• 한국농공학회논문집
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• 제63권3호
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• pp.75-85
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• 2021

This study evaluated variations in the paddy rice water demand based on the continuous changing in rice transplanting period and ponding depth at the four study paddy fields, which represent typical rice producing regions in Korea. Total 7 scenarios on rice transplanting periods were applied while minimum ponding depth of 0 and 20 mm were applied in accordance with maximum ponding depth ranging from 40 mm to 100 mm with 20 mm interval. The weather data from 2013 to 2019 was also considered. The results indicated that the highest rice water demand occurred at high temperature and low rainfall region. Increased rice transplanting periods showed higher rice water demand. The rice water demand for 51 transplanting days closely matched with the actual irrigation water supply. In case of ponding depth, the results showed that the minimum ponding depth had a proportional relationship with rice water demand, while maximum ponding depth showed the contrary results. Minimum ponding depth had a greater impact on rice water demand than the maximum ponding depth. Therefore, these results suggest that increasing the rice transplanting period, which reflects the current practice is desirable for a reliable estimation of rice water demand.

• 한국토양비료학회지
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• 제49권5호
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• pp.564-571
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• 2016

As the amount of rice straw collected increases, green manure crops are used to provide the needed organic matter. However, as green manure crops generate methane in the process of decomposition, we tested with different tillage depths in order to reduce the emission. The atmosphere temperature of the chamber was $25{\sim}40^{\circ}C$ during the examination of methane and soil temperature was $2{\sim}10^{\circ}C$ lower than air temperature. The redox potential (Eh) of the soil drastically fell right before irrigated transplanting and showed -300~-400 mV during the cultivating period of rice (7~106 days after transplant). When hairy vetch was incorporated to soil and the field was not irrigated, the generation of methane did not occur from 12 to 4 days before transplanting rice and started after irrigation. Regarding the pattern of methane generation during the cultivation of rice, methane was generated 7 days after transplanting, reached the pinnacle at by 63~74 days after transplanting, rapidly decreased after 86~94 days past transplanting and stopped after 106 days past transplanting. When tested by different soil types, methane emission gradually increased in loam and clay loam during early transplant, whereas it sharply increased in sandy loam. The total amount of methane emitted was highest in sandy loam, followed by loam and clay loam. In all three soil types, methane emission significantly reduced when tillage depth was 20 cm compared to 10 cm. The rice growths and yield were not affected by tillage depth. Therefore, reduction of methane emission could be achieved when application hairy vetch to the soil with tillage depth of 20 cm in paddy soil.

• 한국잡초학회지
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• 제14권2호
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• pp.101-106
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• 1994

수경재배(水耕栽培)와 폿트실험을 통하여 벼에서 이앙심도(移秧深度), 묘령(苗齡) 및 토성(土性)에 따른 Dithiopyr의 약해정도(藥害程度)를 검정(檢定)하였으며 벼에서 상기(上記) 요인(要因)에 따른 벼의 $^{14}C$-dithiopyr 흡수량(吸收量)을 측정(測定)하여 벼의 Dithiopyr 약해발생(藥害發生) 기구(機構)를 구명(究明)하였다. 1. 벼는 이앙심도(移秧深度)가 얕고 엽령(葉齡)이 어릴수록, 그리고 양토(壤土)나 사양토(砂壤土)에 비하여 사질토양(砂質壤土)에서 약해정도(藥害程度)가 더 심한 경향(傾向)이었다. 2. Dithiopyr의 흡수량(吸收量)은 벼의 이앙심도(移秧深度) 2, 3cm, 보다 0cm에서 그리고 엽령(葉齡) 2엽기(葉基)보다 3, 4엽기(葉基)에서 더 많았다. 그리고 사질양토(砂質壤土)은 사양토(砂壤土)나 양토(壤土)에 비하여 흡수량(吸收量)이 많은 경향(傾向)이었다. 3. 따라서 사질양토(砂質壤土)과 이앙심도(移秧深度)가 얕거나 뜬묘(苗)가 생긴 경우(0cm)에는 벼의 Dithiopyr 흡수량(吸收量)이 많기 때문에 벼의 약해발생(藥害發生)이 높은 것으로 사료(思料)되었다.

• Journal of Biosystems Engineering
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• 제5권1호
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• pp.58-65
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• 1980

Sinkage differences between the wheels of a transplanter which are caused by the different hard pan of fields and land preparation affect the field performance of a rice transplanter. In this experiment the relationships between the sinkage differences of the wheels of a transplanter and the planting distance, planting angle, planting depth and deviation from a straight transplanting line were investigated. The objective of this experiment was to obtain some basic informations for the effective use of the rice transplanter . The results of this experiment are as follows. 1. Transplanting distance became shorter as the sinkage differences increased. This effect was greater on the side of the transplanter with a shallower sinkage. 2. The depth of transplanting increased as the differences in the depth of sinkage increase for the side with the deeper sinkage. An opposite trend was observed for the side with shallower sinkage. 3. The angle of transplanted seedlings from the vertical portion increased slightly as the sinkage differences increased. The variation in results were greater from the side of the transplanter with deeper sinkage than with shallower sinkage. 5. The best postures of planted seedling were found when the water depth was 3 cm for the side of transplanter with deeper sinkage and 4 cm for the shallower sinkage side. The relationships between the postures of planted seedling and water depth. , or $y=67.62 + 10.69x-1.76x^2$ for the side of transplanter with deeper sinkage and $y=66.64+11.62x-1.50x^2$ for the side with shallower sinkage, were found from this experiment.

• ALGAE
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• 제20권2호
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• pp.151-155
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• 2005

To obtain basic data, we investigated the effect of blade length on transplants, the transplanting method of Laminaria japonica for creating L. japonica resources and the number of transplanting plates with surviving L. japonica. The survival rate of L. japonica, blade length of transplants and drag force of transplanting plates were also researched. The number of transplanting plates with surviving L. japonica, the survival rate and blade length of 20 cm long-initial transplants were greater than those of 1.5, 5 and 10 cm long-initial transplants in an outdoor aquarium. At the depth of 4 m in the coastal waters, the number of transplanting plates with surviving transplants, the survival rate and the blade length of 30 cm long-initial transplants were higher than those of 10 and 20 cm longinitial transplants. The drag force is calculated by cording up sporophytes of L. japonica into the transplanting plates under water. The drag force in the case of a 2.18 kg-weight transplanting plate and in a current speed of 0.5 m${\cdot}s^{-1}$ for considering stability of the plate was 631.50 g to a concrete substratum on the seabed, 703.92 g to a shingle substratum, 788.00 g to a sand substratum, and 1018.30 g to a silt substratum. If we consider the stability and economic efficiency of the transplanting plate, the proper weight of the plate per one individual of 18.11 cm in blade width and 190.20 cm in total blade length is regarded as 508.2 g when it is calculated with the concrete substratum that shows the lowest drag force.

• 한국잡초학회지
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• 제10권4호
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• pp.261-268
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• 1990

배유(胚乳)의 유무차이(有無差異)에 따른 공시제초제(供試除草劑)에 대(對)한 약해반응결과(藥害反應結果) 배유유무(胚乳有無)에 따라 초장(草長), 분얼수(分蘖數) 및 건물중(乾物重)에 있어서 유의적(有意的)인 차이(差異)를 나타내었다. 즉 무배유묘(無胚乳苗)보다 유배유묘(有胚乳苗)의 약제내성(藥劑耐性)이 전반적(全般的)으로 높은 경향(傾向)이었다. 이앙심도차이(移秧深度差異)에 따른 약해유발정도(藥害誘發程度)에 있어서는 0cm의 극천식조건(極淺植條件)에서와 4cm의 심식조건(深植條件)에서 2cm의 심도(深度)에서 보다 약해(藥害)가 증대(增大)되었는데 특히 pretilachlor는 0cm 조건(條件)에서, pyrazolate는 4cm 조건(條件)에서 생육(生育)이 억제(抑制)되었으며 bensulfuronmethyl은 전반적(全般的) 으로 약해(藥害)가 유발(誘發)되었다. 처리시기(處理時期)에 따른 약해반응(藥害反應)에 있어서는 공시약제(供試藥劑) 모두에서 9 또는 12DAT 처리조건(處理條件)에서보다 초기처리시기(初期處理時期)인 3, 6DAT처리에서 약해(藥害)가 증대(增大)되었으며 특히 pretilachlor와 bensulfuron-methyl에서 생육저해현상(生育沮害現狀)이 심(甚)한 경향(傾向)이었다.

• 한국토양비료학회지
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• 제49권6호
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• pp.662-668
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• 2016

No-tillage dry-seeding of rice can offer potential benefits by reducing time and labor cost compared with conventional tillage practices. This study was conducted to investigate the effects of no-tillage dry-seeding on rice growth and soil hardness in comparison with other rice cultivation methods, machine transplanting and wet-hill-seeding on puddled paddy. The seedling stand fell within optimum range for both no-till dry-seeding and wet-hill-seeding on puddled paddy. Plant height, number of tillers and SPAD values in no-tillage dry-seeding cultivation were higher than those observed in other methods. There were no significant differences in grain yield of rice among three cultivation methods. The quality characteristics of milled rice grown in no-tillage dry-seeding were similar to those grown in other cultivation methods. Soil hardness in top 10 cm depth was significantly higher in no-tillage dry-seeding than other cultivation methods, while soil hardness below 10 cm depth was highest in machine transplanting cultivation. Results indicate that no-tillage dry-seeding practice is comparable to conventional tillage system in terms of seedling establishment, growth, yield and grain quality.

• ALGAE
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• 제20권4호
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• pp.379-388
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• 2005

Seagrass bed is an important component in coastal and estuarine ecosystems, providing food and shelter to a wide variety of fauna. Recently, seagrass coverage has declined significantly due to anthropogenic influences such as reclamation, dredging, and eutrophication and consequently, necessity of seagrass habitat restoration is rising. Transplantation experiments with Zostera marina using TERFS, staple method, and shell method have been conducted at Dadae Bay, Kosung Bay and Jindong Bay on the south coast of Korea to select an optimal transplanting method for restoration of Z. marina habitat. Three experimental sites located at the vicinity of natural Z. marina beds with an average water depth of about 4m. Z. marina plants, which were collected from donor bed in Koje Bay were also transplanted at 7 different time from October 2003 to July 2004 to find appropriate transplanting time. Density of Z. marina was monitored monthly at both transplanted areas and natural beds. Transplantation using the staple method showed the highest survival rate of transplant. Shell method was also an effective transplanting method at muddy areas in Kosung Bay and Jindong Bay, but not suitable at sandy areas in Dadae Bay. These results suggest that sediment composition of transplanting areas should be considered for the selection of the optimal transplanting method. Z. marina transplanted during fall usually showed the highest survival rate, while most Z. marina plants transplanted in summer died due to high lethal temperature during this period.

• 한국잡초학회지
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• 제11권3호
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• pp.174-177
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• 1991

이앙심도(移秧深度)를 6단계(段階)로 달리하여 벼를 이앙(移秧)하고 $^{14}C$-dithiopyr와 dithiopyr을 혼합처리(混合處理)한 다음 벼의 생육(生育) 및 흡수량(吸收量)들을 조사(調査)한 결과(結果)는 다음과 같다. 1. 무처리구(無處理區)에서 벼의 생육(生育)은 주기부(株基部)가 노출(露出)된 0, 0.25cm 이앙(移秧) 심도구(深度區)에서 가장 낮았고, 1cm와 2cm 심도구(深度區)에서 좋았다. 2. 약제처리구(藥劑處理區)간의 벼 생육율(生育率)은 무처리구(無處理區)와 동일(同一) 경향(傾向)으로 초장(草長) 및 건물중(建物中)의 경우 0cm와 0.25 cm 심도구(深度區)에서 현저히 적었고, 0.5, 1, 2, 4cm 심도구(深度區)등은 무처리구(無處理區)와 대비 큰 차이(差異)가 없었다. 근장(根長)은 0, 0.25 및 4cm구(區)에서 짧았고, 0.5-2.0cm 심도구(深度區) 사이에는 유의차(有意差)가 없었다. 3. 경엽부(莖葉部)와 근부(根部)에서 흡수(吸收)된 $^{14}C$-dithiopyr의 단위중량당(單位重量當) 함량(含量)은 0cm와 0.25cm 심도구(深度區)에서 가장 많고 0.5cm이상 1cm, 2cm로 되면서 그 양(量)이 적었으며, 생육(生育)이 진전되면서 심도(深度)간 흡수량(吸收量)의 폭(幅)이 좁아졌다. 4. Dithiopyr에 의한 이앙묘(移秧苗)의 생육억제(生育抑制)는 이앙묘(移秧苗)의 주기부(株基部)가 토양(土壤)에 묻이는 정도 이상의 이앙심도(移秧深度)(0.5cm 이상)에서는 거의 없으며, 0~0.25 cm의 극단적(極端的)인 천식(淺植)시에 생육억제(生育抑制)를 보였든 것은 수도체(水稻體)중 dithiopyr의 흡수량(吸收量)이 많았기 때문이었다.

• Journal of Biosystems Engineering
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• 제35권1호
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• pp.37-45
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• 2010

Since SRC (Short-term Rotation Coppice) such as poplar and willow can be harvested in three years, they are known to be a potential forest biomass as fuel for a power plant. The production system including transplanting and harvesting is, however, necessary to be mechanized because such a biomass should be handled in a massive volumetric size. A pull-type stem-cutting transplanter was developed in the research as the first step to realize the production of SRC. A needle-like transplanting device pushes a stem-cutting into the prepared soil bed by a pneumatic cylinder, and another device firms soil around a stem-cutting transplanted. Since this is an intermittent operation, it was necessary to develop a zero horizontal velocity mechanism which enabled only the transplanting needle part to continue a zero horizontal movement relative to the ground during the transplanting operation even when the tractor kept moving forward. The 2-row transplanter can transplant stem-cuttings at the rate of 6.5 seconds per row without missing a single attempt. The planting depth and distance were well maintained and controlled. Their CVs were between 2.1~3.4% and 0.87~1.7% for the depth and the distance, respectively. Although, the transplanted stem-cuttings tended to lean outward from the back-view and forward from the side view, they were planted within the range of $3^{\circ}$ from the upright position.