• Asian-Australasian Journal of Animal Sciences
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• v.13 no.5
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• pp.630-635
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• 2000

Previous research has not evaluated the effects of various rates and frequencies of manure application and frequencies of cutting on yield and stand persistence of cool-season grasses and alfalfa-grass mixtures. The primary objective of this study was to compare the effects of cutting management systems on herbage yield and stand persistence of orchardgrass (Dactylis glomerata L.) and an alfalfa (Medicago sativa L.)-orchardgrass mixture from various rates and frequencies of dairy slurry application. A randomized complete block design with treatments in a sub-subplot arrangement with four replicates was used. The main plot consisted of 2 cutting management systems (4 and 5 annual cuttings). The subplots were 9 fertility treatments: 7 slurry rate and frequency of application treatments, one inorganic fertilizer treatment, and an unfertilized control. The split-split-plots were the two forage species: orchardgrass and alfalfa-orchardgrass mixture. The study was initiated after 1st cutting in 1995. Cumulative yields of the 2nd and subsequent cuttings of both orchardgrass and alfalfa-orchardgrass in 1995 were higher for the 5-cutting system than the 4-cutting system. The 1995 growing season was abnormally dry. In 1996, an abnormally wet year, the reverse was true, total herbage yields being higher for the 4-cutting system than the 5-cutting system. Species response to fertility rate/frequency treatments was different in both years. Higher application rates early in the season and carryover of nutrients from late season applications the previous year appear to be responsible for the yield increases of those fertility treatments having significant yield differences between the cutting management systems. The stand ratings of orchardgrass were not affected by cutting management. In the spring of 1997, however, the stand ratings of alfalfa-orchardgrass in the 4-cutting management system were significantly greater than the 5-cutting management system. The very high manure application rate significantly reduced the stand ratings of alfalfa-orchardgrass in the 5-cutting system.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.247-247
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• 2023

Coastal lagoons play a crucial role in water exchange, water quality, and biodiversity. It is essential to monitor and understand the dynamics of hydrogeochemistry in lagoon water and its groundwater to preserve and sustainably manage the groundwater-dependent ecosystems like coastal lagoons. This study investigated the spatial and temporal hydrogeochemical characteristics of coastal lagoon (Songjiho) and groundwater on the east coast of Korea. The concentrations of major ions, water isotopes, and nutrients (nitrogen and dissolved organic carbon) in lagoon water and groundwater were periodically monitored for one year. The study revealed that major ions and total dissolved solids (TDS) concentration were higher at deeper depths of aquifers and closer to the coastal area. The hydrogeochemical characteristics of coastal lagoon and groundwater chemistry were classified into two types, Ca-Mg-HCO₃ and Na-Cl, based on their spatial location from inland to coastal area. Moreover, the hydrogeochemical characteristics of coastal lagoons and groundwater varied significantly depending on the season. During the wet season, the increased precipitation and evaporation lead to changes in water chemistry. As a result, the total organic carbon (TOC) of coastal lagoons increases during this season, likely due to increased runoff by rainfall whereas the variation of chemical compositions in the lagoon and groundwater were not significant because there is reduced precipitation, resulting in stable water levels and during the dry season. The study emphasizes the impact of spatial distribution and seasonal changes in precipitation, evaporation, and river discharge on the hydrogeochemical characteristics of the coastal aquifer and lagoon system. Understanding these impacts is crucial for managing and protecting coastal lagoons and groundwater resources.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.169-169
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• 2020

According to the IPCC analysis, severe climate changes are projected to occur in Korea as the temperature is expected to rise by 3.2 ℃, the precipitation by 15.6% and the sea level by 27cm by 2050. It is predicted that the occurrence of abnormal climate phenomena - especially those such as increase of concentrated precipitation and extreme heat in the summer season and severe drought in the winter season - that have happened in Korea in the past 30 years (1981-2010) will continuously be intensified and accelerated. As a result, the impact on and vulnerability of the water management sector is expected to be exacerbated. This research aims to predict the climate change impacts on streamflow of Daecheong Lake area of Geum River in South Korea during the summer and winter seasons, which show extreme meteorological events, and ultimately develop an integrated policy model in response. We projected and compared the streamflow changes of Daecheong Lake area of Geum River in South Korea in the near future period (2020-2040) and the far future period (2041-2060) with the reference period (1991-2010) using the HEC-HMS model. The data from a global climate model HadGEM2-AO, which is the fully-coupled atmosphere-ocean version of the Hadley Centre Global Environment Model 2, and RCP scenarios (RCP4.5 and RCP8.5) were used as inputs for the HEC-HMS model to identify the river basins where cases of extreme flooding or drought are likely to occur in the near and far future. The projections were made for the summer season (July-September) and the winter season(November-January) in order to reflect the summer monsoon and the dry winter. The results are anticipated to be used by policy makers for preparation of adaptation plans to secure water resources in the nation.

• Journal of Animal Science and Technology
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• v.45 no.2
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• pp.163-168
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• 2003

This study was carried out to estimate the effects of environmental factors on the activities and rectal temperatures(heat tolerance) of Holstein dairy cows in a summer season. An activity-meter(Alpro system$^{\circledR}$) was used to record activities of 77 cows for 24 hours. The feeding standards for milking and dry cow were formulated with concentrates and corn silages based on the NRC(1998). Cows to check temperature were kept in stanchions and temperature was checked in rectum. Ambient temperature was $29.0^{\circ}C$ between 1 p.m. and 3 p.m. of the day. The rectal temperatures were affected by parities and status of milking or dry(p<0.01). The activities recorded between 9 a.m. and 12 a.m., and between 1 p.m. and 4 p.m. were not effected by the status of lactating and dry. The rectal temperature of lactating cow was 39.0${\pm}0.03^{\circ}C$, it was higher than dry cow(38.6${\pm}0.04^{\circ}C$). A higher activity of cow under third parity at 1 p.m. to 4 p.m. was observed comparing with fourth and above. The activities were tended to decrease with an increase of parity. Rectal temperature was negatively correlated with milk compositions, which were fat, protein, solid-not-fat and total solid except lactose.

• Journal of Ginseng Research
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• v.2 no.1
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• pp.35-57
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• 1977

Seasenal absorption of inorganic nutrients and dry matter Production were studied with four-year-old ginseng plant. The residuary amounts of the nutrients supplied to ginseng Plantation were decreased with lime elapsed. The decreasing rate was greater in chemical plots than in Yacto Plots. The amounts of manure applied in this current year and growth in dry matter production of ginseng showed no signficant difference. The amounts of mineral nutrients per unit dry matter were proportional to the amounts of supplied with chemical fertilizer in the early period of growing season but with Yacto in the late season of growing. Seasonal changes of nitrogen, Phosphorus and Potassium contents per unit dry weight in each organ were high in the middle of May. They decreased sharply in the middle of June and then slowly decreased in both leaves and stems but gradually increased in roots. The absorption ratio of nitrogen to Phosphorus (N/P) was high, and that of nitrogen to Potassium (N/K) was few. The amounts of nitrogen, phosphorus and Potassium in leaves became lower with increasing the relative light intensity, but in stems, the concentrations were different with the kind of mineral nutrients. The requisite amounts of mineral nutrient of ginseng plant were 8.3∼9.9 kg of nitrogen, 1.2∼1.5 kg of phosphorus, 6.4∼7.9 kg of potassium Per 10 a for five years.

• Journal of Bio-Environment Control
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• v.28 no.1
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• pp.9-15
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• 2019

This study aimed to examine the effects of different degrees of defoliation during harvest season on hydroponically cultured 'Seolhyang' strawberry's fruit characteristics, plant growth, and changes in nonstructural carbohydrates, and find an effective defoliation method. On November 29, 2013, some of the 'Seolhyang' leaves were non-defoliated and the others were defoliated remaining 9 and 5 leaves. The number of fruits and fruit weight were not significantly different in the first flower cluster but in the second, third, and fourth flower clusters decreased as the level of defoliation increased. The soluble solids content and acidity of fruits decreased in all the clusters as the level of defoliation increased. The leaf area and leaf dry weight of strawberry plant in all the treatment groups decreased from January to March and root dry weight sharply decreased during February. Thereafter, during April, the growth of plant increased. As defoliation increased, the dry weight of fruits, flower clusters, crowns, and roots decreased, and during late growing period, difference in dry weight according to the degree of defoliation was considerable. The content of carbohydrate was greater in the leaves than the fruits excepting January 30 and February 28, 2014 and in the case of strawberry plant that continuously produce fruits, the content of carbohydrate decreased in the leaves and roots. As defoliation increased, the content of carbohydrate in fruits, flower clusters, crowns, and roots decreased. Defoliation for strawberry plants is carefully done during harvest season. Twelve leaves during December and 14 leaves from January to March should be maintained, and in April when the number of leaves increases, old leaves should be defoliated.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.297-300
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• 2006

Various buildings constructed by environmentally friendly resources are being built in KOREA. Especially the building made by the wood, which has environmental characteristics that the reinforced concrete and brick doesn't have, are acknowledged with its superiority. Then, studies on indoor thermal control capability of the wooden building and influence of its indoor environment to sensory environment of occupants are not enough proceed. Thus, there were proceeded 24 hours measurements for indoor and outdoor thermal environmental elements of Log Cabins and the hourly subjective tests to evaluate indoor amenity of occupants in this study. The results of the study are following: 1) Upon evaluation on thermal environment elements, indoor and outdoor dry bulb temp were 22.0$^{\circ}C$ and -2.9$^{\circ}C$, and Indoor and outdoor average relative humidity were 25.8%and 52.7%. Differences of indoor and outdoor temperature and humidity were 24.9$^{\circ}C$ and 26.9%. 2) Upon contrastive analysis between the results of subjective tests, warm and cold sensation vote, and PMV (Predicted Mean Vote) and PPD (Predicted Percent Dissatisfaction), values of subjective tests W.9

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.4
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• pp.381-387
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• 1996

An experiment was carried out for 12 weeks to study the feeding behaviour, growth and carcass characteristics of cross-bred goats. Nine bucks with an average live weight of $18.02{\pm}0.9kg$ were allocated in a completely randomized block design arrangement, consisting of three feeding regimes and three blocks. The feeding regimes consisted of 100% natural grass (Treatment A), 100% gliricidia leaf (Treatment B) and 100% ficus leaf (Treatment C). Frequency of turning-over and sniffing the feed and duration and frequency of ruminating, defaecating, and urination of goats in treatment B were longer, while duration of masticating and jaw movement of chewing one bolus was shorter than those of goats in treatments C and A (p < 0.05). Furthermore, goats in treatment B gained more live weight, consumed more feed, consumed less water and was more efficient in utilizing the feed than goats in treatments C or A (p < 0.05). The dressing percentage, carcass length and carcass fat of goats in treatment B were higher and their bone percentages were lower than those in treatments C and A (p < 0.05). There is an indication that feeding gliricidia and ficus leaves during the dry season could not only increase the body weight and improve carcass quality of the goat but also save water for household needs.

• Journal of Environmental Science International
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• v.15 no.12
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• pp.1125-1139
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• 2006

The cluster analysis of diurnal precipitation patterns is performed by using daily precipitation of 59 stations in South Korea from 1973 to 1996 in four seasons of each year. Four seasons are shifted forward by 15 days compared to the general ones. Number of clusters are 15 in winter, 16 in spring and autumn, and 26 in summer, respectively. One of the classes is the totally dry day in each season, indicating that precipitation is never observed at any station. This is treated separately in this study. Distribution of the days among the clusters is rather uneven with rather low area-mean precipitation occurring most frequently. These 4 (seasons)$\times$2 (wet and dry days) classes represent more than the half (59 %) of all days of the year. On the other hand, even the smallest seasonal clusters show at least $5\sim9$ members in the 24 years (1973-1996) period of classification. The cluster analysis is directly performed for the major $5\sim8$ non-correlated coefficients of the diurnal precipitation patterns obtained by factor analysis In order to consider the spatial correlation. More specifically, hierarchical clustering based on Euclidean distance and Ward's method of agglomeration is applied. The relative variance explained by the clustering is as high as average (63%) with better capability in spring (66%) and winter (69 %), but lower than average in autumn (60%) and summer (59%). Through applying weighted relative variances, i.e. dividing the squared deviations by the cluster averages, we obtain even better values, i.e 78 % in average, compared to the same index without clustering. This means that the highest variance remains in the clusters with more precipitation. Besides all statistics necessary for the validation of the final classification, 4 cluster centers are mapped for each season to illustrate the range of typical extremities, paired according to their area mean precipitation or negative pattern correlation. Possible alternatives of the performed classification and reasons for their rejection are also discussed with inclusion of a wide spectrum of recommended applications.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.2
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• pp.195-200
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• 1995

The design of this field experiment was a completely randomized block arrangement, consisted of 16 treatments (Gliricidia sepium provenances) and 6 blocks as replications with 12 plants per provenance. Of the 16 gliricidia provenances, six were from Mexico (M), four were from Guatemala (G), and one each was from Colombia (C), Indonesia (I), Nicaragua (N), panama (P), Costa Rica (R), and Venezuela (V). After 12 months establishment the gliricidia were lopped regularly 4 times a year, twice during the 4 months wet season and twice during the 8 months dry season at 150 cm height. There was variation (p < 0.05) in stem elongation from 22 to 80 cm, leaf retained from 118 to 209%, branch number from 13 to 24, fodder yield from 1,015 to 1,671 g DW/plant and wood yield from 792 to 1,662 g DW/plant among the provenances; and such variations were affected by the seasons. Belen (N14), Retalhuleu (G14) and Bukit Bali (I) provenances were ranked first, second and third, respectively, measured in terms of leaf retention, stem elongation, fodder and wood yields during the wet and dry seasons.