• Asian Journal of Turfgrass Science
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• v.5 no.1
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• pp.47-53
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• 1991

A laboratory experiment was conducted in order to learn the effect of a number of organic matters on the ammonification and nitrification of urea, and the reaction of soil, applied to a loamy upland soil poor in orgnic matter(<1.5%, without plants 1.The ammonification of urea was most pronounced in one week period immediatly after fertilizer and water treated, after which a rapid decrease of it was followed showing no accumulation at the end of 3rd week. Owing to the accumlation of ammonium, pHs of treated soils were read 7.0 to 7.3 from 6.8~6.9. 2.Nitrification was also progressed rapidly in the first one week period so that the accumulation of NO$_3$-N surpassed that of ammonia during this period. After the 1st week the accumulation of N0$_3$-N was continuously increased showing the maximum at the end of 4 weeks following a sharp decrease at the end of 5th weeks. The accumulation of NO$_3$-N dropped soil pH from 6.8-7.0 to 6. 0-6.2,but the decrease of NO-N at the end of 5th weeks brought up soil pH to 6.4-6.6. again. 3.Amino acid fermentation byproduct rich in salt, paticularly chloride, slowed down the ammonification and nitrification of urea. 4.The application of organic matter diminished the acidifying effect of chemical fertilizers. The diminishing effect of soluble humic acid and amion acid fermentation byproduct showed greater than that of solid organic matter in this experiment, which might be own to the application of a rather small amount of water soluble organic matters. Rice straw powder among solid organic matters appeared to be the least in the diminishing effect above. It may be reasoned that these soluble organic matters decomposes rapidly so as to affect Soil pH, but solid organic matters, particularly the rice straw powder, form acidic humus.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.2
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• pp.119-129
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• 1999

It may be said that ancient wild Chinese garden had been founded during Qin dynasty and completed through Han, Sui and Tang dynasties. At first used as hunting areas for kings, the ancient resort forests began to take forms of garden. They dug a pond in the garden and made a simulated mountains with the soil that came from the excavations for the pond and suc pavilions has Gyong, Ru, Gak etc. were built around the pond. The ponds were different in size from those in Korea, being of the lake-like size. they made three island in the pond, which were the islands of Taoist hermits with supernatural powers, called Bong-lae, Young-ju and Band-jang respectively. the traditional of making those islands began in the Qin era and were completed in the Han era, being descended to posterity as a traditional garden structure of 'three islands in one pond' garden style. Such style was brought to Korea and first appeared as Kung-Nam-Ji in Back-jae kingdom and then brought to Japan, becoming the tradition of constructing ponds from early Heian era. Those lake-like huge Chinese ponds constituted the core of ancient garden where various feasts took place. Such ponds were also placed at the center of the gardens and played the roles of feasting garden ponds. Through the above-mentioned studies of the ancient Chines garden, the origin of them and the influence of the ancient Chinese ponded garden upon those of Korea and Japan were investigated.

• Journal of the Korean Geographical Society
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• v.45 no.1
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• pp.95-118
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• 2010

This study aims to investigate the spatial distribution of major soil types in Korea, and to assess the ability to predict soil distribution using environmental variables. A classification tree method was used to assess soil predictability. While the great soil groups can give more intuitive understandings on their spatial distributions, its predictability using environmental factors is much lower than that of the great groups. The most important factor to determine the spatial distribution of major soil types is the geomorphological characteristic of Korea that shows distinctive morphological difference between mountains and plains. Spatial distribution of climatic variables and catenary soil sequence along slopes play additional roles in determining the distribution of soil types. The classification tree models resulted in 35-75% of prediction accuracy, depends on the combination of different environmental variables brought in the models. While geomorphological variables are the best predictors for the great groups, climatic variables perform better for the great soil groups.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.1
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• pp.17-23
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• 1981

The effects of potassium chloride and potassium sulphate on the volatilization of ammonia from acidic clayloam and tidal sandy clay loam soils applied with urea under flooded conditions were studied in a laboratory experiment. Results obtained were as follows; 1. The application of potassium to the acidic soil promoted the volatilization of ammonia through increasing soil pH. 2. The application of potassium to urea treated on the tidal soil which lead pH over 8.0 under flooded reduced conditions decreased the wet soil pH and reduced the volatilization of ammonia from the soil. These effects of potassium were more pronounced in the potassium sulphate treatment than in the potassium chloride. 3. More ammonia was volatilized from the acidic soil applied with potassium sulphate, however, the effects of potassium fertilizers applied to the high pH tidal soil seemed to be masked by high salt content of the soil. 4. Urea brought up soil pH significantly. Potassium sulphate was more effective than potassium chloride in raising pH of the acidic soil, though the reverse could be true in the tidal soil with high pH. The reduction of sulphate might be a major cause for the pH change.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.1
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• pp.27-36
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• 2006

Most of domestic multipurpose dams were basin area to be large, therefore, soil loss were occurred by downpour in the rainy season, They have caused to accumulate sediments on the river and dam reservoir that brought the decrease of storage volume and difficulties of the quality management of water. Until now, the measurement cycle of sediments surveying was long and it was designed to use surveying the degree of sediments, Thus there were many difficult things to secure accuracy. In this study, it was intended to analyze the origin position tracing of sediments and the movement route, for this purpose, aerial LiDAR technology was applied to precise sediments surveying. The amount and location of soil loss were evaluated by classified properties of soil, land-cover, and topographical conditions in detail. Therefore, the reliance could be maintained in analyzing the route of soil loss by extracting the flow within a watercourse and using the advanced accurate DEM.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.6
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• pp.492-499
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• 2009

Effect of drip irrigation on soil salinity control and growth of vegetable crops was studied in the three reclaimed lands of Korea in 2007. Drip irrigation was done one or two times per month for reduction of salt stress by using vinyl hose with tiny holes laid on ridge surface under black plastic film mulch during growing season of cabbage and chinese cabbage. It was observed that drip irrigation was generally effective to soil salinity control, but soil salinity variation of some place was not fully solved to lower down under level of free salt stress. It is also considered that high salinity of runoff water spilled out from cultivation ridge plays another key role for soil salinity management. Consequentially, this soil salinity variation might be one of factors brought low average yield and low commercial ratio of agricultural products. Relation between soil salinity and head growth of cabbage and chinese cabbage was well expressed as logarithmic function. Surface soil EC to reach at 50% of growth reduction to the heaviest head can be estimated was $6.1dS^{\circ}{\S}m^{-1}$ for cabbage and $5.7dS\;m^{-1}$ for chinese cabbage transplanted at optimum season.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.961-967
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• 2012

There have been many studies about efficiency of amendments for heavy metal stabilization through chemical assessment. The objective of this study was to evaluate the efficiency of several soil amendments (lime, agric-lime, dolomite, steel slag, fly ash and acid mine drainage sludge) on heavy metals stabilization through not only chemical but also biological assessments (phytotoxicity test) in abandoned mining area soil. In order to achieve the goal, we conducted preliminary screening experiment targeting 12 types of crop plants such as radish, young radish, chinese cabbage, winter grown cabbage, cabbage, bok choy, chicory, crown daisy, carrot, chives, spinach, and spring onion. The results of inhibition rates of early plant growth in metal-contaminated soil against non-contaminated soil and the correlations between inhibitions items showed that the bok choy was appropriate specie with respect to confirm the effect of several amendments. Several amendment treatments on contaminated soil brought about the changes in the root and shoot elongation of bok choy after 1 week. Agric-lime, dolomite and steel slag treatments showed the great efficiency of reducing on mobility of heavy metals using chemical assessment. But in contrary, these treatments resulted in the reduction of root and shoot elongation and only AMD sludge increased that of elongation, significantly. When considering both chemical and biological assessments, AMD sludge could be recommended the compatible amendment for target contaminated soil. In conclusion, biological assessment was also important aspect of decision of successful soil remediation.

• Korean Journal of Environmental Agriculture
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• v.29 no.3
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• pp.282-286
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• 2010

The present studies were carried out for three years from 2007 until 2009 to control nematode and to increase yield of cucumber by crashed-rape seed application at polyethylene film house. Crashed-rape seed has a lot of glucosinolate. Myrosinase decompose gulcosinolate into isothiocyanate and thiocyanate when crashedrape seed go to decay at soil. Those chemical compounds act on poison to nematode at soil. When the crashedrape seed treated at soil, an amount of thiocyanate at soil was risen up. Thiocyanate of plot treated with 200 and 400 kg crashed-rape seed per 10a was 30 and 40 mg/kg, respectively. Nematode(meloidogyne spp) population at soil was 13 to 17 nematodes per dried soil 300g. Yield of cucumber increased 6 to 15 percent to be compared with control. While, Nematode(meloidogyne spp) population of control plot were 463 nematodes per dried soil 300 g. This level was much higher than 150 nematodes which can be brought about injury to plant. Even if the more an amount of crashed-rape seed application, the higher yield of cucumber and control effect of nematode. Consider economical efficiency, 200 kg of crashed-rape seed per 10a was the most effective. Therefore, we suggest applying 200 kg of crashed-rape seed per 10a to control soil nematode when culture cucumber at plastic film house.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.1
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• pp.25-30
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• 1989

A field experiment was carried out to evaluate the effects of zeolite application and vinyl mulching on the changes in soil physico-chemical properties and yield of silage corn on the newly-reclaimed sloped land. Corn (Suweon 19) was cultivated under 4 application levels of zeolite, 0, 500, 1,000 and 1,500 kg/10a, with and without vinyl mulching, and various soil physico-chemical properties and corn growth were investigated. Soil physical properties, such as cation exchange capacity and water stable aggregates, were increased, but soil hardness was decreased by zeolite application. The porosity and temperature of soil were increased greatly by vinyl mulching. The differences between daily maximum and minimum soil temperature were large in beginning stages of crop growth, but those were decreased to $2^{\circ}C$ after mid-August. Zeolite application enhanced the plant growth and increased yields by 3-37% compare to control, also vinyl mulching brought to increase the corn yields by 17-23%. Water stable aggregates was correlated with soil hardness, and silage yields were highly correlated with porosity, air phase and water stable aggregates.

• Korean journal of applied entomology
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• v.15 no.4 s.29
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• pp.205-214
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• 1976

Effect of Butachlor(2-chloro-2, 6-diethyl N-(buthoxymethyl) acetanilide), Nitrofen(2,4-dichloro-4-nitrodiphenyl ether), Benthiocarb+Simetryne(s-(4-chlorobenzyl)-N, N-diethylthiocarbamate $7\%$+2-methylthio-4, 6-bis(ethylamino)-s-triazine $1.5\%)$, Propanil (3,4-dichloropropionanilide), and Perfluidone {1. 1. 1-trifluoro-N, N-(2-methyl-4-(phenylsulfonyl) Pheny1) methanesulfon amide} on urea hydrolysis and subsequent nitrification was investigated in a flooded soil incubated at $24\pm1^{\circ}C$ for 9 weeks. 1. Butachlor and Perfluidone at the rate of 1,440 and 1,200g, ai/10a, respectively, slightly inhibited the early stage of urea decomposition, and caused a slight decrease in the production of ammomium, which, however, was recovered readily. 2. Propanil at the rate of 2,800g, ai/10a imhibited the first stage of nitrification, and brought about a slight increase in the ammonium conentration and a decrease in the concentration of nitrite and nitrate. This inhibitive effect was a little more evident at higher concentration of applied nitrogen. The other herbicides caused no inhibition of urea decomposition and subsequent nitrification even at the highest rate of application. 3. pH and Eh of the soil were not significantly affected by the herbicides tested.