• Journal of Bio-Environment Control
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• v.13 no.3
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• pp.156-161
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• 2004

This study was conducted to investigate the effects of soil amendment with different characteristics on plant growth, fruit yield and quality of oriental melon for continuous cropping under protected cultivation. Humus layers in arable soil was disturbed because soil amendment from hillside to oriental melon field was continued to resolve problems for continuous cropping. Water potential and hardness of soil was decreased in sandy loam with lower clay contents compared with loam and silty clay. Leaf length and area, fresh and dry weight of plant at earlier growing stage were higher, but chlorophyll contents of leaves were dropped in sandy loam compared with silty clay soil. Fruit size and weight was higher in sandy loam, but soluble solid and color of fruit were increased in silty clay. Marketable and unmarketable yield and quantity of fermented fruit were the highest in sandy loam. Hardness and weight of fruit were decreased by longer storage period and soluble solids of fruit was peaked at 5 day after storage, but decreased by prolonged continued storage. Because of these results, soil characteristics of amendment to oriental melon field should be considered as an important factor for quality and yield of oriental melon.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.548-554
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• 2016

Optimal range of soil physical quality to enhance crop productivity or to improve environmental health is still in dispute for the upland soil. We hypothesized that the optimal range might be established by comparing soil physical parameters and their interactions inhibiting crop growth. The parameter identifying optimal range covered favorable conditions of aeration, permeability and root extension. To establish soil physical standard two experiments were conducted as follows; 1) investigating interactions of bulk density and aeration porosity in the laboratory test and 2) determining effects of soil compaction and deep & conventional tillage on physical properties and crop growth in the field test. The crops were Perilla frutescens, Zea mays L., Solanum tuberosum L. and Secale cereael. The saturated hydraulic conductivity, bulk density from the root depth, root growth and stem length were obtained. Higher bulk density showed lower aeration porosity and hydraulic conductivity, and finer texture had lower threshold bulk density at 10% aeration bulk density. Reduced crop growth by subsoil compaction was higher in silt clay loam compared to other textures. Loam soil had better physical improvement in deep rotary tillage plot. Combined with results of the present studies, the soil physical quality was possibly assessed by bulk density index. Threshold subsoil bulk density as the upper value were $1.55Mg\;m^{-3}$ in sandy loam, $1.50Mg\;m^{-3}$ in loam and $1.45Mg\;m^{-3}$ in silty clay loam for optimal soil physical quality in upland.

• Korean Journal of Medicinal Crop Science
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• v.15 no.1
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• pp.12-16
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• 2007

This study was carried out to investigate the cultivated soil properties, the growth and yield of Ostericum koreanum Kit. in the Bonghwa area. The results were as follows: In Bonghwa area, soil texture of upland soil were mostly sandy loam and loam. Sloped areas of $7\sim15%$ were plentiful than the other slopes, that of next was $15\sim30%$ slope. Sandy loam and loam soil were mostly 'well' in the drainage class, but loamy coarse sand and loamy sand soil were 'excessively well' drainage class. In the 'moderately well' drainage class, yield of Ostericum koreanum was 289kg/10a, and that of 'poorly' drainage class was low. The yield of loam soil texture was 284kg/10a. Soil organic matter, Potassium and EC were lower in 'poorly' drainage, but the other constituents were not definite tendency by different drainage classes.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.2
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• pp.65-71
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• 1994

This study was conducted to investigate the influence of treatment of fly ash on heavy metal contents in the arable soils. Rice was cultivated on the two types of paddy field(clay loam and sandy loam soil) with 0, 4, 8, 12t/10a of anthracite fly ash and bituminous coal fly ash, respectively. And soybean was cultivated on the same types of upland field with those of 0, 3, 6, 9t/10a, respectively. At the harvest time, the heavy metal contents in surface and subsoil were investigated. The results were summarized as follows : 1. Anthracite fly ash. 1) In the paddy field of clay loam, the contents of Cu and Zn in the surface soil and Cd and Ni in the subsoil were increased with the increase of the amount of fly ash applied, but the others didn't show that tendency. 2) In the paddy field of sandy loam, only the content of Fe was increased in the surface and subsoils. 3) In the case of upland soil, the concentration of Ni and Cr in the surface soil and Cd in the subsoil were increased in the clay loam soil, and those of Cr in the surface soil and Pb in the subsoil were increased in the sandy loam soil. 2. Bituminous coal fly ash 1) In the paddy field of clay loam, the contents of Cu and Zn in the subsoil were increased with increase of the amount of fly ash applied, but in the case of sandy loam, those of Pb and Ni in the surface soil were increased. 2) In the upland soil of clay loam, the concentration of Ni in the surface soil and Pb in the subsoil were increased. 3) In case of upland soil of sandy loam, the contents of Cr and Fe were increased in the surface and subsoil, respectively, but those of Cu and Mn were increased in the both of the surface and subsoil.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.309-315
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• 2009

Maintenance of adequate soil water content during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil water movement for precision irrigation would allow efficient supply of water to crops, thereby resulting in minimization of water drainage and contamination of ground water. This research reports on the characterization of spatial and temporal variations in water contents through three different textured soils, such as loam, sandy loam, and loamy sand, when water is applied on the soil surface using an one-line drip irrigation system and the soils are dried after the irrigation stops, respectively. Water contents through each soil profile were continuously monitored using three Sentek probes, each consisting of three capacitance sensors at 10, 20, and 30cm depths. Spatial variability in water content for each soil type was strongly influenced by soil textural class. There were big differences in wetting pattern and the rate of downward movement between loam and sandy loam soils, showing that the loam soil had a wider wetting pattern and a slower rate of downward movement than did the sandy loam soil. The wetting pattern in loamy sand soil was not apparent due to a low variability in water content (< 10%) by a lower-water holding capacity as compared to those measured in the loam and sandy loam soils, implying that the rate of water drainage below a depth of 30cm was high. When soils were dried, there were highly exponential relationships between water content and time elapsed after irrigation stops ($r^2$${\geq}$0.98). It was estimated that equilibrium moisture contents for loam, sandy loam, and loamy sand soils would be 17.6%, 6.2%, and 4.2%, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.2
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• pp.195-202
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• 1995

This experiment was performed to characterize the optimum water table level for the growth and yield of barley(var. Olbori) and wheat(var, Grumil), Olbori and Grumil were grown in the 550 liter plastic pot filled with silt loam or sandy loam, During the whole growth period, the water table adjusted to be 20, 30, 40, 50, and 70cm, Higher water table was resulted in the decrease in plant height and top dry weight, but in the increase of the ratio of top to root dry weight, especially in barley, This suggested that high water table level affected more the growth of top than that of root, The number and area of green leaves were decreased as the water table was higher than 30 to 40cm at the late growth period(May 18, 1993), The largest number and area of green leaves were shown at 50cm of water table in sandy loam and at 70cm in silt loam, As the water table was high, the leaf chlorophyll content was low, And barley was affected more significantly than wheat by soil texture, The photosynthetic activity was decreased remarkably at 20cm water table, Heading period was 2 to 3 and 4 days earlier at the 20cm water table of sandy loam in barley and wheat, respectively, However this earlier heading was not shown in silt loam, Grain filling was accelerated 5 to 7 days earlier in barley and 10 days in wheat grown at 20cm water table, The highest yield was present at 50 and 70cm water table, The yield was decreased remarkably at 20cm water table, resulting that yield reduction ratio of barley was 71.1% and 72, 2%, and that of wheat was 41.0% and 60, 0% in sandy loam and silt loam, respectively, High water table decreased the number of spike per unit area, but increased the seed weight per spike in barley, However, High water table reduced the seed weight per spike in wheat. There was significant correlation between yield and leaf chlorophyll content in wheat and barley, Yield was correlated significantly with green leaf area in barley, and with top dry weight, ratio of top to root dry weight chlorophyll content and photosynthetic activity in wheat. The optimum water table was 50 to 70cm in wheat and barley, They grew fairly well at 30cm water table of sandy loam, and at 40cm of silt loam.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.239-253
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• 1999

The objective of this study was to determine the effects of various kinds of composts on the change of soil chemical properties in upland soils. Field experiments were conducted in the loam and sandy loam soils. Various kinds of composts such as poultry manure compost(PMC), cow manure compost(CMC), human excrement sludge(HES), and food industrial sludge compost(FISC) were applied annually at rates of 0, 40, and $80Mg\;ha^{-1}$ to soils grown with soybean and maize plants for 4 years during 1994 to 1997. The results of this study were as follows : The continuous application of human excrement sludge decreased soil pH up to 4.4~5.0, while other compost treatments increased soil pH compared with control plot. The EC increased initially and showed their maximum values at 20days after compost application, and then decreased up to 40 days, thereafter kept a certain level. The available phosphorous accumulated at 0~20cm depth in loam soil, and 0~50cm in sandy loam soil. Annual accumulation rates were 17% higher in sandy loam soil than loam soil. The more compost application rates and times, the higher base saturation percentage increased in upland soils. Four year's application at a rate of $80Mg\;ha^{-1}$ per year increased the base saturation percentage to 87~91% compared with 45% at control plot in the loam soil. While in sandy loam soil only three year's application of same rate increased the base saturation percentage to 81~92% compared with 30.4% at control plot. The average annual increasing rate of base saturation percentage at the same application rates of composts were higher in sandy loam soil by 2.0~3.7 times than in loam soil. The application of compost increased the exchangeable Ca, Mg, and K contents of soils by 2, 2~3, and 3~5 times, respectively, compared with the control. The contents of exchangeable canons were high in surface soil. and decreased with increase of soil depths. In the case of heavy metal content, there were no difference at the application of PMC and CMC but Ni. Fe, Zn, Cu was increased a little when the HES applied, and Ni and Cr was increased application with FISC.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.6
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• pp.399-407
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• 2008

Importance of climate change and its impact on agriculture and environment has increased with a rise of greenhouse gases (GHGs) concentration in Earth's atmosphere, which had caused an increase of temperature in Earth. Greenhouse gas emissions such as methane($CH_4$) and nitrous oxide($N_2O$) in the field need to be assessed. GHGs fluxes using chamber systems in the fields(2004~2005) with pepper cultivation were monitored at the experimental plots of National Academy of Agricultural Science(NAAS), Rural Development Administration(RDA) located in Suwon city. $N_2O$ emission during pepper growing period was reduced to 74.0~82.1% in sandy loam soil compared with those in clay loam soil. Evaluating $N_2O$ emission at different levels of soil water conditions, $N_2O$ emission at -50 kPa were lowered to 13.2% in clay loam soil and 40.2% in sandy loam soil compared with those at -30 kPa. $CH_4$ emission was reduced to 45.7~61.6% in sandy loam soil compared with those in clay loam soil. Evaluating $CH_4$ at different levels of soil water conditions, $CH_4$ emission at -50 kPa was lowered to 69.6% in clay loam soil and 55.8% in sandy loam soil compared with those at -30 kPa. It implied that -50 kPa of soil water potential was effective for saving water and reducing GHG emissions. From the path analysis as to contribution factors for $N_2O$ emission, it appeared that contribution rate was in the order of mineral N(51.2%), soil temperature (25.8%), and soil moisture content(23.0%) in clay loam soil and soil moisture content(39.3%), soil temperature (36.4%), and mineral N(24.3%) in sandy loam soil.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.1
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• pp.16-25
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• 1992

A pot experiment was conducted to understand effect of soil temperaute on soybean shoot and root growth, and its relations to nutrient uptake including phosporus and potassium. Pregerminated soybean seedlings, Paldal cultivar, were planted for 43 days on the pots with Ihyeon silt loam and Samgag sandy loam in the temperature controled water baths at 17, 25 and $32^{\circ}C$. Shoot and root samples were taken at four times and analyzed. Shoot and root dry matter weights were heavier as higher soil temperaure. The root dry matter increased faster than shoot at earlier period. Shoot dry matter weights grown at 17 and $25^{\circ}C$ showed little difference between two soils, however, those grown in silt loam at $32^{\circ}C$ were heavier than sandy loam. The total lengths of roots were longer as higher soil temperature, and longer in silt loam than sandy loam. The roots grown in sandy loam at low temperature were thicker than the roots grown in silt loam at high temperature. The uptakes of phosphorus and potassium were higher as higher tempeature with same trend with dry matter. The uptake rate of unit root surface area was higher in sandy loam soil than silt loam. The uptake rates showed strong dependence on soil temperature as well as dependence of water uptake rate. Based on Dalton and Gardner model, at high temperature the dependence trend of phosphorus and potassium on soil temperature showed with active uptake model, while at low temperature the dependence showed without active uptake model.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.6
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• pp.416-431
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• 2000

The objective of this study was to determine the effects of various kinds of composts on the change of soil chemical properties in upland soils. Field experiments were conducted in the loam and sandy loam soils. Various kinds of composts such as poultry manure compost(PMC), cow manure compost(CMC), human excrement sludge(HES), and food industrial sludge compost(FISC) were applied annually at rates of 0, 40, and $80Mg\;ha^{-1}$ to soils grown with soybean and maize plants for 4 years during 1994 to 1997. The results of this study were as follows : The continuous application of human excrement sludge decreased soil pH up to 4.4~5.0, while other compost treatments increased soil pH compared with control plot. The EC increased initially and showed their maximum values at 20days after compost application, and then decreased up to 40 days, thereafter kept a certain level. The available phosphorous accumulated at 0~20cm depth in loam soil, and 0~50cm in sandy loam soil. Annual accumulation rates were 17% higher in sandy loam soil than loam soil. The more compost application rates and times, the higher base saturation percentage increased in upland soils. Four year's application at a rate of $80Mg\;ha^{-1}$ per year increased the base saturation percentage to 87~97% compared with 45% at control plot in the loam soil. While in sandy loam soil only three year's application of same rate increased the base saturation percentage to 81~92% compared with 30.4% at control plot. The average annual increasing rate of base saturation percentage at the same application rates of composts were higher in sandy loam soil by 2.0~3.7 times than in loam soil. The application of compost increased the exchangeable Ca, Mg, and K contents of soils by 2, 2~3, and 3~5 times, respectively, compared with the control. The contents of exchangeable cations were high in surface soil, and decreased with increase of soil depths. In the case of heavy metal content, there were no difference at the application of PMC and CMC but Ni, Fe, Zn, Cu was increased a little when the HES applied, and Ni and Cr was increased application with FISC.