• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.333-333
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• 2017

This study was conducted to establish of cropping system for year-round forage crops production in east-southern part of Korea and investigated their productivity and feed values. Cropping systems were tested in experiment using oat (cv. Highspeed and Darkhorse) in spring and autumn season, corn (cv. Kwangpyeongok) and sorghum (ss-450) in summer season and rye (cv. Gogu) and triticale (cv. Joseong) in winter season. Considering the forage productivity and feed value such as acid detergent fiber (ADF), neutral detergent fiber (NDF) and total digestive nutrients (TDN), this result suggest that three cropping system for year-round forage crops production. The combinations with triticale (winter), corn or sorghum (summer) and oat (autumn) were would be suitable ones. And also the combinations with rye (winter), corn or sorghum (summer) and oat (autumn) were would be suitable. If forage crops cultivation was started in spring season, the combinations with oat (spring), oat (autumn), triticale or rye (winter), corn or sorghum (summer) and oat (autumn) were would be appropriable. For the more suitable cropping system, we are proceeding on verification experiment of year-round forage crops.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.346-346
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• 2017

In Northern Laos, maize is cultivated in continuous cropping without fertilizer, fallowing nor any other soil conservation practice. It is expected that this inadequate management in maize cultivation will degrade soil and decrease yield. However, there is limited information about the change of soil condition and yield under continuous maize cultivation. We tried to evaluate the change of soil condition and yield under continuous maize cultivation in Northern Laos. Our study was conducted in farmer's flat and slope fields in Sainyabuli province where maize cultivation had been introduced earlier than the other provinces of Northern Laos. Our study was conducted in 21 fields in 2014, and in 19 fields in 2015. We analyzed grain yield and soil characteristic (total carbon (TC), total nitrogen (TN), available phosphorus (Av-P), exchangeable cation, pH, soil texture) at 3 places in each field. The 3 places were set at different elevation level (lower position, middle position, upper position) in slope fields. Further, the period of continuous maize cultivation and crop management practice were investigated. Then, by evaluating the relation between the period of continuous maize cultivation and yield and the soil characteristics, the effect of maize cultivation was estimated. Crop management practices were similar among the investigated fields. Maize was cultivated in rain season. Grain seed and cob were harvested on September or October, but shoot was left on the fields. No crop was cultivated during dry season. Fertilization and fallowing has never been conducted under continuous maize cultivation. On the other hand, the period of maize cultivation was different among the fields, and ranged from 2 years to 30 years. In the slope fields, as the period of continuous maize cultivation was longer, the contents of TC and TN were lower at all 3 positions, Av-P content was lower at the upper position, exchangeable potassium (Ex-K) content was lower at the middle and the upper positions. The other soil characteristics weren't related with the period of maize cultivation in the slope fields. In contrast, soil characteristics weren't related with the period of maize cultivation in the flat fields. Yield was lower as the period of maize cultivation was longer at the upper position of the slope fields. At middle position of slope fields, yield tended to be low with increase of the period of maize cultivation. In contrast, yield wasn't related with the period of continuous maize cultivation in flat fields. From the results about crop management, it was presumed that the period of maize cultivation was one of the main factors causing the difference of yield and soil characteristics among the fields. Therefore, from the result of yield and soil condition, it was considered that the continuous maize cultivation decreased soil productivity in the slope fields with decline of TC, TN, Av-P, Ex-K and yield at upper position of slope fields, and decline of TC and TN in the other positions in Sainyabuli province.

• Journal of Marine Bioscience and Biotechnology
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• v.4 no.1
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• pp.24-30
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• 2010

Species Kappaphycus alvarezii (Doty) Doty, Kappaphycus striatum (Schmitz.) Doty and Eucheuma denticulatum (N. L. Burman) Collins et Harvey, which was brought to Vietnam from Japan in 1993 and Coco island, Martan Sea, Cebu, Philippines in 2005 have been cultivated in the different coasts of South Central Vietnam. Their growth rates and physical properties of carrageenan, then, were analyzed. The obtained results showed that the growth rate of E. denticulatum and K. striatum strains is higher than those of K. alvarezii. Species of K. striatum could grow over wide range of temperature and tolerate more strongly to high temperature compared with K. alvarezii, but their content and gel strength of kappa-carrageenan were almost the same and high. For purpose of the Kappahycus cultivation farms with stable and high production all year round (especially in the seawaters of shallow, semi-closed Lagoons where the water movement is not good and with high temperature in the hot season), mixed cropping of K. alvarezii and K. striatum as seeds stock during different cropping seasons was established. Our results suggested that K. alvarezii and K. striatum could be grown in the cool season (from Oct. to next March) with the same and high content and gel strength of kappa - carrageenan, but in the hot season need to chose K. striatum for cultivation only (from Apr. to Sept.).

• Journal of Bio-Environment Control
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• v.3 no.1
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• pp.58-65
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• 1994

It is necessary to effective temperature and humidity management for normal growth of crops in protected cultivation during the summer season. Because the highest temperature of vinyl house inhibit normal growth of crop and decrease of crop production or marketability in summer season. Finally, the vinyl house was impossible some crop cultivation in summer season. This study was conducted to investigate effective and economic method for temperature drop in protected cultivation during the summer season. 1. In medium size vinyl house(5$\times$13$\times$3m), the effect of temperature drop appeared the highest in treatment of shading with aluminium thermal curtain＋fog system＋ventilation with fan. The effect of temperature drop was about 1$0^{\circ}C$ lower than outer air temperature and about 4$^{\circ}C$ lower than outer soil temperature. 2. The effect of temperature drop according to shading with aluminium thermal curtain＋fog system＋ventilation with fan during the highest temperature of summer season Jul., 20 to Aug., 21 was appeared about 8$^{\circ}C$ lower than outdoor above ground(1.2m) and about 7$^{\circ}C$ lower than outdoor surface ground. 3. The changes of solar radiation during a day according to shading with aluminium thermal curtain＋ventilation with fan and shading with black curtain＋ventilation with fan treatments was appeared respectively about 29.3%, 32.5% of outdoor solar radiation a fine day and respectively about 27.4%, 31.8% of outdoor solar radiation a cloudy day.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.222-222
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• 2017

This study aimed to determine an optimal temperature of root zone for the chive cultivation in a greenhouse during the winter season that may raise the possibility of chive (Allium schoenoprasum L.) harvest any time year-round by reducing energy consumption. The maximum and minimum temperatures of root zone were 26.8 and $19.8^{\circ}C$ for the R-Z20, 28.3 and $23.6^{\circ}C$ for the R-Z25 and 22.4 and $14.3^{\circ}C$ for the control. The highest fresh weights of shoot and root, plant height, root length and stem diameter were observed in the R-Z20 treatment. There was no significant difference in the growth between the R-Z25 and control treatment. These results suggest that the optimal temperature of root zone is $20^{\circ}C$ for the chive cultivation in the greenhouse during winter season.

• Korean Journal of Agricultural Science
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• v.17 no.1
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• pp.18-25
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• 1990

The above results indicate that vegetable crop production using vinyl houses continously increases. However, technical support and facility improvement are still insufficent to establish a full production system. In order to improve the cultural environment in facilities for better vegetable culture, several facters should be considered. 1. Facility design and arrangement should be made to improve micro-environments for crop growth and development because direction of facility and covering materials can affect the amount of light trasmitted into vinyl houses. 2. Cultivation of several leading varieties in each crop may not provide stable production and profit especially under undesirable environmental conditions. Thus, it is required to grow not only leading varieties but also other cultivars to decrease the economic losses. 3. Crops should be carefully managed when planted in early season not to experience low temperatures which induce growth retards. Early season cultivation requires proper selection of cultivars which are resistant to low temperture. 4. Active control of micro-environment in facilities should be made via improving the ventilation and irrigation systems.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.1021-1030
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• 1996

The mechanism of the mulch film cutter assembly designed as an integral part of a rice transplanting device was developed for mulching cultivation of early season culture rice. This mulch film cutter assembly was directly attached to the transplanting device of the rotary type Japanese transplanter. The principle is that the knife cut a planting slit on the polyethylene film while the planting finger immediately plants seedling into the soil through the planting slit. Computer results implied that the knife of the mulch film cutter assembly can make appropriate planting slit on the polyethylene film as the planting finger effectively plants the seedlings into the paddy soil through the same planting slits.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.2
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• pp.27-35
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• 2022

Based on the current status of groundwater usage in the dry season through field surveys, this study tried to suggest countermeasures to reduce groundwater usage and to improve the water quality of baseflow from agricultural fields. For this purposes, basins with water curtain cultivation preceded were targeted where decreases of groundwater due to continuous use of groundwater in spring and winter annually observed. From monitoring groudwater usage of the study watershed, 130,058, 130,105 m³/day of water was pumped in during the water curtain cultivation period (October-February) in the Shindun, Seokwon watershed respectively. And the pilot application of the smart automated sensor-based water curtain cultivation system (smart WC system) developed in this study to reduce groundwater consumption has been conducted. As a result, the efficiency of the smart WC system when threshold temperature is set as 6.3 ℃ was 21.1% compared to conventional cultivation and efficiency increased as threshold temperature gets lower. Lastly, in this study, culvert drainage and Bio-filters were installed and rainfall monitoring was performed 15 times in order to analyze the baseflow securement and pollutant loads behavior. As a result, the test-bed with culvert drainage and Bio-filter installed together generated 61.4% more baseflow (4.974 m³) than the test-bed with only culvert drainage was installed (3.056 m³). However, the total pollutant load of all water quality contents (BOD, COD, T-N, TOC) except for the SS and T-P was found to be greater in the culvert drain and Bio-filter installed than in the culvert drain test-bed.

• Journal of Practical Agriculture & Fisheries Research
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• v.13 no.1
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• pp.139-151
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• 2011

• KOREAN JOURNAL OF CROP SCIENCE
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• v.23 no.2
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• pp.126-132
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• 1978

To examine the effects of P.E. film and rice straw mulching on fall grown potato(Shimabara cultivar) in the middle region of Korea, sprouted seed tuber pieces were transplanted with six kinds of mulching treatments on 24th July and harvested on 25th October. P.E. film mulching from transplanting resulted the perfect rot of transplanted seed pieces due to the excessive high soil temperature (noon soil temperature of about 4$0^{\circ}C$ continued until the middle of August). P.E. film mulching from 15th September to harvest increased the marketable tuber yields by 35% due to the raising of soil temperature by 1-3$^{\circ}C$ and maintaining of available soil moisture in dry season. Rice straw (whole or cut in 10cm length) mulching lowered the soil temperature in hot season and raised it in cool season and maintained available soil moisture in dry season. Therefore better emergence, growth and yields were induced. Effects of whole straw, whole growing season and thicker mulching were greater than cut straw, half growing season and thinner mulching. 6cm mulching of whole or cut straw during whole growing season resulted the increasing of marketable tuber yields by 56 or 48%.