and 73.7%, respectively. Rainfall of the 16 monitored events ranged from 12.8 mm to 538.2 mm. Runoff coefficient of the events was 0.01~0.67 in control plot, 0~0.63 in rice straw plot and 0~0.45 in rice straw mat plot. The reduction of runoff compared to the control plot was 5.4~99.7% in rice straw plot and 32.9~100% in rice straw mat plot. The reduction of NPS pollution load was 52.0% for SS, 28.5% for T-N and 35.2% for T-P in rice straw plot and 79.8% for SS, 68.3% for T-N and 53.3% for T-P in rice straw mat plot. This research revealed that rice straw mat cover on the soil surface could not only increase the crop yield and farmer's income but also reduce the NPS pollution loads significantly.

• 기술사
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• 제1권1호
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• pp.18-25
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• 1968

Higher yield in rice paddies is greatly dependent on adequately balanced and timely supply of water. A majority of rice paddy in Korea is generally irrigated by rainfall, but in many cases it has to be supplemented by artificial irrigation for optimum rice culture. Although the water requirement of rice plant is for higher Than that of athec crops, submerged condition of rice paddy is not Necessarily required. The moisture requirement of rice plant varies with its growing stages, and it is possible to increase the irrigation efficiency through reduction of water loss due to percolation in rice paddies. An experimental plots were set up by means of sandomized block design with three duplication; (a) All time submerged, (b) Economically controlled, and (c) Extremely controlled. Three different irrigation periods Were (a) Initial sage, (b) Inter-stage, and (c) Yast stage. The topsoil of the three plots were excavated to the depth of 30 cm and then compacted with clay of 6 cm thickness. There after, they were piled up with the excavated top soils, leveled and cored with clay of 6 cm thickness around footpath in order to prevent leakage. The results obtained from the experiments are as follows, 1. There is no difference among the three experiments plots in terms of physical and chemical conditions, soil properties, and other characteristics. 2. Culm length and ear length are not affected by different irrigation methods. 3. There is no difference in the mature rate and 1, 000 grain weight of rice for the three plots. 4. The control plot which was irrigated every three days shows an increased yield over the all the time submerged plot by 17.8 percent. 5. The clay lined plot whose water holding capacity was held 5 days long, needs only to be irrigated every 7 days. 6. The clay lined plot shows an increased yield over the untreated plot ; over all-the-time submerged plot by 18 percent ; extremely controlled plot by 18 percent, and economically controlled plot by 33 percent. 7. It may be saved in water requirement about one Thirds.

• 한국농공학회논문집
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• 제55권4호
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• pp.21-28
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• 2013

The objective of the study was to investigate the effect of rice straw mat, rice straw mat with PAM (Polyacrylamide) and gypsum addition on surface runoff and sediment discharge in field. Six experimental plots of $5{\times}22m$ in size and 3 % in slope prepared on gravelly sandy loam soil were treated with control, rice straw mat cover with gypsum and rice straw mat cover with gypsum and PAM. Radish in Spring and Chinese cabbage in autumn growing seasons were cultivated. Non point source (NPS) pollution discharge was monitored and compared among the treatments. Rainfall of the 10 monitored events ranged from 17.0 mm to 93.5 mm. Runoff coefficient of the events was 0.005~0.239 in control plot, 0~0.176 in rice straw plot with gypsum and 0~0.046 in rice straw mat plot with gypsum and PAM. When compared to the control plot, the runoff amount was reduced by 10.4~100 % (Ave. 60.8) in rice straw plot with gypsum and 80.7~100 % (Ave. 96.7 %) in rice straw mat plot with gypsum and PAM. The reduction of NPS pollution load was 54.6 % for BOD5, 71.5 % for SS, 41.6 % for TN and 61.4 % for T-P in rice straw with gypsum plot and 91.9 % for BOD5, 92.0 % for SS, 88.0 % for TN and 88.5 % for T-P in rice straw mat with gypsum and PAM plot. This research revealed that rice straw mat cover with soil amendments on the soil surface could not only increase the crop yield but also reduce the NPS pollution loads substantially.

• The Korean Journal of Ecology
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• 제9권1호
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• pp.91-101
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• 1986

To investigate the distribution of Plantago asiatica Linne, almost, restricted on the road-side, the plant growth analyzed by experimental cultivation under the condition of tread-pressure; 10 times/day (7.33kg/$cm^2$ ), 20 times/day (12.27kg/$cm^2$), 30 times/day (20.05kg/$cm^2$ ) and the control plot (1.68kg/$cm^2$ ). The matter production in the 10-time-per-diem plot (7.33kg/$cm^2$ ) of tread-pressure howed more large value than that inthe control one (1.68kg/$cm^2$ ) and those in the 20-0time-per-diem plot (12.27kg/$cm^2$ ) and the 30-time-per-diem one (20.05kg/$cm^2$ ) small values than that of the control plot. Especially, the growth of roots and spikes was extremely repressed. The number of leaves, scapes and lateral buds tend to increase in the tread-pressure of 20 times/day (12.27kg/$cm^2$ ) and 30 times/day (20.05kg/$cm^2$ ). The water contents of roots along the increase of tread-pressure to continuosly decreased. By the increase of tread-pressure, T/R ratio and C/F ratio their group decreased. The plant growth (7.33kg/$cm^2$ ) in the 10-time-per-diem plot increased more than that in the control one is regarded as the effect of tread-pressure affection on the road-side distribution of this plant.

• 한국토양비료학회지
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• 제42권Spc호
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• pp.45-46
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• 2009

간척지 토양은 도시화와 산업화로 인해 잠식되는 농경지를 대체하는 식량공급원으로 간척지는 쌀 산업 외에 원예, 축산 등 다양한 생물산업 기반으로 활용되고 있다. 그리고 간척지 논농업(간척지 논 307만 ha)은 온실가스 저감 기능을 가지고 있으며 년간 논 1ha당 이산화탄소 흡수량 21.9t, 산소 공급량 15.9t으로 알려져 있다. 그러나 높은 염농도와 지하수위, 지하수 상승에 의한 재염화 현상, 토양 물리화학성과 배수 불량, 논의 경우 적정 유효토심은 50cm 정도이나 간척지 논 유효토심 20cm 이하로 유효토심이 매우 낮은 편이다. 또한 간척년대 경과할수록 제염은 되나 토양물리성 불량, 시비량 과다와 양분 불균형 발생으로 인하여 수분과 양분보유능 향상 토양관리 기술 개발 필요하다.

• 한국환경농학회지
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• 제22권1호
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• pp.26-35
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• 2003

농어촌 등에서 소규모로 발생하는 하수를 환경친화적이고 높은 하수처리효율을 유지하면서 하수처리장의 장기간 사용을 위한 최적의 여재를 선정하기 위하여 자연정화공법을 이용한 소형하수처리장치를 호기성조 및 혐기성조로 구분하여 시공한 다음, 하수처리량 및 여재 입경별 수처리 효율을 조사하였고, 호기성조와 혐기성조에서 여재 입경별 하수의 투수속도를 조사한 결과는 다음과 같다. 호기성조 처리수 및 방류수중의 pH 및 EC는 여재입경에 따라서 별 차이가 없었고, 용존산소는 호기성조를 통과한 호기성조 처리수의 용존산소는 큰 폭으로 증가하였으나 혐기성조를 통과한 방류수의 용존산소는 호기성조 처리수에 비해 약간 감소하여 여재입경 및 하수처리량에 따라서 별 차이가 없이 약 $2.4{\sim}5.1\;mg/L$정도이었다. BOD, COD 및 탁도 처리율은 여재 대($4{\sim}10\;mm$)를 사용했을 경우에도 호기성조 처리 수에서 BOD 처리율은 약 91%이상 COD 처리율은 73%이상, 탁도 처리율은 83%이상이었으며, 이들 처리율은 여재입경이 작을수록 증가하였고, 모든 조건에서 방류수중의 BOD 처리율은 98%이상, COD 처리율은 91%이상, 탁도 처리율은 98%이상이었다. 여재입경별 총 질소 및 총 인 처리율은 여재입경이 작을수록 약간 증가하였고, 모든 조건에서 방류수중의 총 질소 처리율은 약 $45{\sim}59%$, 총 인 처리율은 약 $80{\sim}96%$ 정도이었다. 하수 처리율 및 투수속도를 고려해 볼 때 하수처리장 호기성조의 최적입경은 $2{\sim}4\;mm$정도, 혐기성조의 최적입경은 $0.1{\sim}4\;mm$정도가 적절한 것으로 사료되었다. 따라서 이러한 조건을 자연정화공법을 이용한 하수처리장에 적용하면 높은 하수처리효율을 유지하면서 하수처리장의 공극폐쇄현상이 일어나지 않아 장기간 운전할 수 있을 것으로 판단된다.