• Korean Journal of Soil Science and Fertilizer
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• v.27 no.1
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• pp.40-47
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• 1994

The objective of this research was to examine the effect of ammonium thiosulfate(ATS) on urease activity and on biological and chemical properties of flooded paddy soil especially having high organic matter content by comparing with the effect of sodium thiosulfate(STS). The results obtained are summarized as follows. 1. The hydrolysis of urea was inhibited at 3 and 5 days after treatment of thiosulfate(ATS and STS) +glucose and thiosulfate only, respectively. The inhibitory effect of ATS on urea hydrolysis was slightly lower than that of STS in glusoce-added soils, but when the glucose was not added, the effects of ATS and STS were not different significantly. 2. The soil pH and Eh was lowered by 0.3~0.5 units and 30~120 mV, respectively, when incubated flooded soil with ATS and glucose at $25^{\circ}C$. 3. Soil respiration rate in/flooded soil was increased by 10~70% with the treatment of ATS during the 20 day experimental period. 4. The contents of acetic and butyric acid in thiosulfate treatment soil was below $10{\mu}g/g$, which was lower than that($220.3{\mu}g/g$) of critical growth inhibition of rice.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2005.12a
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• pp.117-117
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• 2005

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.1
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• pp.49-53
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• 1979

Effects of temperature and light intensity on photosynthesis, respiration and chlorophyll content of ginseng (Panax ginseng C. A. Meyer) were as follow. 1. Optimum light intensity for apparent photosynthesis at $25^{\circ}C$ was 25Klux($1.35mgCO_2/dm^2{\cdot}hr$) for two years old ginseng grown in pot and 30Klux($1.94mgCO_2/dm^2{\cdot}hr$) for the six years old palmate cut leaves. Optimum temperature at 25Klux was $15^{\circ}C$ ($1.40mgCO_2$) for the 2 years old and 20 to $22^{\circ}C$ ($2.03mgCO_2$) for the 6 years old. 2. Dark respiration increased almost linearly with the increase of air temperature till $25^{\circ}C$ (2.6times between $16^{\circ}C$ to $25^{\circ}C$ for the 6 years old and 1.8 times between $15^{\circ}C$ to $25^{\circ}C$ for the 2 years old). Dark respiration was 11.1 % of net photosynthesis at $16^{\circ}C$, 17.8% at $25^{\circ}C$ for the 6 years old and 40% at $15^{\circ}C$, 64.7% at $25^{\circ}C$ for 2 years old. 3. Stomata appeared only in abaxial surface (lower epidermis) and stomatal frequency was $37per\;mm^2$. 4. Above results together with other informations quoted here strongly suggest that air temperature is much better criteria than light intensity for the improvement of shading roof material and shading construction. That is to promise maximum light intensity unless air temperature is above $25^{\circ}C$.

• The Korean Journal of Ecology
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• v.27 no.4
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• pp.245-256
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• 2004

The simple biosphere model 2 (SiB2), which is one of the land surface models, simulates the exchange of momentum, energy and mass such as water vapor and carbon dioxide between atmosphere and biosphere, and includes the biochemical sub-model for representation of stomatal conductance and photosynthetical activities. Throughout the SiB2 simulation, the significant information not only to understand of water and carbon budget but also to make an analysis of interaction such as feed-back and-forward between environment and vegetation is given. Using revised SiB2-Paddy, one sample study which is the evaluation of the runoff in Chaophraya river basin according to land use/cover change is presented in this review. Hence, SiB2 is available in order to ecological studied, if revised SiB2 for realistic simulation about soil respiration, computing leaf area index, vegetation competition and soil moisture is improved.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.2
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• pp.179-182
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• 1983

A survey on the physiological disorder of green pepper plant in the on-farm vinyl house where the by-product lime of $CaC_2$ applied and a pot experiment were carried out simultaneous to find out the causes. The results are as follows: 1. The pepper plants grown under the application of by-product lime were characterized with the dark brown spots on the leaves and the hindered rooting. Finally the leaves wilted and fell down. 2. Respiration of pepper plant grown in field where tile by-product lime of calcium car-bide applied decreased. 3. Acethylene gas was considerably detected from by-product lime and from the soil where the by-product was used. The severity of physiological disorder increased as the amount of the gas detected.

• Korean Journal of Medicinal Crop Science
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• v.25 no.6
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• pp.397-403
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• 2017

Background: This study was aimed at evaluating the growth, yield, and carbohydrate content in the whole Allium hookeri plant with shading treatment in hot summer. Methods and Results: Different shading rate, including 0 (control), 35 or 55%, was employed from the June $21^{st}$ to August $31^{st}$. Daily average air and soil temperature, which were approximately $2.5^{\circ}C$ and $3.8^{\circ}C$ lower, respectively, were observed with both 35% and 55% treatments in July and August, with no significant difference in daily maximum air temperature. Dry weights were high, approximately 40% and 48% for the shoot and 20% and 12% for the root, with the 35% and 55% treatments, respectively, 8 weeks after shading. Division number was increased by 13% and 19.8% with the 35% and 55% treatments, respectively. The mortality rates of 150 plants were 9.1%, 4.0%, and 1.3% with the 0 (control), 35% and 55% treatments, respectively. At 4 weeks after shading, the highest and lowest sucrose levels in both shoot and root were observed with the 35% and 55% treatments, respectively. At 8 weeks after shading, there was no significant difference in the sucrose content in the shoot among the treatments. Conclusions: The highest plant growth rate and yield with the 55% treatment may be related with the decrease in both air and soil temperatures, resulting in reducted leaf respiration and thus compensate net photosynthesis.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.6
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• pp.408-414
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• 2008

Importance of climate change and its impact on agriculture and environment has increased with the rise Green House Gases (GHGs) concentration in the atmosphere. To slow down the speed of climate change many efforts have been applied in industrial sectors to reduce GHGs emission and to enhance carbon storage. In agricultural sector, many researches have been performed on GHGs emission reduction, but few on the role of carbon sink. In this study, we investigated carbon balance and soil carbon storage in agricultural field in the barley-red pepper and barley-soybean cropping system. With the system for automatic measuring of carbon dioxide, net ecosystem production(NEP) was estimated to be $6.3ton\;CO_2\;ha-1$ for N-P-K chemical fertilizer treatment plot and $10.6ton\;CO_2\;ha^{-1}$ for N-P-K chemical fertilizer with swine manure treatment plot in the barley-soybean rotation cropping. In the barley-red pepper rotation cropping, it was $12.0ton\;CO_2\;ha^{-1}$ for N-P-K chemical fertilizer treatment plot and $13.2ton\;CO_2\;ha^{-1}$ for N-P-K chemical fertilizer with swine manure treatment plot. Soil carbon storage rate was estimated to be $0.7ton\;C\;ha^{-1}$ for the barley-soybean cropping system and $0.5ton\;C\;ha^{-1}$ for barley-pepper cropping system. In appeared that agricultural lands may contribute to the greenhouse effect as a potential carbon sink preserving carbon into soil.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.3
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• pp.115-127
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• 2018

This study was attempted to find out the value of cultural assets through the clear diagnosis and prescription of the dead and weakness factors of the Population of Retusa Fringe Trees in Pyeongji-ri, Jinan(Natural Monument No. 214), The results are as follows. First, Since the designation of 13 natural monuments in 1968, since 1973, many years have passed since then. In particular, despite the removal of some of the buried soil during the maintenance process, such as retreating from the fence of the primary school after 2010, Second, The first and third surviving tree of the designated trees also have many branches that are dead, the leaves are dull, and the amount of leaves is small. vitality of tree is 'extremely bad', and the first branch has already been faded by a large number of branches, and the amount of leaves is considerably low this year, so that only two flowers are bloomed. The second is also in a 'bad'state, with small leaves, low leaf density, and deformed water. The largest number 1 in the world is added to the concern that the s coverd oil is assumed to be paddy soils. Third, It is found that the composition ratio of silt is high because it is known as '[silty loam(SiL)]'. In addition, the pH of the northern soil at pH 1 was 6.6, which was significantly different from that of the other soil. In addition, the organic matter content was higher than the appropriate range, which is considered to reflect the result of continuous application for protection management. Fourth, It is considered that the root cause of failure and growth of Jinan pyeongji-ri Population of Retusa Fringe Trees group is chronic syndrome of serious menstrual deterioration due to covered soil. This can also be attributed to the newly planted succession and to some of the deaths. Fifthly, It is urgent to gradually remove the subsoil part, which is estimated to be the cause of the initial damage. Above all, it is almost impossible to remove the coverd soil after grasping the details of the soil, such as clayey soil, which is buried in the rootstock. After removal of the coverd soil, a pestle is installed to improve the respiration of the roots and the ground with Masato. And the dead 4th dead wood and the 5th and 6th dead wood are the best, and the lower layer vegetation is mown. The viable neck should be removed from the upper surface, and the bark defect should undergo surgery and induce the development of blindness by vestibule below the growth point. Sixth, The underground roots should be identified to prepare a method to improve the decompression of the root and the respiration of the soil. It is induced by the shortening of rotten roots by tracing the first half of the rootstock to induce the generation of new roots. Seventh, We try mulching to suppress weed occurrence, trampling pressure, and soil moisturizing effect. In addition, consideration should be given to the fertilization of the foliar fertilizer, the injection of the nutrients, and the soil management of the inorganic fertilizer for the continuous nutrition supply. Future monitoring and forecasting plans should be developed to check for changes continuously.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.1
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• pp.19-26
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• 2009

The standardization of eddy-covariance data processing is essential for the analysis and synthesis of vast amount of data being accumulated through continuous observations in various flux measurement networks. End users eventually benefit from the open and transparent standardization protocol by clear understanding of final products such as evapotranspiration and gross primary productivity. In this paper, we briefly introduced KoFlux efforts to standardize data processing methodologies and then estimated uncertainties of surface fluxes due to different processing methods. Based on our scrutiny of the data observed at Gwangneung KoFlux site, net ecosystem exchange and ecosystem respiration were sensitive to the selection of different processing methods. Gross primary production, however, was consistent within errors due to cancellation of the differences in NEE and Re, emphasizing that independent observation of ecosystem respiration is required for accurate estimates of carbon exchange. Nocturnal soil evaporation was small and thus the annually integrated evapotranspiration was not sensitive to the selection of different data processing methods. The implementation of such standardized data processing protocol to AsiaFlux will enable the establishment of consistent database for validation of models of carbon cycle, dynamic vegetation, and land-atmosphere interaction at regional scale.

• Korean Journal of Environmental Biology
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• v.34 no.4
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• pp.257-263
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• 2016

Objective of this study was to evaluate the carbon budget on 40 years old pear orchard at Naju. For carbon budget assessment, we measured the soil respiration, net ecosystem productivity of herbs, pear biomass and net ecosystem exchange. In 2015, pear orchard released about $25.6ton\;CO_2\;ha^{-1}$ by soil respiration. And $27.9ton\;CO_2\;ha^{-1}$ was sequestrated by biomass growth. Also about $12.6ton\;CO_2\;ha^{-1}$ was stored at pruning branches and about $5.2ton\;CO_2\;ha^{-1}$ for photosynthesis of herbs. As a result, 25.6 ton of $CO_2$ per ha is annually released to atmosphere. At the same time about 45.7 ton of $CO_2$ was sequestrated from atmosphere. When it sum up the amount of $CO_2$ release and sequestration, approximately $20.1ton\;CO_2\;ha^{-1}$ was sequestrated by pear orchard in 2015, and it showed no significant differences with net ecosystem exchanges ($17.8ton\;CO_2\;ha^{-1}\;yr^{-1}$) by eddy covariance method with the same period. Continuous research using various techniques will help the understanding of $CO_2$ dynamics in agroecosystem and it can be able to present a new methodology for assessment of carbon budget in woody crop field. Futhermore, it is expected that the this study can be used as the basic data to be recognized as a carbon sink.