• Journal of Animal Environmental Science
• /
• v.8 no.1
• /
• pp.43-53
• /
• 2002

The aim of the study is to describe the fate and transformation of nitrogen in grassland ecosystems. In the growing season from 1987 to 1993, 2 growing farmer in south Germany were studied the yield and nutrient balance of reduced input slurry application. The study includes 3 different slurry application levels. The levels are conventional slurry application, reduced slurry application, without slurry application. These levels are studied at 2 different experimental farms. The forage yield of zero slurry application plot has 14∼44% of the conventional slurry application, while the yield in the reduced slurry plot is only 0∼14% lower than that in the conventional slurry plot. The kalium and phosphorus contents of forage were tend to decrease with reduced slurry application N-uptake was increasing with the increase of slurry application level. The N-uptake of zero slurry plots was lower 40∼65% of the conventional plot, while in the reduced plot was only 6∼16% lower than in the conventional plot. The N-balance shows negative figures on all plots. The N-uptake in experiment site A was only a little bit more than the N-fertilizer plot, while in site experiment B the N-uptake is 2 to 3 times higher than the N-application amount of slurry.

• Korean Journal of Agricultural Science
• /
• v.11 no.1
• /
• pp.77-84
• /
• 1984

This experiment was carried out to determine the effects of night temperature and amount of fertilization on growth and photosynthesis of red pepper plants for providing some basic imformation needed in improving the productivity of red pepper. 1. Plant height, stem length, number of flower buds, dry weight of plants and photosynthetic rate were higher in King Gun Gochu than in Dohusa, but number of leaves, number of internodes and leaf area we re higher in Dohusa compared to King Gun Gochu. 2. Plant height, number of leaves, number of flower buds, dry weight of plants, leaf area and photosynthetic rate were significantly increased by 50% increased fertilization compared to normal fertilization. 3. High night temperature($25^{\circ}C$) treatment increased plant height, stem length, number of leaves, number of internodes, number of flower buds, dry weight of plants and leaf area. 4. RGR and LAR were increased by 50% increased fertilization and high night temperature but NAR was decreased by high flower buds 5. Photosynthetic rate of King Gun Gochu was increased by 50% increased fertilization and high light intensity. 6. Number of flower buds was increased at King Gun Gochu by 50% increased fertilization and high night temperature ($25^{\circ}C$).

• Korean Journal of Environmental Agriculture
• /
• v.23 no.1
• /
• pp.7-14
• /
• 2004

This study was conducted to investigate the effect on agricultural environment and crop productivity by different amount of applied fertilizer in consideration of irrigation water quality. N, P and K contents of irrigation water used in this experiment were 6.16, 0.26 and 9.37 mg/L, respectively. N, P and K Concentrations of runoff water were lower than those of inflow water during rice cultivation. N, P and K Concentrations of ponded and percolated water were changed according to the amount and time of applied fertilization. During rice cultivation in paddy soil, nitrogen balance was closed to 0 in SFT 50% (50% level of soil testing fertilization), 0.14 kg/ha, but it was 95.3 kg/ha in CF (conventional fertilization) treatment In SW 50% and STF (soil testing fertilization) treatment yield of perfect rice was not greatly different as compared with CF treatment due to the superiority of ripening rate, 1,000 grains weight and milling characteristics. Mechanical paratability of rice was excellent in NF (non fertilization) treatment, STF 50% treatment showed higher in nutrient availability and fertilizers use efficiency than other treatments.

• Journal of Astronomy and Space Sciences
• /
• v.21 no.2
• /
• pp.141-152
• /
• 2004

Optics fabrication process for precision space optical parts includes bound abrasive grinding, loose abrasive lapping and polishing. The traditional bound abrasive grinding with bronze bond cupped diamond wheel leaves the machine marks of about $20{mu}m$ rms in height and the subsurface damage of about 1 ${mu}m$ rms in height to be removed by subsequent loose abrasive lapping. We explored an efficient quantitative control of precision CNC grinding. The machining parameters such as grain size, work-piece rotation speed and feed rate were altered while grinding the work-piece surfaces of 20-100 mm in diameter. The input grinding variables and the resulting surface quality data were used to build grinding prediction models using empirical and multi-variable regression analysis. The effectiveness of such grinding prediction models was then examined by running a series of precision CNC grinding operation with a set of controlled input variables and predicted output surface quality indicators. The experiment achieved the predictability down to ${pm}20$ nm in height and the surface roughness down to 36 nm in height. This study contributed to improvement of the process efficiency reaching directly the polishing and figuring process without the need for the loose abrasive lapping stage.

• Korean Journal of Soil Science and Fertilizer
• /
• v.33 no.6
• /
• pp.384-392
• /
• 2000

To establish N fertilizer recommended scheme for the Chinese cabbage cultivation in green house based on the soil test of nitrate nitrogen, relationship among the content of soil nitrate and fertilizer effects and fertilizer N use efficiency were investigated from nine soils which differed amount of nitrate nitrogen from $14mg\;kg^{-1}$ to$226mg\;kg^{-1}$. The amount of nitrate nitrogen in soil showed a positive correlation with the dry weight of chinese cabbage in the plot of no fertilization. When the fertilizer effects were calculated by difference between the plots of fertilization and no fertilization in the dry weight and the amount of N uptake, a negative correlation was obtained between the amount of nitrate nitrogen in soils and the fertilizer effects. There was also a negative correlation between the amount of nitrate nitrogen in soils and fertilizer use efficiency. Recommendation of application rate of nitrogen fertilizer based on content of $NO_3-N$ in soils was evaluated by the regression equation among the content of soil nitrate, fertilizer effects and fertilizer N use efficiency. Incase the content of $NO_3-N$ nitrogen in soil is more than $200mg\;kg^{-1}$, No N fertilization is recommended; However, The standard N fertilization($320kg\;ha^{-1}$) is recommended for the soils with less than $50mg\;kg^{-1}$. For the soils ranged from $50mg\;kg^{-1}$ to $200mg\;kg^{-1}$ in the amount of nitrate nitrogen, an equation has been developed in order to calculate the recommended amount of fertilizer N.

• The Korean Journal of Mycology
• /
• v.15 no.3
• /
• pp.142-148
• /
• 1987

The results investigated of the effect of light, pH, and nutrients in vitro and the levels of fertilizer(P,K and Ca) in vivo in order to find out the effect of environmental factors in forming an appressorium of Colletotrichum truncatum were as follows; The ratio of appressorium formation promoted more in a light treatment than in a dark treatment according to investigation after three and six hours passed away. But after the period, the ratio of appressorium formation promoted highly in both treatments. Reasonable pH of appressorium formation was pH 6-pH 8. The ratio of appressorium formation was the most favorable at none nutrient level in every treatment of C-source and N-source, and suppressed in a high concentration of C-source and N-source. But according as the time passed away, the ratio of appressorium formation promoted in C-source and N-source. When their quantities were increased in P and K treatments, the ratio of appressorium formation was somewhat suppressed but it was highly suppressed in the gradual order of none fertilizer level < standard fertilizer level < doubled fertilizer level in Ca treatment according to investigation after the first three hours passed away. But after the period, the ratio of appressorium formation promoted highly regardless of the level of fertilizer.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.29 no.3
• /
• pp.242-253
• /
• 1984

Four different levels of nitrogen were applied to 3 naked barley cultivars (Hordeum vulgare L.) Yonezawa, Baekdong and Yeongsanbori. Changes in physico-chemical properties were examined upon these treatments. Total protein content as well as glutelin increased as N level increased. Baekdong contained the highest protein content (13.7%) at N$_2$. Yonezawa and Baekdong contained more lysine than Yeongsanbori. Increased lysine was measured in all cultivars by increased nitrogen application. Among all amino acids proline was the highest in all cultivars, and its increase was paralled to the N levels. Magnesium and potassium were declined and calcium was increased with increased levels of nitrogen fertilizer. Ash content was decreased as nitrogen increased and as the plants have become matured. Three minutes pearling in Yonezawa was not sufficient in terms of water absorption ratio and whiteness. Sixty percent pearling rate in Yonezawa showed a higher absorption ratio and cooking whiteness than non-waxy Baekdong and Yeongsanbori. Gelatinization temperature was lower but maximum viscosity was higher in waxy than non-waxy barley.

• Korean Journal of Environmental Agriculture
• /
• v.26 no.3
• /
• pp.223-227
• /
• 2007

This study was carried out to establish the reasonable level of nitrogen (N) fertilization based on soil nitrate nitrogen $(NO_3-N)$ content for cucumber (Cucumis sativus L.) under plastic film house. Cucumber plants were cultivated with standard and free N fertilization in eight soils which had various amount of $NO_3-N$ ranging from 67 to 343 mg/kg. The yield of cucumber was in the range of 1006 to 2369 g/plant depending on the nitrogen supplying capability of soils. The amount of $NO_3-N$ in the soil was negatively correlated with agronomic efficiency (AE) and N use efficiency (NUE). The critical level of soil $NO_3-N$ content for cucumber in N free fertilization was found to be about 260 mg/kg in Cate-Nelson analysis of variance between soil $NO_3-N$ and AE or NUE. Also the same critical soil $NO_3-N$ content was found in the yield and amount of N uptake of cucumber under N free fertilization. A standard N fertilization was required when soil $NO_3-N$ content was below 70 mg/kg. The optimal application rate of N fertilizer for cucumber in the soils containing $NO_3-N$ between 260-70 mg/kg could be recommended by the equation Y=-1.032X+269.2 (Y: N fertilization rate, kg/ha; X : soil $NO_3-N$ content mg/kg).

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.2 no.1
• /
• pp.136-143
• /
• 2006

In this study, recently it is urgently required that demolition waste concrete has to be recycled on the construction because urban development is accelerated and redevelopment project is rapidly expanded, production quantity of construction and demolition waste concrete is being increased. As a results of drying shrinkage test under restrained and unrestrained condition, although workability and mechanical properites of concrete using HQRS were similar to that of concrete using natural sand, there were a great difference in deformation characteristic of dry shrinkage according to replacement ratio of HQRS. And, it makes sure that use of HQRS instead of partial nature sand was effective because drying shrinkage of concrete using 30 volume percentage of HQRS was smaller than that using only natural sand. Therefore, it is the objective of this study to provide the fundamental data about the re-application as an analysis of the drying shrinkage characteristics of concrete using HQRS and it is able to creta a high value-added by using HQRS.

• Korean Journal of Soil Science and Fertilizer
• /
• v.39 no.5
• /
• pp.298-302
• /
• 2006

This study was carried out to establish low-input fertilization and seeding technique using the simultaneous with seeding and fertilizer application machine and band spotty applicator which were manufactured for experiment during cultivation of mulching for peanut(Arachis hypogaea L.). The labor hour for seeding by simultaneous with seeding and fertilizing machine was appeared over 90% reduction effect compared with control plot($17.3hr\;10a^{-1}$). In band spotty fertilization plots, the emergence date was delayed about 4 days and the seedling stand rate was decreased 11~18% compared with control plot(man power). The content of total nitrogen of soil after experiment was increased while the contents of organic matter, available phosphate and exchangeable potassium were decreased than before experiment. The content of nitrogen forming nitrate was increased in band spotty fertilization(BSF) plots by increasing the amount of applied fertilizer from early growth stage till the middle growth stage. Growth rate was increased in band spotty fertilization plots and the absorbed amount of phosphate and potassium for peanut were increased in 70% band spotty fertilization plot compared with control plot. Yield of peanut was increased 70% in band spotty fertilization plot due to high pod kernel ratio and ripened pod rate compared with control plot($3,150kg\;ha^{-1}$). It was found that 70% band spotty fertilization was more effective as fertilization method to reduce both environmental pollution and chemical nitrogen fertilizer in plastic film mulching cultivation of peanut.