• Korean Journal of Soil Science and Fertilizer
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• v.8 no.2
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• pp.53-60
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• 1975

Vegetables are often cultivated continuously year round in a vinyl house with heavy application of fertlilizers, which leads to accumulation of salts in the soil. A field experiment was conducted to investigate the effect of watering on salt eluviation from the soil, and on the yield of tomatoes in the vinyl house. The results were summarized as the followings: The salt eluviation increased with the amount of water applied. The efficiency of the salt eluviation was greater for the silty clay loam soil than the sandy loam soil. With a given amount of water, the efficiency increased with frequency of watering. The yield of tomatoes was increased by watering. However, the yield was not necessarily correlated to the amount of salt leached. Increase in yield of tomatoes by watering was in order of the treatment, 100mm (50-50), 150mm (50-50-50 or 100-50), and 200mm (100-100) of water for both soils. Relationship between the yield of tomatoes and electrical conductibity of the soil (1 : 5 extract) was described by the following regression equation : $Y=1,739.0+437.5X-290.5X^2$ $(R=0.632^{**})$ for sandy loam soil, and $Y=1.542.2+454.1X-275.0X^2$ $(R=0.622^{**})$ for silty clay loam soil. The yield of tomatoes in salt accumulated soil was inversely correlated to extractable sodium and potassium, and to the ratio of extractable sodium to calcium (Na/Ca), while the yield was not correlated to extractable calcium and magnesium.

• Korean Journal of Environmental Agriculture
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• v.14 no.1
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• pp.28-44
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• 1995

Residue level of myclobutanil[2-p-chlorophenyl-2-(1H-1,2,4-trizol-l-yl-methyl) hexane nitril] and number of soil microorganism were investigated at different environmental conditions such as the sterile and the non-sterile soils, moisture content, pH, temperature, application rate, and soil types under laboratory and field to study the effect of those factors on degradation characteristics of this fungicide and change of microflora in soil. Decomposition rate of myclobutanil was 3.9 times faster in the non-sterile soil than in the sterile soil, 1.6 times in the field than in the laboratory, 1.4 times in the concentration of 10ppm than in that of 20ppm, and 1.2 times in the clay loam soil than in the silty loam soil. Degradation rate of myclobutanil was the fastest at pH 9.0 among the tested pHs and the latest at pH 5.5. Degradation rate of myclobutanil was in order of $27^{\circ}C$ > $37^{\circ}C$ > $17^{\circ}C$. Otherwise, the effect of soil water content on myclobutanil degradation was found not clear. Number of microorganism in the non-sterile soil was remarkedly more than that in the sterile soil. Numbers of microbes were not significantly different between treatment plot and non-treatment plot of myclobutanil at the different conditions of soil moisture content, pH, temperature and soil type. Numbers of fungi and total microbes were more in the treatment than in the non-treatment of myclobutanil at field test but the same trends were not found at laboratory test. Within non-treatment of myclobutanil, numbers of microbes were not significantly different under the various condition of pH, application rate, and soil type in laboratory and upland field. The number of bacteria were more in 60% moisture content of water holding capacity than in 40% and the number of fungi were more in $17^{\circ}C$ of soil temperature than in $37^{\circ}C$. Within the application plot of myclobutanil, numbers of microbes were not significantly different at various pH in laboratory and upland field. The number of bacteria and total microbes were more in 80% moisture content of water holding capacity than in 40% and 60% and actinomycetes were more at $27^{\circ}C$ in the clay loam soil than at $17^{\circ}C$ in the silty loam soil.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.664-670
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• 2012

Experiments were conducted to find out the landscape effects and green manure production at the same time in farmland. Cornflower was grown in different soil texture with sand, sandy loam, loam, clay loam, and was sowing with autumn and spring respectively. The overwintering rate of cornflower was at 58.7% in average, and the treatment at sand soil showed 62.1% that was highest among other soils, which cornflower is possible to winter landscape crop. After flowering of cornflower, the contents of total nitrogen (T-N) and total carbon (T-C) in plant were 15.0 and $409.2g\;kg^{-1}$, respectively, and the carbon-nitrogen ratio (C/N) was 28.6. The yield of cornflower biomass, which will be returned to soil as green manure, recorded $1,210{\sim}3,920kg\;ha^{-1}$ at the spring seeding higher than the autumn seeding as $1,540{\sim}3,170kg\;ha^{-1}$, and the biomass treated by soil texture were showed that the treatments at the clay loam had been the largest yields both spring and autumn seeding among at other treatment of soil. The heights of cornflower regardless of soil treatments were 52.8 to 73.6 cm at the autumn seeding and 35.5 to 79.2 cm at the spring seeding although it was more significant variation at the soil textures than the seeding periods. The flowering periods of cornflower ranged from $17^{th}$ to $20^{th}$ in May at the autumn seeding and from $19^{th}$ to $20^{th}$ in June at the spring seeding, which was faster 30 days approximately at the autumn seeding than the spring seeding. In a view of the cornflower application as green manure after flowering, the autumn seeding, when considered to combine with following crops, was more suitable and various than the spring seeding, even though the yield at spring seeding was higher than one at autumn seeding.

• Korean journal of applied entomology
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• v.24 no.1 s.62
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• pp.39-44
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• 1985

This study was undertaken to select a suitable Korean tissue paper for Baermann funnel method. Ten kinds of five manufacturers were evaluated as to nematode extraction efficiency in Baermann funnel. 'Crown Hankie'(Korea Special Paper Co., Ltd.) had suitable properties in nematode permeability and strength regardless of three soil types, loamy sand, sandy loam and clay loam. The number of nematodes extracted using 'Crown Hankie' 4 ply was 198, while that of 'Cottonwool Nematode Filter' was 227. Un-perfumed tissue papers showed higher nematode extraction efficiencies than perfumed tissue papers by 53 and 23% in 'Kleenex New Softness' and 'Monaliza Finely Soft Tissue', respectively. Among the nematode extraction efficiencies by temperatures, $15^{\circ},\;25^{\circ}\;and\;35^{\circ}C$, it was highest at $35^{\circ}C$. In experiment of evaluating nematode extraction using Baermann funnel at 12 hours interval to 92 hours, 35.3 and 40.3% of nematodes were extracted after 12 and 24 hours, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.5
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• pp.303-309
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• 2008

The physico-chemical properties of the rainfall interception culture (85 sites) and the open field culture soils (85 sites) in the area of Gochang-gun, Jeollabuk-do were surveyed. Soil textural distribution of the rainfall interception culture and the open field culture soils was 74% and 64% for silt loam, 16% and 35% for loam, and 10% and 1% for clay, respectively. The percentage of aggregate rates was higher in the open field culture soils (60.06%) than rainfall interception culture soils (55.84%). Electrical conductivity, exchangeable cations, and anions in the rainfall interception culture soils were higher than those in open field soils. Specially, accumulated amount of anion in rainfall interception culture soils was remarkably higher 2~3 times than open field culture soils. The results from the analyses of rainfall interception culture soils suggested that the most critical problem is the salts accumulation caused by over-fertilization of chemical fertilizer and compost. Therefore, application rates of chemical fertilizer and compost should be controlled in order to conservation of soil and water for sustainable agriculture.

• Korean Journal of Medicinal Crop Science
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• v.9 no.2
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• pp.91-98
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• 2001

Scutellaria baicalensis G. was cultivated in plots of different soil textures which were sand loam(SL), loam(L) and clay loam(CL). Also three fertilizer conditions were used; non application (NA)treatment, rice straw manure(RSM) treatment and N-P-K, chemical fertilization(CF) treatment. The chemical-physical properties, such as organic matter, available phosphate, $K_2O$, CaO, clay contents and porosity ratio in CL plot with RSM application were the most proper in CL plot and RSM application for the culture of S. baicalensis plants. RSM had very high contents of total nitrogen, 2.25% and C/N ratios, 21.4. Thus the growth of shoot and root in loam plot with RSM treatment were greater compared to that of CL plot with NA treatment. Whereas, The highest baicalin, baicalein and wogonin contents in roots were found in CL plot with RSM treatment. There was significantly positive correlation between aerial and underground parts of plant, yield and contents of T-N, $K_2O$ but negatively correlated with the contents of baicalin, baicalein and wogonin in S. baicalensis roots.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.2
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• pp.135-144
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• 1995

Understanding on nutrient solute movement during the course of freezing and thawing was attempted through laboratory and field obsevations. Small sectioned tubes with 5cm inner diameter, 0.2cm thick and 1cm long were connected to 30cm long soil columns for laboratory study. The columns were filled with soil, and treated with 20mmol/kg $KNO_3$ for upper 5cm. The upper end was set in the freezing section, and the lower end was set in the refrigerating section of a refrigerator. Temperature was controlled at $-7({\pm}1)^{\circ}C$ and $1.5({\pm}1)^{\circ}C$, respectively. After top 5cm soil was frozen, the columns were sectioned, and analyzed for $NO_3^-$, $NH_4^+$ and $K^+$. For field study, the 20cm inner diameter and lm long soil columns were installed in Chuncheon and Daegwanryung, where the altitude was 74m and 840m, respectively. The soils used were silt loam and clay loam. The top 20cm soils were treated with 50mmol/kg as $KNO_3$. The soil columns were taken during winter freezing and after thawing. By laboratiry study, upward movement of $NO_3^-$ and $K^+$ during the course of freezing was confirmed. The upward movement of $K^+$ was, however, one fifth to one tenth of $NO_3^-$. The upward movement of inorganic nitrogen as well as laboratory during the course of freezing, but large amount of nitrogen was lost from the profile after thawing in early spring. Leached nitrogen from the upper 20cm to lower part was 17 to 24 percents. The maximum depth of leaching during the experiment was 50cm for all soils. The net loss of inorganic nitrogen from the whole profile ranged 8.7 to 39.5 percents. The net loss was greater in Daegwanryung where temperature was lower and snowfall was larger than Chuncheon, and the loss was greater from the silt loam soil than clay loam soil of which percolation rate was small. The results implied that reasons for nitrogen loss during the winter might include surface washing by snow melt as well as leaching and denitrification.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.2
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• pp.131-138
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• 1996

Soil crusting and hardening as a result of drying after rainfall were examined in relation to seedling emergence by employing five rice varieties (Italiconaverneco, Dadazo, and Galsaekggarakshare, Dongjinbyeo and Sumjinbyeo) and two barnyardgrass species (E. crus-gallj var. oryzjcola and E. crus-galli var. praticola). Sandy loam, loam, and silty loam soils were used. The artificial rainfall of 0, 20 and 40mm were applied after sowing and covering with 4cm soil. Air temperature and solar radiation averaged over 9 days after seeding was 31.3$^{\circ}C$ and 16.9MJ /m$^2$, respectively. Soil strength increased rapidly by drying after artificial rainfall, being greater in soils with greater amount of clay and artificial rainfall. Soil crust was formed on the surface with artificial rainfall in all soils tested. However, soil crust was exfoliated in silty loam and loam soil, and lifted as seedlings emerge. Seedling emergence of rice varieties was decreased by rainfall treatments. Sumjinbyeo and Dongjinbyeo showed much poorer seedling emergence especially in sandy loam soil than the other varieties. Poor seedling emergence of these varieties might have been caused by delayed seedling emergence which had made them expose to greater soil strength. Seedling emergence of barnyardgrasses showed no differences among soil textures and rainfall treatments, because they emerged rapidly before soil crusting and hardening were proceeded enough to hamper seedling emergence. Seedling emergence of Sumjinbyeo and Dongjinbyeo decreased with increasing soil strength averaged over 3 days to 5 days after seeding, being lowered to 80% at soil strength of 1.0kg/cm$^2$ and to 50% at 1.7kg/cm$^2$. Emergence speed of barnyardgrasses was faster than rice varieties, and E. crus-galli var. oryzjcola than E. crus-galli var. praticola. Italiconaverneco and Dadazo showed faster emergence in rice varieties. Galsaekggarakshare showed slower emergence speed than these two varieties with similar seedling emergence percentage. The greater and faster elongations of mesocotyl and incomplete leaf in rice, and of mesocotyl in barnyardgrass were the characteristics responsible for higher seedling emergence rate in the environment examined.

• Korean Journal of Soil Science and Fertilizer
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• v.3 no.1
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• pp.61-66
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• 1970

This study examined the morphology and physical and chemical characteristics of the Changpyeong series developed on gently sloping to rolling relief on dissected old paddiplains and terraces. This soil has dark brown silty clay loam A horizons, very thick dark red to red silty clay or clay Bt horizons, and C horizons of old alluvial materials frequently with strongly weathered round cobbles and pebbles. It is strongly acid with a low organic matter content, relatively low in cation exchange capacity, but with relatively high base-status based on amount of extractable cations. There is no obvious changes in particle size distribution with depth and textural B horizons probably have not been formed by podzolization but formed by mechanical movement of clay. This soil is classified as Typic Hapludalfs in USDA 7th approximation and Brunic Luvisols in FAO classification system.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.3
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• pp.104-109
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• 1981

The experiment was designed to measure splash erosion and to investigate the relationships between soil detachment, kinetic energy and C factor at various soils and crops under the natural rainfall, using the modified Ellison cup. The results obtained were as follows: 1. Splash erosion increased as the texture was coarser, reaching a maximum amount in loamy sand of 12.6ton/10a/year, 9.7ton for loam, 9.0ton for sandy loam, and 7.0ton for clay loam. 2. Splash erosion positively related to kinetic energy ($EI_{30}$) but negatively to K value. 3. A considerable relationship between splash erosion and kinetic energy was observed under coverage less than 50%; however, it decreased with increasing canopy resulting in no relation over 90% coverage. The amount of soil detachment by natural rainfall ranged from 10 to 15ton/10a at various cropping systems. 4. The particle size distribution of splashed soil was similar to that of original one and fine sand($250-100{\mu}$) marked the highest detachment and splash.