To find out the responses of soybean genotypes in terms of different levels of irrigation with the aim of evaluating the growth, yield, and its optimum levels of irrigation, an experiment was conducted at the Field of Crop Botany Department, Bangladesh Agricultural University, Mymensingh during the period from November 2000 to February 2001. Five levels of irrigation viz. ~textrmI0 : no irrigation, ~textrmI1 : one time irrigation at 20 days after sowing (DAS), ~textrmI2 :two times irrigation at 20 and 40 DAS, ~textrmI3 : three times irrigation at 20, 40, and 60 DAS, and ~textrmI4 : four times irrigation at 20, 40, 60, and 80 DAS and three genotypes of soybean viz. BS-3, BS-16, and BS-60 were used in this experiment. The crop was grown in a split plot design having three replications. The plant height, leaf area index, crop growth rate, shoot dry weight, branches ~textrmplantI-1 , filled pods ~textrmplantI-1 , seeds ~textrmplantI-1 , seed yield, and harvest index were influenced significantly by irrigation and these were found to be highest at three times irrigation except branches ~textrmplantI-1 . The chlorophyll content increased but empty pods ~textrmplantI-1 decreased with increase in irrigation levels. Genotypes of soybean varied significantly in terms of growth attributes at various growth stages except shoot dry weight at 90 DAS. The genotype BS-3 performed better compared to other genotypes and gave maximum seed yield.

농업용수 회귀율을 조사하기 위하여 2003년 관개기 동안 많은 실측을 수행하였다. 본 연구지역은 경상남도 창녕군에 위치한 대암양수장 유역일원이다. 관개용수를 공급하기위하여 건설된 대암 양수장 유역 내 논에 대하여 물수지분석을 실시하였다. 본 연구지역에서의 일 강우량 자료를 수집하였으며, 또한 관개율, 배수율, 침투 및 증발산을 실측하였다. 관개량과 배수량은 기록형수위계(GTDL-L10)를 설치하여 관계기 동안 지속적으로 관측하였다 침투 및 증발산은 직경

This study was conducted to seek the effective water management method of the irrigation reservoirs. Joongpyong reservoir was selected for the hydrologic monitoring, and investigated from May in 1999 to December in 2001. The water level and amount of outlet discharge were measured, the stage discharge equation as a rating curve was induced, and which were compared to the irrigation water requirements calculated by a daily simulation model. The water balance of Joongpyong reservoir was analyzed, mainly on the reservoir storage ratio during irrigation period. Comparing the observed storage and simulation data, the results of the simulation were well agreed with the measured data.

Soybeans [Glycine max (L.) Merr.] are frequently exposed to unfavorable environments during growing seasons and water is the most important factor limiting for the production system. The purpose of this study was to determine the leaf water potential changes by irrigation, and to evaluate the relationships of leaf water potential, growth and yield in soybeans. Three soybean cultivars, Hwangkeumkong, Shinpaldalkong 2, and Pungsannamulkong, were planted in growth chamber and field with irrigated treatments. Leaf water potential of three soybean cultivars was positively correlated with leaf water content during vegetative and reproductive growth stages in growth chamber and field experiments. Leaf water potentials measured for three soybean cultivars under growth chamber were higher than those of under field conditions. Higher leaf water potential with irrigated plots under field was observed compared to conventional plots during reproductive growth stages. Leaf water potentials of three soybean cultivars were continually decreased during reproductive growth stages under field and there was no significant difference among them. Number of leaves, leaf water content, pod dry weight, number of seeds and seed dry weight with irrigated plots were higher than those of conventional plots. The results of this study suggested that leaf water potential could be used as an important growth indicator during the growing season of soybean plants.

In this paper, the study area is selected Sungju Reservoir which was constructed with an agricultural purpose and determined the optimal water management plan among the five cases of classified irrigation area by using Linear Programming. As a results of reservoir operation, the additional water quantity of classified irrigation area showed 16.036×106m3/year, 19.404×106m3/year, 18.864×1006m3/year, 4.032×106m3/year and 0.672×106m3/year and the total water supply quantity showed 69.628×106m3/year, 70.048×106m3/year, 67.979×106m3/year, 67.979×106m3/year, and 69.939×106m3/year respectively. Therefore, the case-Ⅱ was adopted with water management plan of optimum. It is also known that the maximum irrigation area augmentation effect appears in the case which will use the additional water quantity in field irrigation of the case-Ⅱ which was adopted.

In 1980s, studies on the river environment and the management techniques to maintain the quality of water achieved actively. From the beginning of 1990s, the concept considering the river ecology and conservation in urban area have been introduced in Korea. Recently, some environment friendly projects on the rivers have been executed and some are under way. Many small rivers in rural areas have been maintained considering landscape and partly ecology. However until the pilot project named Songsam drainage channel project started in 1998, there were no studies and projects on the irrigation and drainage channels considering environment friendly maintenance. Korea Agricultural and Rural Infrastructure Corporation (KARICO) is going to introduce environment friendly and naturally favorable maintenance technique when the new projects to reform the irrigation and drainage channels are planned. Irrigation channel in O-dong project site in Yeomsan-myeon, Younggwang-gun was designed considering environment friendly consolidation and maintenance.

In order to plan the effective irrigation project in unripened reclaimed paddy fields, the estimation of criteria of irrigation water requirements for the normal growth of crops is very important. This study was carried out to determine the leaching requirements before cultivating crops, the consumptive use of water by the growth of crops, and preventive water requirements of resalinization during the growth period in unripened reclaimed paddy fields. The irrigation water requirements in good permeable soils were estimated as 2,530mm for culvert treatment(S1CW3) and 3,080mm for non-culvert treatment(S1NW4), which were 1.8 times and 2.4 times as high as the irrigation water requirements in common rice fields, respectively. And, in case of poor permeable soils, 3,360mm for culvert treatment(S2CW4) and 3.580mm for non-culvert treatment(S2NW4) were estimated, which were 2.5 times and 2.8 times higher than the normal irrigation water requirements, respectively.

Growth and yield of licorice were investigated under the different conditions of ridge height, planting density, and irrigation in order to establish its cultural practices for the domestic production with the aim to substitute the import. Seedlings were grown under low ridge(20cm) and high ridge(40cm) in low density plot(60×30cm) and high density plot(40×30cm), respectively. The low ridge cultivation of large seedlings increased plant height and root length under low density, and stem and root diameter under high density compared to the high ridge cultivation. In the high ridge cultivation, high density plot was 1.1 to 1.3 times in plant height, root length, stem and root diameter as high as low density one. Fresh and dry weight of plant and root in high ridge were 1.3 to 1.5 times as high as those in low one. The growth of small seedlings(4~10g) were generally poor compared to that of large seedlings. High density plot in low ridge showed the good growth characteristics including plant height, root length, stem and root diameter, and number of branch. High density plot was 1.4 to 1.6 times in fresh and dry weight of plant and root as high as low density plot. In the seasonal changes of growth under various irrigation regimes, the twice irrigation a day produced the more number of leaf than the other regimes since around 46 days after transplanting. The former irrigation resulted in 1.2 to 1.4 times in plant height as long as the other irrigations around 26 days after transplanting and then the difference was increased to 1.6 to 2.0 times around 64 days after transplanting. Under the twice irrigation a day, plant height, root length, stem diameter, root diameter, number of leaf, fresh plant weight, dry plant weight, fresh root weight, dry root weight were 1.6 to 2.0, 1.1, 1.2 to 1.6, 1.3 to 1.8, 1.9 to 2.7, 1.7 to 8.0, 1.6 to 2.8,2.0 to 3.0, 1.6 to 2.7 times as high as those under the other irrigation regimes, respectively.

In this lysimeter experiment, temporal changes of water percolation rate, irrigation requirement and No3 －-N leaching were investigated under different cultural practices that were no-till direct seeding on flooded paddy (NTDSF), till direct seeding on flooded paddy (TDSF), and transplanting. The highest water percolation rate of 3,001 l/m2 was measured in NTDSF. Others were 2,551 l/m2 and 2,210 l/m2 in TDSF and transplanting. Water percolation rate in NTDSF and TDSF was increased by 36% and 15% compared to transplanting. Water percolation rates in all cultural practices were increased remarkably from the reproductive growth stage and relatively large amount of water loss through percolation was measured even after the reproductive growth stage. A total irrigation requirement was 3,469 l/m2 in NTDSF and 2,898 l/m2 in TDSF. That was equivalent to 45% and 21 % of increase compared to 2,389 l/m2 in transplanting. The largest No3 －-N leaching through the entire rice growing period was 701 mg/m2 in NTDSF and was followed by 494 mg/m2 in TDSF and 465 mg/m2 in transplanting. The ratios to the total amount of No3 －-N leaching at the vegetative growth stage, reproductive growth stage and ripening stage were 31 %, 41 % and 28% in NTDSF; 21 %, 48% and 31 % in TDSF; and 18%, 48% and 35 % in transplanting.

작약 생육기간중 관수가 생육과 수량에 미치는 영향을 구명하고자 시험을 수행한 결과는 다음과 같다. 1 지상부 생육은 생육초기(5월1일∼6월12일)관수한 처리구가 경장 79.4cm, 경의 굵기 6.5cm로서 자연 강우나 대조구에 비해 각각 13.6∼7.4cm, 0.5mm씩 더 크거나 굵었다. 2. 지하부 생육은 생육 초기 관수가 근장 34.0cm, 근수 43.6개/주로서 자연 강우보다 각각 6cm, 5.5개/주 크거나 많았으며, 수량도 2,349kg/10a로서 자연 강우나 대조구에 비해 각각 13,8% 증수되었다. 3. 상품수량은 생육초기 관수가 2,045kg/10a로서 자연 강우의 1,708kg/10a, 대조구의 1,776kg/10a에 비해 각각 20, 15% 향상되었다.

Irrigation pipeline networks consist mainly of buried pipes and are therefore relatively free from topographic constraints. Installation of irrigation pipeline systems is increasing since the systems have several advantages compared to open channel systems. To achieve economic design of pipeline networks, the layout should meet several conditions such as shortest path, maximum flow, and least cost. Graph theory is mathematical tool which enable to find out optimum layout for complicated network systems. In this study, applicability of graph theory to figure out optimum layout of irrigation pipeline networks was evaluated.

This study was carried out to obtain the basic information for breeding cold-tolerant rice varieties with high yield-productivity through wide crosses between indica and japonica rice. Genetic analysis was conducted using 55 F1 s obtained from half-diallel crosses among eleven cultivars of various origin including indica and japonica rice. Screening for cold tolerance was done with cold-water irrigation after transplanting until ripening stage. Both general combining ability (GCA) and specific combining ability (SCA) effects were highly significant in all characters associated with dry matter accumulation at 30 and 50days after cold-water irrigation (DAC). The variance of GCA was much larger than that of SCA in plant height, shoot dry weight per plant (DWP), crop growth rate (CGR) and cold-water response index (CRI) of these characters except CRI of shoot dry weight per plant. The DWP, CGR and CRI of these characters of Gaochan 102, Tong88-7 and TR22183 were markedly higher than those of the others. GCA effects of these varieties on DWP, CGR and their CRI were also higher than those of the others, indicating that they are useful as promising parents for breeding cold-tolerant varieties. Analysis of genetic parameters for 11~times 11 half-diallel F1 s revealed that inter-locus gene interaction were concerned in the expression of plant height at 50 DAC, CRI of DWP at 50 DAC, and CRI of CGR, and that intra-locus gene interaction for plant height and the other characters were partial dominance and over-dominance, respectively. Narrow-sense heritability (h2 N ) was the highest in plant height as 0.729, and the lowest in CRI of DWP at 30 DAC as 0.048, suggesting that selection for cold tolerance will be quite effective in case that the selection criterion is the performance itself.f.

Extensive research has been conducted on effects of drought stress on growth and development of soybean but information is rather restricted on the limited-irrigation system by way of precaution against a long-term drought condition in the future. The experiment for limited-irrigation was conducted in transparent vinyl shelter at Asian Vegetable Research and Development Center (AVRDC), Taiwan in 1997. Two soybean varieties, Hwangkeum and AGS292, improved in Korea and AVRDC, respectively were used for this experiment. The relationships between normalized transpiration rate (NTR) and fraction of transpirable soil water (FTSW) in both varieties were similar that the NTR was unchanged until FTSW dropped to about 0.5 or 0.6. At FTSW less than those values, NTR declined rapidly. Days required to harvest in both varieties were significantly prolonged at IR6 treatment compared to any other treatments. Daily mean transpiration rate was significantly higher at IR5 treatment, as averaged over varieties. Similarly, water use efficiency was also high at 1R5 treatment. In both varieties, seed yield was the greatest at the IR5 treatment, as compared to any other limited-irrigation treatments, due to the increased seed number and high transpirational water use efficiency. The indices of input water and seed yield for the different limited-irrigation treatments against control indicated that Hwangkeum produced 59.6% or 60.7% of seed yield using 36.1% or 44.9% of input water, as compared to control, by irrigation at only R5 or R6 stages, respectively. The AGS292 produced 56.1% of seed yield with 35.4% of input water of control, when irrigated at R5 stage. The results of this study have elucidated that the limited irrigation at R5 stage in soybean can be minimized yield loss with such small quantity of water under the environment of long-term drought stress and the expected shortage of agricultural water in the future.

The experiment was conducted to clarify irrigation requirement and percolation rate in rice paddy. The four rice cultural system of no-tin, till, transplanting, and direct seeding condition were treated in the lysimeter filled with sandy loam soil. The amounts of irrigation and soil percolation were measured daily, and irrigation requirement was estimated. The daily percolation was 19.5 l/~textrmm2 in no-till direct seeding on flooded paddy surface, 17.4 l/~textrmm2 in both of till-direct seeding on flooded surface and no-till transplanting, and 15.2 l/~textrmm2 in transplanting plot. This is equivalent to 19.5, 17.4, and 15.2 mm per day, respectively. Highest irrigation requirement was 3,770 l/~textrmm2 in no-till direct seeding plots. Others were 3,249, 2,577, and 2,321 l/~textrmm2 in till-direct seeding, no-till transplanting and transplanting plot, respectively. The estimated irrigation requirement of no-till transplanting, till-direct seeding and no-till direct seeding was increased by 11, 37, and 59% compared to till-transplanting plot. Percolation rate of no-till transplanting, till direct seeding and no-till direct seeding was increased by 12%, 40%, and 66%, respectively compared to the till-transplanting plot. The percolation rate in paddy soil was increased greatly after reproductive stage of rice.

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.

파종기(播種期)와 생육초기(生育初期) 관수(灌水)가 삼도시호(三島柴胡)의 수량(收量)에 미치는 영향(影響)을 구명(究明)코자 1995년부터 1996년까지 시험(試驗)을 수행(遂行)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 봄파종 시호(柴胡)의 출현일수(出現日數)는 파종후(播種後) 10일 간격으로 20mm씩 3회 관수한 시험구에서 38일로 무관수구(無灌水區)의 54일에 비하여 16일 단축(短縮)되었다. 2. 입모율(立毛率)은 10일간격 20mm씩 3회 관수한 시험구에서 64%인데 비하여 자연강우시 46%, 무관수에서는 25%로 아주 저조하였다. 3. 파종기(播種期)에 관수(灌水)한 경우 지상부(地上部) 및 지하부(地下部)의 생육(生育)이 무관수(無灌水) 및 자연강우(自然降雨)에서 보다 양호(良好) 하였으며 10a당 수량(收量)은 10일 간격 20mm 3회 관수한 경우 58kg으로 자연강우, 무관수에 비하여 각각 20%, 94%의 증수효과(增收效果)가 있었다. 4. 생육초기(生育初期)(5~6월) 10일 간격으로 30mm씩 6회에 걸쳐 관수한 것이 가장 효과적(效果的)이었다.

마 재배시 장기간의 한발(旱魃)에 대비하여 물의 효육적인 관수(灌水)를 위한 적정 관수(灌水)시기 구명시험을 수행하였던 바 얻어진 결과를 요약하면 다음과 같다. 1. 토성별 토양수분은 무관수(無灌水), 7월 15일 탁수(濯水), 8월 15일 관수(灌水), 2회 관수(灌水)의 순으로 함량이 감소하였으며 양토보다 사양토가 토양수분의 변화가 큰 것으로 나타났다. 2. 토성별 지상부 생육을 보면 출아기는 장마보다 단마의 경우 토성과는 무관하게 6~8일 정도 빠른 편이었으며 개화기, 영여자착생기는 양토보다 사양토에서 빠른 경향이었으며, 영여자 착생량은 단마, 장마 모두 괴근 형성기와 괴근 비 대기 2회 관수(灌水)에서 무관수(無灌水)보다 2배 정도 많이 착생되었다. 3. 지하부 생육을 보면 분기(分岐)는 단마가 장마보다 많았으며, 괴근중은 장마와 단마의 품종간 차이는 다소 있었으나 사양토에서 증가하는 경향을 보였다. 4. 괴근수량은 장마가 단마보다 높은 수량성을 보였으며 토성별로는 사양토보다 양토에서 수량이 증가하는 경향을 보였다.

점적관수(點滴灌水) 재배(栽培)가 양파의 채종량(採種量)에 미치는 영향(영향)을 구명(究明)코자 시험(試驗)하였던바 그 결과(結果)를 요약(要約)하면 다음과 같다. 1 생육형질(생육혈질)로서 분약수(分藥數), 엽수(葉數), 초장(草長), 엽견장(葉堅長) 관화율(關花率)은 2월(月)-3월(月) 비닐하우스피복구(被覆區)와 3월(月) 비닐하우스 피복구(被覆區)에서 점적관수(點滴灌水)로 재배(栽培)할때에 가장 양호(良好)하였다. 2. 채종량(採種量)의 구성형질(構成形質)로서 화륜경(花輪梗핵), 화경당(花梗當) 소화수(小花數), 임실율(稔實率)은 2월(月)-3월(月) 비닐하우스 피복구(被覆區)나 3월(月) 비닐하우스 피복구(被覆區)에서 점적관수(點滴灌水)로 재배(栽培)할때에 가장 양호(良好)하였기에 채종량(採種量)도 가장 많았다.