• Magazine of the Korean Society of Agricultural Engineers
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• v.27 no.1
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• pp.37-45
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• 1985

To define the amount of consumptive use of upland crops, the moisture consumption characters were investigated with different soil moisture content by soil properties(loam, sandy loam, sand) at the experimental farm of Kon-Kuk University from April 20 to July 20 1984. The results obtained are summarized as follows; 1. Total moisture consumption under bare soil condition had an order of loam> sandy loam> sand and showed an order of pF 1.5> pF2. 1> pF 2.7 by re-irrigation point and the average during the experimental period (92days) was 435. 9mm and the daily average moisture consumption was 4. 7mm. 2. The moisture consumption characters of bare soil plot obtained showed that the amount of irrigation water per one time and the days of intermission increased and, on the contrary, the times of irrigation and the total amount of irrigation water decreased by the increment of re-irrigation point in the same soil 3. Total moisture consumption of spring cabbage under open cultivation showed 528.6 rim in maximum and had an order of loam> sandy loam> sand. In the aspect of rc-irrigation point, it had an order of pFl. 5> pF 2.1> pF 2.7. In case the planning basic year was taken into account, the amount of irrigation water needed for open cultivation was 456. 3 mm and its average daily moisture consumption was 6. 2mm. 4. Total moisture consumption of summer cucumber under open cultivation showed 635. 8mm in maximum and had an order of loam> sandy loam> sand. In the aspect of re-irrigation point, it had an order of pF 1.5> pF2. 1> pF2. 7 In case the planning basic year was taken into consideration, the amount of irrigation water was 516. 9mm and its aversge daily moisture consumption was 6. 5mm. 5. The result of cabbage cultivation showed its maximum yield in loam soil when the pF values were maintained from 1,5 to 2.1 and then the evapotranspiration ratio was 1, 76 and also when the amount of irrigation water were similar, it showed effective to reduce the days of intermtission. 6. The result of cucumber cultivation showed its maximum yield in sandy loam soil when the pF value maintained from 1.5 to 1.7 and when the irrigation point maintained at pF 2,7 in sandy soil, its yield was severely decreased.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.1
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• pp.149-158
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• 2007

To investigate the characteristics of the nitrogen mineralization of oil cakes according to changes in temperature(10, 20, $30^{\circ}C$) moisture(40, 50, 60, 70% of field capacity in loam and 50, 60, 70, 80% of field capacity in sandy loam), mineral nitrogen was measured in soil after incubation for 30 days. In addition, the mineralization in sandy loam and loam which had different soil texture were compared. According to incubating the castor seed, soybean, and rice bran cakes with soil, the higher the temperature and moisture content were, the higher the content of mineral nitrogen was observed. The content of mineral nitrogen was higher in sandy loam than loam. The content of mineral nitrogen was decreased with soil depth increasing and was also higher in sandy loam than loam.

• Journal of Bio-Environment Control
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• v.17 no.2
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• pp.162-169
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• 2008

To determine suitable composition of nutrient solution according to soil textures in fertigation culture of cucumber using three strengths (S) of Yamasaki cucumber recipe, chemical changes of soil, growth characteristics and yield of cucumber were investigated. Electric conductivity of drainage solution was risen in all treatments, pH of loam soil was generally optimum level and that of sandy soil was high level. Photosynthetic rate in loam soil supplied the 1/2 S and transpiration rate in sandy soil supplied the 1.0 S were most low. Diffusive resistance in sandy soil supplied the 1.0 S was high. Chlorophyll contents was higher concentrations by the kinds of soil. Amount of drainage solution in sandy loam soil supplied the 1/2 S and loam soil supplied the 1.0 S were most much and little, respectively. Water absorption rate was the opposition to amount of drainage solution. Nutrient contents in soil except calcium were most high in the 1.0 S by the kinds of soil. Nutrient contents in leaves, nitrogen in sandy soil supplied 1.0 S, phosphorus in loam soil supplied 1/2 S, potassium in two soil supplied 1.0 S, calcium in loam supplied 1/2 S and sandy loam soil supplied 1.0 S, magnesium in loam soil supplied the 1/2 S was high. The growth and yield of fruit were more in loam than in sandy loam soil. Therefore, the suitable compositions of macro-nutrients for fertigation culture of cucumber were determined in loam and sandy loam soils as follows: In loam soil, they were $NO_3$-N 12.3, $NH_4$-N 1.0, P 3.0, K 5.9, Ca 5.7, Mg $3.5\;me{\cdot}L^{-1}$, whereas in sandy loam soil $NO_3$-N 11.7, $NH_4$-N 1.0, P 3.0, K 5.9, Ca 4.9, Mg $3.2\;me\;L^{-1}$.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.3
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• pp.220-225
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• 1994

This study was conducted to investigate the influence of treatment of fly ash on heavy metal contents in the grain. 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. Also. rice and soybean were cultivated the same types of paddy and upland field with those ashes of 0, 12ton/10a and 0, 9ton/10a, yearly for three years. At the harvest time, the heavy metal contents in rice and soybean were Investigated. The results were summarized as follows : 1. Amount of application. 1) The contents of Cd in brown rice increased in the clay loam soil. Cr and Ni increased sandy loam soil with the application of anthracite fly ash. 2) The contents of Zn in rice increased in the sandy loam soil with the application of bituminous coal fly ash. 3) The contents of Cu in soybean increased with the application of anthracite and bituminous coal fly ash, but Zn, Pb, Cr and Ni increased only with the bituminous. 2. Successive application. 1) The contents of Cd in brown rice increased in the clay and sandy loam soil, however Cu, Zn, Ni, Cr and Fe increased only in sandy loam soil with the anthracite fly ash. 2) The contents of Cr in soybean were increased in the clay and sandy loam soil, but Cu, Fe increased only sandy loam soil with anthracite fly ash. 3) The contents of Cd, Zn, and Cr in brown rice increased in the clay and sandy loam soil, but those of Cu, Mn increased only in the sandy loam soil with application of bituminous. 4) The contents of Cd, Pb, and Cr in soybean increased in the sandy loam soil with the application of bituminous coal fly ash.

• Journal of Biosystems Engineering
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• v.17 no.3
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• pp.237-246
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• 1992

This study was conducted to investigate experimentally the effect of track tension on the tractive performance of rice combine. The experiment was carried out at the two in-door soil bins with soil types of loam and sandy loam. The initial track tension was varied by three different values of 0.71, 1.75 and 3.84kN at three different forward velocity settings of 0.17, 0.32 and 0.45m/s, respectively. The data acquisition system was designed and used for the measurement of pull, driving axle torque and its velocity under the test conditions to calculate the tractive efficiency. Results of the study were summarized as follows : 1) The effect of the initial track tension on the tractive efficiency was found being significantly dependent on soil types but not on forward velocities. Therefore, the benifit of adjusting the initial track tension may be obtained when the types of soils on which combines operate are changed. 2) In loam, tractive efficiency decreased with increase in track tension. However, it increased in sandy loam until it reached to a peak value and then decreased with increase in track tension. 3) The maximum tractive efficiency of the tested combine was obtained with an initial track tension of about 1.75kN on sandy loam, and below that on loam at about 5% slippage without being noticeably influenced by the forward velocity.

• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.375-383
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• 2020

BACKGROUND: Bisphenol A (BPA) is a chemical widely used in polycarbonate plastics, epoxy resins. BPA is an endocrine disruptor. Residue of BPA in agricultural environments is a major concern. The objective of this study was to understand the characteristics of the uptake and distribution of BPA and its metabolites introduced into the agricultural environment to crops, and to use it as basic data for further research on reduction of BPA in agricultural products. METHODS AND RESULTS: This study established the analysis method of BPA and its metabolites in soil and crops, and estimated the intake of BPA and its metabolites from lettuce (Lactuca sativa) grown in sandy loam and loam soil, which are representative soils in Korea. The two major metabolites of BPA were 4-hydroxyacetophenone (4-HAP) and 4-hydroxybenzoic acid (4-HBA). BPA, 4-HAP and 4-HBA have been analyzed by using liquid chromatography tandem mass spectrometry (LC-MS/MS). These substances were detected in sandy loam and loam soil, indicating that certain portions of BPA were converted to 4-HAP and 4-HBA in the soil; however, it was observed that only 4-HBA migrated to lettuce through the roots into crops. CONCLUSION: The uptake residues showed the BPA and 4-HAP were not detected in lettuces grown on sandy loam (SL) and loam (L) soil treatments that were applied with of 10 ng/g, 50 ng/kg and 500 ng/g of BPA. However, the 4-HBA was detected at the level of 7 ng/g and 11 ng/g in the lettuce grown in sandy loam and loam soil that were treated with the 500 ng/g of BPA, respectively, while the 8 ng/g of 4-HBA was measured in the lettuce cultivated in the loam that was treated with 100 ng/g of BPA. This result presents that the BPA persisting in the soil of the pot was absorbed through the lettuce roots and then distributed in the lettuce leaves at the converted form of 4-HBA, what is the oxidative metabolite of BPA.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.3
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• pp.144-150
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• 2006

Chemical characteristics and their interrelationships of 156 soils included by 74 sandy loam and 82 loam soils collected from plastic film house in Chungbuk area were investigated from 1998 to 2001. Seventeen chemical properties including pH, organic matter (OM), electrical conductivity (EC), inorganic nitrogen, available phosphorus, exchangeable cations, CEC, etc., were analyzed by correlation, standardized partial regression coefficient, and principal factor analysis. Standardized partial regression coefficients of chemical properties were estimated to determine the degree of contribution of EC and OM contents in soils. Principal factor analysis was applied to classify the studied chemical properties into different groups having similar chemical properties. The pH of experimental soils ranged from 4.24 to 7.14 and 4.95 to 7.35 for loam and sandy loam soils, respectively. The EC of soils varied from 0.93 to $15.65dS\;m^{-1}$ for loam and $0.91{\sim}22.30dS\;m^{-1}$ for sandy loam soils, respectively with significant differences among them. The EC measured by 1:5 $H_2O$ dilution method and saturation method were significantly related with 8.163 and 8.599 as the slopes of regression equation for loam and sandy loam soils, respectively. These slopes more than 8.0 in this regression equation was higher than the slope of 5.0 that is estimated from dilution coefficient suggesting that EC measured by 1:5 dilution method might be erratic. The standardized partial regression coefficient of different chemical properties for the estimation of EC was in the order of $NO_3{^-}$ > $Cl^-$ > OM > exchangeable Mg for loam soils and $NO_3{^-}$ > exchangeable Mg > $Cl^-$ for sandy loam soils. Contribution order of the chemical properties based on standardized partial regression coefficient differed 1:5 dilution method and saturation method, indicating that different chemical compounds might be present in the extract solutions of these two methods. Consequently the measurement of EC by saturation method was thought be still better for estimation of chemical property because accuracy of EC measurement by 1:5 dilution method can't be improved by any specific coefficient for adjustment of EC. Regardless of differences in soil textures and extraction methods, correlation coefficients between EC and the other chemical properties were routinely in the order of $NO_3{^-}$ > $Cl^-$ > degree of base saturation > exchangeable Mg > exchangeable Ca > $SO{_4}^{2-}$. The principal factor analysis revealed four factor groups of the chemical properties studied. The groups for sandy loam were as follows; ; 1. salt components, 2. soil reaction components, 3. fixed and adsorption components, 4. CEC components. The groupings of loam soils were similar to sandy loam except that exchangeable Na substituted the CEC of sandy loam.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.5
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• pp.365-372
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• 2001

The objective of this study was to determine the effects of various kinds of composts on the change of soil physical properties and microorganism in upland soils. Field experiments were conducted in the loam and sandy loam soils, while the clay loam and sandy loam soils were used for laboratory experiments. Various kinds of composts such as poultry manure compost(PMC). cow manure compost(CMC). human excrement sludge(HES), and food industrial sludge compost(FISE) 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 : Bulk density of loam soil decreased with compost application to $1.07{\sim}1.32Mg\;m^{-3}$ compared with $1.49Mg\;m^{-3}$ of control plot, while in sandy loam soil it decreased to $1.00{\sim}1.20Mg\;m^{-3}$ compared with $1.25Mg\;m^{-3}$ of control plot. Bulk density of soil was decreased according to maize cultivation compared with bare control, but soybean cultivation was similar. Population of organic material decomposing microorganisms was increased rapidly at the initial incubation stage at $25^{\circ}C$, and increased more sensitively at the loam soil than sandy loam soil. In the case of the change of microorganisms associated with nitrogen circulation, ammonia oxidizing bacteria was more at the initial incubation stage, and denitrifying bacteria was more at the initial incubation stage, and denitrifying bacteria increased until 1~4 weeks after incubation and increased more at the loam soil than sandy loam soil.

• Journal of Ginseng Research
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• v.13 no.1
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• pp.84-91
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• 1989

This study was conducted to Investigate the effects of physico-chemical soil properties on the growth and yield of ginseng. 1 In the field survey, the yields of 6 year old ginseng were 2.46 Kg/3.3$m^2$, 2.13 Kg/3.3$m^2$, 1.44 Kg/3.3 $m^2$ in clay loam, loam and sandy loam soils, respectively 2. The missing plant rate for il year old ginseng were 33.6% and 51.6% in clay loam and sandy loam soils, respectively : the stem length and stem diameter of ginseng plants in sandy loam soil were smaller than those in clay loam soil. 3. Soil aggregation and porosity we're slightly higher in 6 year old ginseng fields than in 2 year ones. 4. Inorganic-N increased in 2 year and 3 year old ginseng fields reaching up to 100-120ppm, however it 1 decreased to 75 ppm, 34 ppm and 25 ppm in 4, 5 and 6 year old ginseng fields, respectively, It varied 1 more greatly in sandy loam soil than in clay loam. 5. The $P_2O_5$, K, Ca, and Mg contents differed little with plant age. Sandy loam had high N and $P_2O_5$ contents but low cation contents. 6. The yield of 6 year old ginseng fields were significantly correlated with clay contents and porosity. The missing Plant rate of 6 year old ginseng had a positive correlations with sand. and N contents.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.2
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• pp.158-164
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• 1996

This survey was conducted to investigate the distribution of heavy metal contents in medicinal plants and soils. Plant and soil samples were collected at 254 sites(Angelica gigas : 81, Astragalus membranceus : 38, Platycodn glandiflorum : 36, Paeonia albilora : 34, Codonopsis lanoceolata : 32, Ligusticum chuanxiong : 17, Bupleurum falcatum : 16, respectively) over the country, Soil texture, pH values and heavy metal content of soils and medicinal plants were evaluated as major factors. Soil texture classification showed that sandy loam, loam, loamy sand and silt loam were 46.1%, 26.0%, 19.3% and 8.6% of the total, respectively. The contents of O.M, Ex.Ca. Ex.Mg and EC value were higher in loamy(sandy loam, loam and silt loam)soils than in sandy(loamy sand)soils, but available $P_2O_5$ contents of loamy sand soils were higher than those of sandy loam, loam, and silt loam. The contents of Cd, Cu, Pb, Zn and Ni in soil were high in loamy soils, while Cr content was high in loamy silt soils. The contents of Cu and Cr in Angelica gigas were high in loamy soils, and those of Pb in Astragalus membranceus, Paeonia albiflora and Codonopsis lanoceolata were high in sandy loam soils. Correlation coefficients between heavy metal contents in medicinal plants and their soils with soil texture were positively correlated in sandy loam and loam at Cu, loam at Zn, sandy loam, loam and loamy sand at Cr, respectively. Correlation coefficients between pH value of the soils and contents of Cd, Zn and Ni in medicinal plants were negatively correlated, but those of Cd, Pb, Zn and Ni in soils were positively correlated.