• Applied Biological Chemistry
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• v.44 no.2
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• pp.92-96
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• 2001

Soil physical-chemical properties and phosphorous adsorption characteristics were investigated to obtain the informations of the appropriate fertilization and soil management in Baicheng region, China, where agricultural circumstances at present forces to consider the use of land for crop production. Soils were collected from one uncultivated and three cultivated lands on August 1993. Soil $_PH$ was very higher in uncultivated land than in cultivated land, their values were 10.2 and 7.4, respectively. Regardless of cultivation, soil organic matter contents were below 2%, and concentrations of available soil phosphorus expressed as Bray 1 P and Olson P were less than 10 mg P $kg^{-1}$, however, cation exchange capacity was higher than 20 cmol(+) $kg^{-1}$. For uncultivated soil, the values of exchangeable sodium percent and calcium saturation percent were higher than 100%. The major cation of soil saturation paste extracts was Na regardless of land use type. Based on electrical conductivity and sodium adsorption ratio of saturation paste extracts, uncultivated soil was classified as saline-sodic soil and cultivated soil was classified as sodic or normal soil. The maximum adsorption capacity of phosphorus calculated by Langmuir isotherm ranged from 406 to 521 mg P ,$kg^{-1}$. The constraints of soils in Baicheng regions for agricultural cops werw high salt concentration, unfavorable soil chemical composition such as low concentration of available phosphorous, and poor drainage due to soil dispersion by high Na concentration. Therefore, the soil in Baicheng region, need the application of phosphorus fertilizer to increase the soil fertility and the proper soil management to improve the soil physical property especially permeability and soil structure.

• The Korean Journal of Pesticide Science
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• v.12 no.1
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• pp.24-33
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• 2008

In this study, the mobility of seven pesticides from soil in different slopes was investigated by simulated rainfall under field conditions. Simulated rainfall subjected to $22\;mm\;hr^{-1}$ was treated using rainfall simulator after 12 hr of pesticide treatment. Amounts of the pesticides were measured in run-off water samples. The soil samples collected before and after rainfall from upper, middle and lower parts and three different depths of sloped-plot were also analyzed. At result, the order of the amount of pesticide residues was $0{\sim}15$ > $15{\sim}30$ > $30{\sim}45\;cm$ of soil depth and no pattern was shown in upper, middle and lower, and different slopes in soil samples. all pesticides from the run-off water samples collected from soils were detected maximum 96% within 60 minutes after first collection except carbendazim and cypermethrin which have the lowest water solubilities. These results revealed that mobility of pesticides can be dependant mainly on soil textures and physicochemical properties of pesticides. Therefore, it can be suggested that selection of pesticides should be considered for properties of pesticide in the alpine and sloped-land.

• Journal of Ginseng Research
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• v.25 no.1
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• pp.53-58
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• 2001

To clarify a significant difference between red-colored phenomena (RCP) and microbes isolated from rhizosphere soil of healthy ginseng (HES) and red-colored ginseng (RCS), we have examined growth and cellulase activities of the microbes according to pH variation and iron status. The soil microbes could not grow at pH 3.0 on the YEB medium. The growth of bacterium isolated from RCG at pH from 5.0 to 9.0 showed small differences and the growth of bacterium HES was lower than that of others. The growth of bacteria from RCS and surface soil (SUS) at pH 5.0 were also lower than that of pH 7.0 and pH 9.0. However, the bacteria isolated from red-colored ginseng (RCG) and RCS are able to grow on the medium contained 2 mM Fe$\^$3+/ at pH 3.0. Furthermore, the growth of bacterium from RCG increased about two times in the medium contained iron at pH 7.0 compared with minus iron. The cellulase activity of isolated bacteria increased two times in the medium contained 2 mM Fe$\^$3+/ compared with minus iron. The activity of extra-cellular cellulase was higher by one hundred times than that of intracellular level. The cellulase activity of the bacterium from RCS at pH 5.0 was higher by two times than that of pH 7.0. Especially, intracellular activity of the bacterium from RCS on the medium contained 2mM Fe$\^$3+/ increased about six to seven times compared with control (minus iron). Also, extra-cellular activity increased about eleven to twelve times compared with control. These results indicate that the soil microbes seem to be related iron redoxidation by proton extrusion and with cell wall digestion by secreted cellulase.

• Korean Journal of Weed Science
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• v.17 no.1
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• pp.10-23
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• 1997

This study was carried out to determine distribution and tuberization characteristics of tubers of water chestnut(Eleocharis Kuroguwai Ohwi) which is a dominant weed species and diffult to control during 1993 to 1994. By early planting of E. kuroguwai tubers, more and heavier tubers were developed, but the tubers were tended to distribute at the upper soils. Large proportion of tubers was remained at the upper 0 to 10cm soil layer and a few tubers were formed below 20cm. Tubers developed earlier tended to be at deeper layer, while later developed tubers were at upper layers. Tuber weight was increased from the surface to 20cm soil depths, but that formed below 20cm was almost same. No tillage resulted in more tuber formation which were distributed at upper soil layers when compared to conventional tillage. Cool water irrigation pumped from ground water resulted in less tuberization but smaller tubers when compared to control. Shading with color cellophan films resulted in smaller tuber formation with lower in sprouting percentage. Among the films tested, the most significant effect was obtained with green color.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.3
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• pp.175-184
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• 2002

Soil chemical parameters of peach orchards and the concentration of nutrients in peach leaves were investigated. Results of soil analysis showed that pH value and content of exchangeable calcium was quite low, required to adjust soil acidity in many investigated soils. Nitrogen and phosphorous contents in leaves were founded to be excessive comparing to RDA's optimal levels(N $29.3{\sim}35.9g\;kg^{-1}$, P $1.7{\sim}2.2g\;kg^{-1}$), while calcium contents were lower than optimal levels($11.2{\sim}21.0g\;kg^{-1}$) in many sites and Potassium content was higher in peach cultivars than nectarine cultivars. Correlation analysis revealed that organic matter contents in subsoils and exchangeable calcium content in soils(top and subsoil) were increased with cultivation year, but available phosphate contents in subsoils were decreased. Organic matter and exchangeable magnesium contents in top soils were positively correlated with potassium and magnesium contents in leaves, whereas were negatively correlated with calcium contents in leaves, impling antagonistic absorption of calcium against potassium and magnesium. The findings indicated that most of soils ought to managed to adjust soil acidity and application amount of nitrogen, phosphorous fertilizer and compost should be controlled properly.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.1
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• pp.28-34
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• 1991

This study was carried out to investigate the salt movement in upland soils in reclaimed region (Kye-Hwa Do). The results obtained were summarized as follows : 1. The cation content in ground water increased during time course. but in the case of land-surface water the content was variable, and $K^+$ was lower than that of $Na^+$ and $M^{+2}$. At the L. S. P(Low salinity plot) under rainproof condition, the salinity was directly proportional to soil water content, but at the H. S. P (High salinity plot) the tendency was no reversed. 3. In condition of rainproof, the amount of available phosphorous was higher at the H. S. P than at the L. S. P. 4. Positive correlation was obtained between the soil water content and available phosphorous content at the rainfall plot, but there was no significance at the surface soil of the rainproof plot. 5. SAR (Sodium adsorption ratio) and anion ($Cl^-$, $SO_4{^{2-}}$) contents in soil were repressed in the order of black vinyl>white vinyl>rice straw>control.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.3
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• pp.225-232
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• 1998

In order to monitor the degree of heavy metal distribution in upland cultivations in Korea, both the cultivated soils and crops were collected from the 854 and 140 sites, respectively. The contents of cadmium (Cd), copper(Cu), lead(Pb), and zinc(Zn) in each sample were measured by Inductively Coupled Plasma(ICP) technique after 1N-HCl extraction. The content of Arsenic(As) was also measured with the same technique after 1N-HCl extraction. The average contents of heavy metal in surface soils(0~15 cm depth) were $0.135mg\;kg^{-1}$ for Cd, $2.77mg\;kg^{-1}$ for Cu, $3.47mg\;kg^{-1}$ for Pb, $10.7mg\;kg^{-1}$ for Zn, and $0.57mg\;kg^{-1}$ for As. Heavy metal contents of soil were similar to those values measured for upland soils in 1989, lower than soils under plastic film house in 1996. However, these contents were lower than "Countermeasure values for soil contamination"(Cd: 4, Cu: 125, Pb: 300, and As: $15mg\;kg^{-1}$ in soil) describled in Soil Environmental Conservation Act in Korea(1996). The contents of heavy metal in fresh vegetable, and root and tuber crops ranged $0.005{\sim}0.019mg\;kg^{-1}$ for Cd, $0.20{\sim}1.03mg\;kg^{-1}$ for Cu, $0.042{\sim}0.104mg\;kg^{-1}$ for Pb, and $2.0{\sim}4.0mg\;kg^{-1}$ for Zn, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.297-302
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• 1996

The effect of application rate of pig or chicken manure on the seasonal change of tomato(Minicarol) rhizosphere microflora was investigated by field experiment were surface soil(16cm) mixed with manures 1 weeks before transplanting. 1. Rhizobacteria population of control plot decreased 5 weeks after transplanting(WAT) than 1 WAT and 1.5~2 times higher colony counting was found in DNB(Diluted nutrient broth medium) than NB(Nutrient broth medium) at 15 WAT. 2. Rhizobacteria population at 1 WAT inereased in NB medium with the application rate of both manures but decreased in DNB with chicken manure. Colony counting in NB of 60 and 120 mg/ha treatment was 100 times higher than that of the control. However, rhizobacteria in DNB at 15 WAT(harvest stage) was much higher than that of NB. 3. Application rate did not affect fungi population 1 WAT in pig manure but decresed in chicken manure. At 15 WAT fungi population was 2 times higher than 1 WAT with chieken manure and highest in 30 mg/ha but with pig manure decreased with rate than the control. 4. Actinomycetes population at 1WAT was not different among pig manure rates and decreased with chicken manure than control. At 15 WAT population increased in all manure rates. especially in 10 mg/ha pig manure and 30 mg/ha chicken manure 4 times that 1 WAT.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.779-786
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• 2012

Many farmers have been seeking alternatives to chemical fertilizer for successful organic fruit production. This experiment was carried out to investigate the replaceability of chemical fertilizer by cover crop and slurry composting biofiltration (SCB) liquid manure (LM) application in pear orchard. Three treatments were contained in this experiment; cover crop only and cover crop + LM treatment, and control (chemical fertilizer application). Dry weight and mineral contents of gramineous cover crops were significantly increased in LM-combined treatments than that of leguminous species. Bulk density of soil was decreased in rye + LM and hairy vetch + LM treatments, compared with each cover crop treatment. Soil pH was lowest in fertilizer treatment and soil nitrate content became similar between treatments after rainy season. Available soil phosphate was lower in cover crop and cover crop + LM treatmemts than control, but exchangeable Mg was higher. The mineral content and net assimilation rate of leaves showed no difference between the treatments. As a result, it is suggested that the application of SCB liquid manure in pear orchard managed by cover crops is desirable to maintain the productivity by improving soil physical properties and potential nutrient recovery.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.145-151
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• 2009

This study was conducted to develop rational soil management and enhance the productivity of lands converted from paddy soils. Specifically, the changes in the soil physical properties brought about by the change in land usage from paddy soil were evaluated. This was carried out from 1999 to 2001 at 50 site in large-scale converted paddy fields of Kimcheon, Youngcheon, Gyeongsan and Milyang in the Youngnam region, categorized according to soil texture and drainage class. The ridge height of converted paddy soils was higher in coarse-textured and poorly-drained soils than in fine-textured and well-drained soils. The gray color of the surface soil was of lesser degree in converted soils than paddy soils and more notable in welldrained soils. The porosity ratio and the formation of aggregate structure were higher, and the appearance of soil mottling was deeper in converted paddy fields than in paddy soils. The glaying layer "g" of surface soil degraded with time. The porosity and amount of water stable aggregate was found to increase with time after conversion. The penetration resistance of the converted paddy soil was lower and deeper with time after conversion. The soil aeration of the converted paddy soil was lower in sandy loam than in loamy soil. Furthermore, soil aeration was influenced by ridge height and drainage class in poorly-drained soils.