• KOREAN JOURNAL OF CROP SCIENCE
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• v.8 no.1
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• pp.69-81
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• 1970

1. Four soybean varieties in pure stand and mixtures were grown in 20 competition treatments of genotypes at within-row spacings of 5, 10, 20, 40, and 80 cm and were investigated in 10 characters for different genotypes. 2. Yield, weight of 100 seeds, height, number of branches, pods per plant, and seeds per pod were highly significant for within-row spacing treatment. 3. There was no spacing treatment effect for number of nodes and days to flower. Maturity did not respond equally in four varieties for spacing effect. 4. Fruiting period was influenced by spacing treatment. Height and number of branches were increased as within-row spacings were increased. Seed yield per area was increased oppositely. 5. Difference between fertilizing and non-fertilizing treatment was not significant in this experiment. At 80 cm spacing no competition effect occurred for yield. 6. In the competition effect, Kumkang Daerip was strong competitor ani Chungbuck Back and Shelby were weak competitors. 7. The within-row spacing of uniformity in roder to increase yield per area was proved as 20 cm in this study. 8. Oil percent was increased as spacings were increased and protein percent was as spacings were decreased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.340-344
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• 1991

This study was investigated to find out the optimum planting densities fo Solanum njrum L. about growth characters. yield components and yield at 6 planting densities by direct sowing culture. The results obtained are summarized as follows: Studying the correlationship. the highly negative significances were found between planting densities and fresh eights weights per plant, on the other hand, the highly positive significances were found between planting densities and plant height. Plant height was long in dense planting, and short in spacious planting by direct sowing culture. Stem diameter was thick in spacious planting. and was thin in dense planting. Fresh wt. per plant was decreased in dense planting and was increased in spacious planting by direct sowing culture. Yield was highest in dense planting densities (10 x 20cm : 50plants/$m^2$) by direct sowing culture. Fertilizing ((N： P$_2$O$_{5}$ $K_2$O=6 : 6 : 6Kg/10a) was increased than without fertilizing because plant height and number of branch was good.d.

• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.331-338
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• 2009

This present study was conducted to investigate photosynthetic characteristics, chlorophyll fluorescence, chlorophyll contents, and growth performances of containerized seedling and bare root seedling of Quercus acutissima growing under different fertilizing schemes. Both of containerized seedling and bare root seedling of Quercus acutissima showed good photosynthetic capacity and apparent quantum yield in the seedlings applied with one gram refining fertilizer (each of N, P, and K is 19%) diluted in one liter water. And chlorophyll contents also showed higher in the seedlings applied with the above fertilization scheme. The seedlings also showed good relative growth performances of root collar diameter, seedling height, total biomass, and leaf area in the some treatment scheme. In most of the treatments, containerized seedlings showed better photosynthetic capacity, apparent quantum yield, chlorophyll contents, and growth performances than bare root seedlings.

• Korean Journal of Environment and Ecology
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• v.20 no.1
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• pp.70-74
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• 2006

To study for proper growing conditions of Hydrangea macrophylla var. acuminata, used as ornamental trees or sources of natural sweetenings and biological active compounds, two-year-old cuttings of the plant were subjected to different conditions, light intensity, watering, and fertilizing levels. Photosynthetic rates measured on October 2 differed significantly between two light intensity regimes, but the values measured on September 3 were not significantly different. Mean photosynthetic rates on the plot watered three times a week were higher than the cuttings on the plot watered once a week. Mean photosynthetic rates on the plot fertilized 200grams/cuttings were slightly higher than those of the cuttings on the control plot. Chlorophyll contents measured on August 2 and on September 3 were significantly different between the light intensity regimes. Chlorophyll contents measured on August 2 were significantly different between the moisture regimes, but not significantly different between the fertilizing levels. Means of leaf growth(length and width) measured the highest values on the plot watered three times a week, and on the plot in full-sun lighted.

• Journal of Biosystems Engineering
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• v.27 no.1
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• pp.25-32
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• 2002

This study was conducted to develop a dry paddy seeder of strip tillage. The prototype is 8 rows drill seeder, which is composed of a strip tillage, sowing and fertilizing device, and pressing wheels to do the strip tillage, sowing, fertilizing, and draining ditch, simultaneously. The performances of prototype was evaluated through the investigation of fuel consumption, tillage torque, ratio of soil breaking, and economical efficiency and the results were compared with these of a dry paddy seeder that needs whole tillage. According to the USDA textural classification, the experiment field was composed of sandy loam which consisted of 56.8 of sand, 30.2 of silt and 13.0 % of clay, respectively. Its hardness ranged from 952 to 1,673 kPa depending on the soil depth, and its soil moisture content was 24.9%(d. b.) Fuel consumption of the prototype was 5,015g/hr at 2,000 rpm of engine, which was consequently 64% smaller than that of the conventional dry paddy seeder. For the tillage torque, it ranged from 132 to 206N$.$m depending on the tillage pitch, which was 10∼30% smaller than that of the conventional dry paddy seeder. The ratio of soil braking of the prototype was 87∼98%, whereas that of the conventional dry paddy seeder was 80∼97%. The working performance of the prototype was surveyed to be 3.8hours/ha, which was about 5 times higher than that of the conventional dry paddy seeder. The cost reduction of 26.3% was obtained by using the prototype.

• Korean Journal of Medicinal Crop Science
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• v.23 no.2
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• pp.150-154
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• 2015

Physiological disorders such as symptoms in leaf colored with brown spots are so many occurred in ginseng garden cultivated with paddy soil. This study was carried out to inhibit the symptoms of brown-colored leaf in 3-year-old ginseng by fertilizing calcium hydroxide [$Ca(OH)_2$] of 100 ~ 400 kg per 10a on paddy soil before transplant of seedling. Soil pH was rapidly increased, while Fe was decreased in soil by the increase of application level of calcium hydroxide. Soil pH was increased from 4.53 to 6.18 when calcium hydroxide was fertilized at level of 100kg per 10a. The content of Fe in ginseng leaf was decreased more than the control by fertilizing calcium hydroxide in soil. Ratio of brown-colored leaf and plant height and leaf area were decreased by the increase of calcium hydroxide. Ratio of survived root and yield of root showed the peak at the application level of 100 kg per 10a, and both of them were gradually decreased by the increase of calcium hydroxide. The decrease of missing plant rate above the application level of 200 kg per 10a had a negative effect on the decrease of yield of root.

• Korean Journal of Organic Agriculture
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• v.12 no.4
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• pp.411-425
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• 2004

The aim of this experiment was to investigate the effects of applying times and dilution rates of cattle slurry with water on dry matter yields and feed values of orchard grass. Cattle slurry was applied at the rates of average nitrogen fertilizer equivalent to 150kg/ha/year in 3 cutting frequency. Significantly higher dry matter yields than that of no fertilization (7.36 ton DM/ha) were recorded in the application of diluted cattle slurry (10.74~13.54 ton DM/ha) (p<0.05). Especially, this tendency was shown with higher annual dry matter yields at the partitioned dressing times, such as at the applications for 1st and 3rd growth, 2nd and 3rd growth, and 1st, 2nd and 3rd growth respectively. The yields of annual dry matter at fertilizing phosphorus, potassium and nitrogen were higher than no fertilization as 12.42 tons per ha. However, with application of diluted cattle slurry, dry matter yields per year (11.96 ton DM/ha) were significantly higher than those of fertilizing phosphorus and potassium (7.52 ton DM/ha) (p<0.05). The efficiencies of dry matter production with mineral and cattle slurry nitrogen application (kg DM/kg N) were 32.7 and 13.4~26.9kg DM/kg N respectively. Especially, these tendencies were higher in diluted application plots than in no-diluted application plots of cattle slurry. The contents of crude protein (CP, %), neutral detergent Eber (NDF, %), acid detergent fiber (ADF, %), annual yields of CP (kg/ha) and total digestible nutrient (TDNY, kg/ha) of orchardgrass were significantly higher at the application of diluted cattle Slurry than those at non-fertilizer application (p<0.05).

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.4
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• pp.13-21
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• 2021

The feasibility of HWS for agricultural use was analyzed through a crop cultivation test to utilize the hydroponic waste solution (HWS) generated from the nutriculture greenhouse. The fertilizing effect of HWS was assessed on the basis of the inorganic nitrogen (N) mostly existed in HWSs, and nitrogen (urea) fertilizer. Lettuce was selected as the target crop influenced by the soil treatment and also for the crop cultivation test. Thus, the change in growth characteristics of lettuce and that in chemical characteristics of the soil were investigated. In terms of the growth of lettuce, the C control group with 70% nitrogen (urea) fertilizer and 30% HWS and the D control group with 50% nitrogen (urea) fertilizer and 50% HWS were more effective than the practice control group (B) with 100% nitrogen (urea) fertilizer. The results of this study confirmed the combined applicability of the chemical fertilizer and HWS for crop cultivation. Because NO₃-N present in HWS has a high possibility of leaching into the soil, its applicability as a fertilizer has been considered to be relatively low in Korea. However, if an appropriate mixing ratio of urea fertilizer and HWS could be applied, the problems associated with leaching of nitrate nitrogen could be reduced with beneficial effects on crop cultivation. Thus, future studies are required on the treatment effect of HWS with repeated cultivation, impact assessment on the surrounding environment, and appropriate fertilization methods using nitrogen (urea) fertilizer and HWS. These studies would facilitate the sustainable recycling of HWS.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.3
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• pp.193-201
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• 2022

Subgroups of sperm which share similar motility features documented in mammals indicate between-subject variations that might be related to fertilizing potential of the respective ejaculates. The objectives of this study were to define subpopulations of motile sperm in Gyr falcon semen using kinematic parameters driven by Computer Assisted Semen Analysis (CASA) and to investigate the subject-related variations in these subpopulations. A total of 24 fresh ejaculates from 6 falcons were used to assign each of the 20473 sperms into 3 subpopulations by a multivariate cluster analysis. The proportion of sperms in different sub-populations were compared among subjects by a generalized linear model and repeatability of sperm frequency in different subpopulations was investigated by corelation analysis. The resulting 3 categories of sperm indicated significant differences in all kinematic parameters (p < 0.05). Subpopulation 1 (15.91%) contained sperms with the highest velocity and progressiveness of movement trajectory while subpopulation 3 (6.4%) included the least progressively motile sperms. Proportion of rapid and medium progressive sperm were consistently higher in the ejaculate of three falcons compared to the two other birds which also had the highest proportion of slow non-progressive sperms (p < 0.05). Respective proportion of sperms in each subpopulations indicated significant repeatability over multiple measurements (p < 0.05). In conclusion, subpopulations of motile sperm in Gyr falcon can be identified using kinematic parameters generated by CASA. Individual differences in the proportion of these subpopulations might have potential application for identifying the males with higher fertilizing capacity.

• Korean Journal of Animal Reproduction
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• v.10 no.1
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• pp.109-120
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• 1986

This study was conducted to define the effect of addition of lysolecithin (LC) and 20% v/v rabbit serum to sperm preincubation medium on the induction of acrosome reaction (AR) an fertilizing ability in vitro of LG-added sperm. Ejaculated rabbit sperm from New Zealand White buck was washed once by centrifugation, then preincubated for 2 or 4 hrs in a chemically defined medium (DM), DM plus 20% rabbit serum or BSA-free DM plus 20% rabbit serum at 37$^{\circ}C$ water bath or CO2 incubator. At the end of preincubation LC was added to the preincubated sperm, which was stained at 0.5 to 4 hr later and examined for AR and sperm motility. For in vitro fertilization, gametes were coincubated in DM up to 24 hrs and thereafter fertilized embryos were incubated in BSM -II up to 48 hrs. Addition of LC to 4-hr preincubated sperm was more effective for the AR and sperm motility than that to 2-hr preincubated sperm and optimal concentration of LC for AR was about 80${\mu}$g/ml. A significant increase in AR occured from 20 to 30 min. after addition of 80 to 100${\mu}$g/ml in 4-hr preincubated sperm. BSA-free DM plus 20% rabbit serum showed a higher AR and sperm motility than those of DM plus 20% rabbit serum in LC-added sperm after 4-hr preincubation. The incidence of AR after 4-hr preincubation and at 30 min after 60${\mu}$g/ml LC addition varied greatly among individual bucks. Sixty ${\mu}$g/ml LC-added sperm showed a slight high cleavage rate over control levels, but 100${\mu}$g/ml LC-added sperm showed lower cleavage rate rather than 60${\mu}$g/ml LC. It is concluded that optimal concentration of LC for high AR induction and sperm motility in 4-hr preincubated sperm was about 80${\mu}$g/ml, but 60${\mu}$g/ml level was more useful for in vitro fertilization.