干拓地土壤의 除鹽을 위한 石膏處理效果

具滋雄 全北大學校 1989 論文集 Vol.31 No.-

This study was performed to analyze the effects of gypsum treatments for the desalinization of reclaimed tidelands and to obtain the basic data for determiniing the appropriate amount of gypsum. Desalinization experiments with various gypsum treatments were conducted through two water management practices, namely, the leaching method and the rinsing method, using the samples of silt loam soil and silty clay loam soil sollected in reclaimed tidelands. The results obtained from this study were summarized as follows: 1. In accordance with the USDA classification system of salt affected soils, the sample soils, the sample soils used in this study were saline-sodic soils with the high electrical conductivity and the high exchangeable sodium percentage. 2. The gypsum treatments had great effects on the desalinization of reclaimed tidelands by the leaching method, but had no effect on the desalinization of reclaimed tidelands by the rinsing method. 3. The vlaue of pH showed a tendency to increase during the desalinization of reclaimed tidelands and could be decreased in some degree by gypsum treatments. 4. The remarkable effects of gypsum treatments for the desalinization by leaching could be considered to desalinize readily by proving the permeability of soils and to reduce the leaching time elapsed.

水稻作 耕地의 區劃規模에 따른 農業機械의 作業性能(Ⅱ) : 乾畓直播 栽培 Direct-Seeding in dry Land

유수남,구자웅 全南大學校 農業科學技術硏究所 1997 農業科學技術硏究 Vol.32 No.-

본 연구는 건답직파 수도재배의 경우 농업기계 이용측면에서 포장의 대구획화에 따른 경지정리의 적정 구획규모 결정을 위한 기초자료와 영농의 효율화와 생산성 향상을 위한 영농방법 및 이에 따른 기계화 작업체계 수립의 기초자료를 제공하고자 경지구획(경구)의 규모와 형상에 따른 대형 고성능 농업기계의 포장작업능률, 포장작업효율 등을 분석하였으며, 그 연구결과를 요약하면 다음과 같다. 1. 장변 길이가 길어짐에 따라 이앙작업을 제외한 모든 작업에서 포장작업능률과 포장작업효율은 높아지는 것으로 나타났으며, 이에 따라 ha당 총작업소요시간도 줄어들었다. 2. 단변의 길이 증가에 따른 포장작업능률과 포장작업효율은 구동경운, 정지, 파종작업 등에서는 약간씩 증가하였으며, 수확작업에서는 거의 일정하게 나타난 반면, 제초제 살포와 병충해약제 살포 등 방제작업과 추비살포작업에서는 약간씩 낮아지는 것으로 나타났다. 한편 시비작업(기비살포)에서는 단변의 길이 변화에 따라 크게 변동하였다. ha당 총작업소요시간은 대체적으로 방제작업의 비중이 상대적으로 크기 때문에 단변의 길이 증가에 따라 약간씩 감소하는 것으로 나타났다. 3. 포장작업능률은 거의 모든 작업에서 동일한 구획규모에서는 장단변비의 증가에 따라 대체적으로 증가하였으며, 또한 같은 장단변비에서는 구획규모가 클수록 증가하는 것으로 나타났다. 총작업소요시간은 동일한 구획에서는 장단변비가 커질수록 감소하며, 같은 장단변비에서는 구획규모가 클수록 적어짐을 보였다. 그러나 장단변비가 커질수록 포장작업능률 증가율과 총작업소요시간의 감소율은 떨어지는 것으로 나타났다. 4. 대구획화를 위하여 장변의 길이를 길게하는 것은 단변을 길게하는 것보다 거의 모든 작업에서 효과적으로 포장작업능률과 포장작업효율을 높일수 있는 것으로 나타났다. 현행 농업기계 체계를 고려해 볼 때 장변의 길이는 100∼150 m, 단변의 길이는 60∼80 m로 각각 제한되어 적정 구획규모는 약 0.6∼1.2 ha 정도인 것으로 판단되며, 포장의 배수성 개선, 대형 트랙터에 적합한 부착작업기의 채용,포장주행이 가능한 방제 및 추비살포기계의 개발이 이루어진다면 농업기계능률을 높이기 위하여 1.2∼1.6 ha의 구획규모로 경지를 대구획화하는 것이 바람직 할 것으로 보인다. This study was carried out to evaluate the effect of field size on field capacities of farm machines and their operating times for determining the optimum field size in direct-seeding of rice in dry land. As long side length increases, the field capacities and field efficiencies increased and total operating time per ha of the machines decreased in most works. As short side length increases, the field capacities and field efficiencies increased slightly in rotary tilling, pulverizing, and seeding works, and were almost constant in harvesting work. But those were changed irregularly due to the wide effective working width in fertilizing work, and were decreased slightly owing to the time loss for resting in weedicide and pesticide application works. Total operating time per ha of the machines decreased slightly as the short side length increases. As the ratio of long side length to short side length increases under same field size, the field capacities of the machines increased and total operating time per ha of the machines decreased. But, increasing rates of field capacities and decreasing rate of operating time per ha were reduced gradually. In the case of same ratio, field capacities increased and total operating time per ha decreased as the field size increases. Increase of the long side length is more effective than that of the short side length for improving the field capacities of machines and reducing their operating times. Long side length is limited by the loading capacities of chemical distributers and short side length is limited by the effective working width of machines. And therefore long side and short side can be lengthende up to 100 - 150 m and 60 - 80 m, respectively and optimum field size is in the range of 0.6 - 1.2 ha under the current farm machine system. But, if improvement of drainage, and development of chemical distributer which can run in the field are achieved, field size in the range of 1.2 - 1.6 ha is desirable for improving field capacities of machines.

대구획화 (大區劃化) 경지정리에 있어서 용 (用) 배수관리상 제한요소의 검토

구자웅(Ja Woong Koo),손재권(Jae Gwon Son),최진규(Jin Kyu Choi) 전북대학교 농업과학기술연구소 1995 농업생명과학연구 Vol.26 No.-

관개용수로(灌漑用水路)의 수로손실율(水路損失率) 산정(算定)에 관(關)한 연구(硏究)

구자웅 ( Koo Ja-woong ),이기춘 ( Lee Ki-chun ),김재영 ( Kim Jae-young ),이재영 ( Lee Jae-young ) 한국농공학회 1982 韓國農工學會誌 : 전원과 자원 Vol.24 No.2

This study was carried out in order to estimate water losses in irrigation canals, which may be used to evaluate the water requirement for irrigation projects. The conveyance losses were measured by the inflow-outflow method, the seepage losses were measured by the ponding method, and the operation losses in the course of irrigation were calculated by comparing the two kinds of losses. The results obtained in this experiment were as follows; 1. Conveyance losses per unit area of wetted perimeter by the main irrigation canal, the secondary irrigation canal and the tributary irrigation canal, were 1.399X10^-5m³/sec/m², 5.154X10^-5m³/sec/m², and 2.670X10^-5m³/sec/m² respectively in the Goong-sa area. And they were 1.934X10^-5m³/sec/m², 2.149X10^-5m³/sec/m², and 4.558X10^-5m³/sec/m² respectively in the Seong-dug area. 2. Seepage losses per unit area of wetted perimeter by the secondary irrigation canal and the tributary irrigation canal, were 2.180X10^-6m³/sec/m² and 2.168X10^-6m³/sec/m² in the Goong-sa area, 1.150X10^-6m³/sec/m² and 1.084X 10^-6m³/sec/m² in the Seong-dug area respectively. 3. Operation losses per unit area of wetted perimeter by the secondary irrigation canal and the tributary irrigation canal, were 4.936X10^-5m³/sec/m² and 2.453X10^-5m³/sec/m² in the Goong-sa area, 2.034X10^-5m³/sec/m² and 4.450X10-5m³/sec/m² in the Seong-dug area respectively. 4. Conveyance, seepage and operation losses in the Goong-sa area were 6.7%, 94.6%, and 14.0% more than those in the Seong-dug area. Operation losses amount to about 17 times as much as seepage losses in the Goong-sa area and about 29 times in the Seong-dug area. 5. The seepage losses depend much on the soil texture, ranging from 7.437X10^-7m³/sec/m² to 2.430X10^-6m³/sec/m². 6. Water loss rates in the main irrigatin canal, the secondary irrigation canal and the tributary irrigation canal, were estimated as 8.49%, 37.27% and 9.81% respectively in the Goong-sa area. And they were estimated as 15.10%, 32.67% and 13.78% respectively in the Seong-dug area.

우리나라 서남해안 간척지 및 간석지 토양의 화학적 특성 (I) - 중금속 오염물질의 형태별 함량 분포 -

구자웅 ( Koo Ja Woong ),손재권 ( Son Jae Gwon ),조재영 ( Cho Jae Young ) 한국농공학회 2006 한국농공학회논문집 Vol.48 No.1

The chemical fractions of heavy metals were investigated in the soils of reclaimed and natural tidelands of southwest coastal area of Korea. The distribution pattern of each heavy metal in different fractions was in the order: 1) Cu : organic bound > organic complex > residual > exchangeable = water soluble. 2) Cr : residual > organic bound > organic complex > water soluble > exchangeable. 3) Pb : organic bound > residual > organic complex > water soluble > exchangeable. 4) Cd : residual > organic bound > organic complex > water soluble = exchangeable. 5) Zn : organic bound > residual > organic complex > water soluble > exchangeable. The content of residual Zn showed positive correlation with organic matter content but organic bound Zn showed negative correlation with CEC. The content of residual and exchangeable Cd showed highly positive correlation with organic matter content but residual, organic bound, and exchangeable Cd showed negative correlations with CEC. Water soluble Pb showed positive correlation with CEC but organic bound Pb showed negative correlation with CEC.

간척지 토양의 제염예측 프로그램 개발

구자웅 ( Ja Woong Koo ),손재권 ( Jae Gwon Son ),최진규 ( Jin Kyu Choi ),이동욱 ( Dong Wook Lee ),송재도 ( Jae Do Song ) 한국농촌계획학회 2002 농촌계획 Vol.8 No.3

The PTDRT model as prediction techniques for desalinization in reclaimed tidelands was developed and verified whether it is applicable to reclaimed tidelands at the beginning stage. The changes of salt concentration during desalinization, the water requirements and period required for desalinization, were simulated according to soil properties and desalinization methods by regression analyses. The program was also designed to systematize input data and analysis data associated with desalinization. and to confirm the results by a graphic form. All input data and the results can be printed after the form of a typical report.

증발계(蒸發計) 증발량(蒸發量)의 시계렬(時系列) 및 통계적(統計的) 특성(特性) 분석(分析)

구자웅 ( Ja Woong Koo ) 한국농공학회 1977 韓國農工學會誌 : 전원과 자원 Vol.19 No.3

In order to estimate furture consumtive use, some statistical characteristics of 22-year pan evaporation data at four selected stations were calculated in this study. Districal distribution, trend analysis and time-series, statistical and periodic analysis for annual, monethly and ten-day values were performed in the statistical analysis. The stations are Seoul, Taeku, Jeonju and Mokpo for monthly data, and Suweon data are compared to the reported Penman values. The results are as followed: 1. Annual evaporation ranged to 990-1,375mm varying with the locations of the stations. The Districal distribution of evaporation in the Republic is shown in Fig. 1. 2. The trend analysis for annual evaporation resulted in detail in Table 2 and Fig. 2, through simple moving average methods. The results show relatively short-period data of about 10 years would be acceptable for field use. 3. The means and dispersions of monthly evaporation at four stations are detailed in Table 3. 4. The monthly evaporation approached to the trend of normal distribution Fig. 3 showed the examples of normal distribution for each typical monthly data. 5. The correlograms detailed in Fig. 4, shows the time-series characteristics of monthly evaporation, whose periodic term should be twelve months. 6. The periodic analysis for monthly evapolation results in Table 4. Fig. 5 shows the comparison of estimated values to actual and the trend approaches Shuster's periodic trend. 7. A periodic description of days after March 1 for irrigation periods was developed to predict ten-day evaporation in Fig. 6. The ten-day evaporation is different in the distribution form and occurence period of maximum values from the reported Penman's man's evapotranspiration.

석고처리에 의한 간척지토양의 제염효과 분석

구자웅 ( Koo Ja Woong ),최진규 ( Choi Jin Kyu ),손재권 ( Son Jae Gwon ),이기성 ( Lee Ki Sung ) 한국농공학회 1999 한국농공학회 학술대회초록집 Vol.1999 No.-

Ibis study was performed to analyze desalinization effects on gypsum treatments m reclaimed tidelands and to obtain the basic data for developing prediction techniques of desalinization to be applicable in the beginning of tideland reclamation. In this study, the reclamation experiments with 4 treatments were conducted through the leaching method, using the samples of silt soil and silt loam soil collected in 5 units of tideland reclamation projects. The electrical conductivity, exchangeable sodium percentage and hydraulic conductivity were analyzed in order to investigate the effects of desalinization for reclaiming the tidelands with high salt concentration.

간척지 토양의 제염예측 프로그램 개발

구자웅 ( Koo Ja Woong ),최진규 ( Choi Jin Kyu ),손재권 ( Son Jae Gwon ),이동욱 ( Lee Dong Wook ) 한국농공학회 2001 한국농공학회 학술대회초록집 Vol.2001 No.-

The PTDRT model as prediction techniques of desalinization in reclaimed tidelands was developed and verified in order to be applicable to reclaimed tidelands at the beginning stage. In this model, the changes of salt concentration during desalinization, the water requirements and period required for desalinization, were simulated according to soil properties and desalinization methods by regression analyses. This program was also designed to systematize input data and analysis data associated with desalinization, and to confirm the results by a graphic form. All input data and the results are able to be printed after the form of a typical report.

우리나라 서남해안 간척지 및 간석지 토양의 화학적 특성 (II) - 인의 형태별 함량 분포 -

구자웅 ( Koo Ja Woong ),손재권 ( Son Jae Gwon ),조재영 ( Cho Jae Young ) 한국농공학회 2006 한국농공학회논문집 Vol.48 No.2

The chemical fractions of phosphorus were investigated in the soils of reclaimed and natural tidelands of southwest coastal area of Korea. The content of total-P varied to ranged from 322 to 614 mg/kg dry weight with a mean value of 467 mg/kg. The order of different fractions of phosphorus in reclaimed tideland soils was as follows: 1) inorganic phosphorus: Ca-P > Fe-P > Al-P > reductant soluble Fe-P. 2) organic phosphorus: Inositol-P > nucleic acid-P > phospholipid-P. The content of Al-P showed negative correlation with organic matter content but showed positive correlation with pH. The content of Fe-P showed negative correlation with clay mineral content but showed positive correlation with organic matter content. Reductant soluble Fe-P and Ca-P were no correlation with soil properties. The content of inositol-P showed highly positive correlation with clay mineral, organic matter content, and CEC.