• 한국작물학회지
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• 제45권1호
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• pp.1-5
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• 2000

Leaf area is critical for crop light interception, and thereby has a substantial influence on crop yield. This experiment was conducted to characterize the development of soybean [Glycine max (L.) Merr.] leaf area. Plastochron index and leaf relative growth rate of Jackson was contrasted with the PI416937, which also has demonstrated tolerance to drought. First, plastochron ratio (PR) and plastochron index (PI) were evaluated in greenhouse to compare the leaf growth rate between two genotypes under well-watered condition. There was reasonable constancy of PR between two genotypes. The PR means of Jackson and PI416937 were 0.41 and 0.44, respectively. A fairly smooth increase of PI during vegetative stage was observed. Second, the relative growth rates were graphed against leaf area, normalized with respect to final leaf area, under well-watered and water-deficit conditions. Leaf growth was sustained longer in well-watered condition than water-deficit condition and there was a sizable proportion of leaves which was ceased earlier their growth in water-deficit condition compared to well-watered condition. The leaf relative growth rate of Jackson until leaves had completed at 45% of their growth during water deficit period was higher than that of PI416937.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.231-231
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• 2017

Drought limits rice production under upland condition. This study quantified the effect of rhizobacteria inoculation on rice root system developmental response to drought and its role in maintaining high soil water use, and dry matter production under drought using NSIC Rc192 (rainfed lowland rice variety). The source of inoculant was Streptomyces mutabilis, a recently isolated rhizobacteria containing plant growth promoting compounds such as ACC deaminase, indole-3-acetic acid and phosphatase (Cruz et al., 2014, 2015). In the first experiment, pre-germination inoculation of seeds with S. mutabilis significantly increased the shoot and root (radicle) length as well as root hair lengths, relative to the non-inoculated control. In the second experiment, rice plants inoculated with S. mutabilis and grown in rootbox with soil generally had greater total root length under drought regardless of the timing of inoculations, relative to the non-inoculated control. Consequently, improved root system development contributed to the increase in soil water uptake under drought and thus, dry matter production. Among inoculation treatments, one-time inoculation of S. mutabilis either at pre-germination or pre-drought stress at 14 days after sowing (DAS), had significantly greater shoot dry matter production than three-time inoculation at pre-germination, at thinning (3 DAS) and at pre-drought (14 DAS). This study demonstrated the effectiveness of rhizobacteria (S. mutabilis) containing growth promoting compounds for enhancing drought dehydration avoidance root traits and improving the growth of rice plants under drought condition.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.281-281
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• 2017

Recently, global warming by greenhouse gas effect is getting danger and danger for human life and agriculture at present. In Indonesia, according to heavy rain in the agriculture land is often covered by excess water in result crop growth would be affected negative. This water stress triggers roots failure in anaerobic condition for upland crop because of limiting roots respiration. Chili pepper grows in upland sometimes in touch with waterlogging due to rainfall and /or over flow water from river in Indonesia. In this case, roots growing is inhibited by effect of shortage of oxygen at root cap. Therefore, the objective of this study is to observe the plant behavior in waterlogging using mahor local genotypes (Ferosa, Laris, Romario) in Sumatra. The experiment was kept by at 1cm depth water above the soil surface as a waterlogged treatment for ---days. As a result, waterlogging affected plant growth of chili negatively, especially for roots growth. Almost roots were getting bad and changed color for brown during waterlogging. A significant negative effect for nutrient absorption by roots was found in dry weight of all varieties during waterlogging. Dry weight of roots was decreased by 81.4% and 67.6%, and those of aerial part decreased by 74% and 67.2% compared with control in Ferosa and Romario at 1week after treatment. On the other hand, dry weight of roots was decreased only 35% in Laris. Therefore, Laris has a tolerance for waterlogging compared to with other varieties. Also, Laris in SPAD value was kept initial level during waterlogging however those of Ferosa and Romario decreased. Finally, due to impact of waterlogging, it may be the roots become failure because of less aerenchyma formation under anaerobic condition. We need confirm aerenchyma formation morphologically in the future.

• Weed & Turfgrass Science
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• 제5권4호
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• pp.181-186
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• 2016

Three Echinochloa species inhabit various crop fields with different soil moisture conditions. Therefore, a growthpouch test was conducted to investigate adaptive diversity of six Echinochloa species, three from Korea and three from USA, toosmotic stress by assessing shoot and root growths. Echinochloa crus-galli var. praticola showed the greatest tolerance to osmoticstress in both root ($GR_{50}=1316.3g\;PEG\;L^{-1}$) and shoot ($GR_{50}=212.2g\;PEG\;L^{-1}$) growths, while Korean E. oryzicola was mostsensitive to osmotic stress in both root ($GR_{50}=116g\;PEG\;L^{-1}$) and shoot ($GR_{50}=126.2g\;PEG\;L^{-1}$) growths. Root to shoot (R/S) ratioof Echinochloa crus-galli var. praticola increased with increasing osmotic stress, while that of Korean E. oryzicola decreased, suggestingthat R/S ratio is closely related to osmotic stress tolerance in Echinochloa species. Our results clearly demonstrate that E. crus-galli var.praticola maintains high R/S ratio even under high osmotic stress, which enables this species to well adapt to dry upland condition. Incontrast, while E. oryzicola fails to maintain sufficiently high R/S ratio, resulting in poor adaptability to dry upland condition.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.316-316
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• 2017

The objective of this study is to estimate quantitatively soil salinity and soil loss at upland soils in agriculture land region in Saemangeum reclaimed land on the south Korea coasts. Soil loss and soil salinity are the most critical problem at reclaimed tidal saline soil in Korea. The several thematic maps of research area such as land cover map, topographic and soil maps, together with tabular precipitation data used for soil erosion and soil salinity calculation. Meteorological data were measured directly as air temperature, wind speed, solar radiation, and precipitation. The experiment was conducted 2% sloped lysimeter ($5.0m{\times}20.0m$) with 14 treatments and it were separated by low salinity division (LSD) and high salinity division (HSD) install. The cation content in ground water increased during time course, but in the case of land surface water the content was variable, and $K^+$ was lower than that of $Na^+$ and $Mg^{2+}$. At the LSD under rainproof condition, the salinity was directly proportional to soil water content, but at the HSD the tendency was no reversed. In condition of rainproof, the amount of soil salinity was higher at the HSD than at the LSD. Positive correlation was obtained between the soil water content and available phosphorous content at the rainfall division, but there was no significance at the surface soil of the rainproof division. Sodium adsorption ratio and anion contents in soil were repressed in the order of vinyl-mulching > non-mulching > bare field. According to the result of analyzing soil loss, soil loss occurred in a vinyl-mulching, a non-mulching and a bare field in size order, and also approximately 11.2 ton/ha soil loss happened on the reclaimed land area. The average soil loss amount by the unit area takes place in a non-mulching and bare field a lot. Our results indicate that soluble salt control and soil erosion are critical at reclaimed tidal saline soil and the results can provide some useful information for deciding management plans to reduce soil loss and salt damage for stable crop production and diverse utilization or cultivation could be one of the management options to alleviate salt damage at reclaimed tidal saline soil in Korea.

• 한국농공학회논문집
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• 제53권5호
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• pp.9-16
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• 2011

Curve Numbers (CN) for the combination of land use and hydrologic soil group were regionalized at Imha Watershed using Long-term Hydrologic Impact Assessment (L-THIA) coupled with SCE-UA. The L-THIA was calibrated during 1991-2000 and validated during 2001-2007 using monthly observed direct runoff data. The Nash-Sutcliffe (NS) coefficients for calibration and validation were 0.91 and 0.93, respectively, and showed high model efficiency. Based on the criteria of model calibration, both calibration and validation represented 'very good' fit with observe data. The spatial distribution of direct surface runoff by L-THIA represented runoff from Thiessen pologen at Subi and Sukbo rain gage station much higher than other area due to the combination of poor hydrologic condition (hydrologic soil C and D group) and locality heavy rainfall. As a results of hydrologic condition and treatment for land use type based on calibrated CNs, forest is recommended to be hydrologically modelled dived into deciduous, coniferous, and mixed forest due to the hydrological difference. The CNs for forest and upland showed the poor hydrologic condition. The steep slope of forest and alpine agricultural field make high runoff rate which is the poor hydrologic condition because CN method can not consider field slope. L-THIA linded with SCE-UA could generated a regionalized CNs for land use type with minimized time and effort, and maximized model's accuracy.

• 한국약용작물학회지
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• 제7권1호
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• pp.31-36
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• 1999

고추냉이 동계가온 밭재배시 allylNCS함량을 증대시키기 위하여 allylNCS함량과 밀접한 관계가 있는 것으로 알려져 있는 $SO_4^{2-}$을 함유한 함황비료를 토양과 엽면에 시비하여 생육특성, 식물체 총 황함량 및 allylNCS함량과의 관계를 조사한 결과는 다음과 같다. 생육 정체기인 월동기간동안의 가온재배로 평균기온 $14{\sim}16^{\circ}C$, 지온 $13{\sim}16^{\circ}C$로 적정 생육온도의 범위를 유지할 수 있었으며, 함황비료의 토양시용으로 토양중의 황함량은 $82.6{\sim}127.4%$까지 증가되었고 토양 pH는 황분말에서 최저 2.8까지 저하되었다. 함황비료의 처리가 지상부 및 지하부의 생육에 미치는 영향에서는 함황비료 처리로 본엽수는 감소되고 측엽수는 증가하는 경향이였으며, 근중은 황산가리 엽면시비구가 가장 양호하였고 근경중등에서는 처리간 차이가 없었다. 식물체내 총황함량은 엽면시비구 보다는 토양시용구에서 높은 경향이였고, allylNCS함량은 황분말 토양시용구에서 지상부 194%, 근경 23%의 증대효과가 있었다. 지상부의 allylNCS함량은 지상부, 근, 근경의 총 황함량과 유의한 정의 상관을 보였으며, 근경의 allylNCS함량은 지상부의 총 황함량, allylNCS함량 및 근경의 총 황함량과 유의한 정의 상관을 보였으나 분주수와는 유의한 부의 상관을 나타냈다.

• Weed & Turfgrass Science
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• 제5권4호
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• pp.247-255
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• 2016

본 연구는 전라남도 장성지역의 한국잔디 재배지의 발생 잡초를 확인하기 위하여 2014년 9월(1차 조사)과 2016년 5월(2차 조사)에 전남 장성군 삼서면 일대에서 한국잔디 재배포장을 밭 토양과 논 토양으로 구분하여 발생잡초 분포조사를 수행하였다. 잡초분포 조사결과 밭 토양에서는 27과 66종(일년생 49종, 다년생 17종)으로 일년생잡초 74.2%, 다년생잡초 25.8%의 발생을 확인하였다. 과별로 보면 국화과(Compositae)가 19.7%로 가장 많이 발생하였고, 그 다음으로 벼과(Gramineae) 13.6%, 콩과(Leguminosae) 10.6% 순이었다. 논 토양에서는 22과 69종(일년생 53종, 다년생 16종)으로 일년생잡초 76.8%, 다년생잡초 23.2% 비율의 발생을 확인하였다. 과별로 보면 국화과(Compositae)가 18.8%로 가장 많이 발생하였고, 그 다음으로 벼과(Gramineae) 14.5%, 사초과(Cyperaceae) 7.2% 순이었다. 밭 토양의 1차 조사에서는 벼과의 바랭이(8.49), 2차 조사에서는 괭이밥과의 괭이밥(7.26)이 가장 우점하였고, 논 토양의 1차 조사에서 국화과의 개망초(9.52), 2차 조사에서는 닭의장풀과의 닭의장풀(5.08)과 벼과의 뚝새풀(5.08)이 가장 우점하는 잡초종으로 확인되었다. 잡초발생 현황을 조사시기와 토양조건을 구분하여 비교한 결과 논 잡초와 밭 잡초가 혼생하는 것으로 확인되었다. 조사시기 또는 토양조건에 상관없이 공통적으로 발생하는 초종의 비율이 49.2%로 비교적 높게 나타났다. 따라서 한국잔디 재배지에서 제초제를 이용한 효율적인 방제효과를 위해서는 재배토양에 상관없이 논 잡초와 밭 잡초를 모두 잘 방제할 수 있는 약제를 선택해야 할 것으로 판단되었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.337-337
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• 2017

Accurate and optimal water supply to cereal crop is critical in growing stalks and producing maximum yields. Excessive soil moisture may cause nutrient deficiencies and oxygen deficiency. Excessive soil water during crop growth stages results in decrease of yields. In Korea, the largest agricultural lands are paddy fields. Recently, upland crops are cultivated in paddy field soils to reduce overproduced rice in Korea. In order to success this policy, it is necessary to fully understand crop response to excessive soil moisture condition from paddy field soils. Adzuki bean is one of major legumes which provide protein in daily diet. Adzuki bean has been well know its weakness to excessive soil moisture condition, In order to obtain optimal yields of adzuki bean from paddy field cultivation, it is necessary to understand response of adzuki bean under different soil moisture conditions. This study investigated characteristics of growths, yields and response degree of water stress from adzuki bean. Three cultivars were selected for this study; Chungju, Hongeon, and Arari. All adzuki beans were cultivated in a paddy field which was divided into three sections with different soil moistures. The paddy field was located in Milyang, Gyeongsangnam during 2016. One section of the paddy field had the greatest average soil moisture content as 35.1% during adzuki bean cultivation (very poor). The second greatest soil moisture section had 32.6% (somewhat poor) and the smallest soil moisture section had 28.9% of soil moisture (somewhat well). During cultivation of three cultivar adzuki beans, soil moisture contents and groundwater levels were monitored. All the characteristics of growth and yield components were measured; height, thickness, 100 seed weights etc. Stress index values were calculated by Stress Day Index (SDI). All cultivars had the greatest yields from somewhat well section. Chungju had the greatest yields throughout all three sections compared to other cultivars. Chungju had 81% greater yield than Hongeon which had the smallest yield from somewhat well section. Arari set in middle from all sections. However there was no significant differences yields from very poor and somewhat poor sections. Leaf SPAD values tended to decrease and stable carbon isotope values increased as soil moisture increased. However, Chungju had no difference across different soil moistures in SPAD and stable carbon isotope values, while Hongeon had the greatest differences across sections. These trends followed by SDI values. Chungju had the smallest SDI values compared to other cultivars, which meant that Chungju was the strongest tolerance against excessive soil moisture than other cultivars. All three cultivars showed severe decrease of yields from very poor and somewhat poor sections. Arari and Hongeon showed great decrease from somewhat well section compared to yields from upland soil. These two cultivars may not be proper cultivating in paddy fields. In conclusion, adzuki bean is very sensitive to soil moisture condition and detailed soil managements are required to obtain optimal yields of adzuki bean from paddy field cultivation.

• 한국작물학회지
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• 제44권4호
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• pp.330-338
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• 1999

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.