• Korean Journal of Soil Science and Fertilizer
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• v.23 no.1
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• pp.26-33
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• 1990

The pot experiment was conducted to compare the effects of BIO-COM (Organic fertilizer made from industrial by-product) with the compost and humic acid on the physico-chemical properties of soils and the yield of paddy rice (CV. Chucheong-byeo). The results obtained were as follows: 1. All the fertilizer treatments, except humic acid, increased rice yield compare to no fertilizer treatment, and Bio-Com was the highest among the fertilizer treatments. 2. Rice yields were increased with increasing BIO-COM only up to 4% but 2% with N.P.K. fertilizers. 3. Rice yield showed highly positive correlation with number of panicle per hill but negative correlation with 1000 grain weight. 4. BIO-COM application induced the noticeable increase of pH, EC, OM, T-N, Av-P, Ex-Ca, Ex-Mg, Ex-Na, and $Av-SiO_2$, contents in the soils after experiments, and there were highly significant positive correlation among them. 5. BIO-COM application was positively affected on plant height, number of tiller, and fresh weight and dry weight of rice plant throughout entire growing stages and these are positively correlated with rice yield. 6. BIO-COM application also induced the increase of chlorophyll, N, P, Ca, and Mg contents in rice plant 7. It is revealed that there were highly positive correlations between rice yields and pH, EC, OM, T-N, Ex-Ca, and Ex-Mg in the soils. 8. It was also shown the highly significant positive correlations between rice yields, and N and P contents in the rice plant at heading stages, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.4
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• pp.69-76
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• 2016

To produce the primary data for best management of soil nutrient in organically practiced soils, 75 leading organic farms whose paddy fields were certified as organic were selected. Soil samples were collected from the paddy fields before plowing, and then analyzed for the determination of physico-chemical properties. Soil pH, organic matter and available phosphate were analyzed and averaged 6.2, $25.6mg\;kg^{-1}$ and $88.4mg\;kg^{-1}$, respectively. Contrary to the national-scale-surveyed paddy soils including organic and conventional farming, pH was higher, available phosphate was lower in the organically practiced soils, but organic matter was similar. With the increasing cultivation period in organic, soil pH and porosity were also increased, EC, available phosphate, bulk density and soil hardness were lower than those from the national survey. Organic matter, however, was not significantly changed. The bulk density was negatively correlated with the organic matter content for both surface topsoil ($R^2=-0.5424$) and subsoil ($R^2=-0.6429$) (p<0.05). Soil quality is improved in most of soil chemical and physical composition factors excluding organic matter and available phosphate. However, it is necessary to establish the counter measure plan for organic matter management and to develop phosphate-containing materials which can be used as organic agricultural material in the future.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.1
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• pp.33-39
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• 1994

This survey was conducted to investigate the factors affecting on salt accumulation and chemical components of soils cultivated with horticulture crops in plastic film houses. The soil samples were taken from 40 sites in the northern central areas of Korea and were analyzed for the chemical properties and soil separates. The data were evaluated with soil texture and years of cultivation as major factors. The results are summarized as follows : 1. The chemical properties of surface soils in plastic film house were pH 5.80, EC $3.59mScm^{-1}$, O.M. 4.20%, Av. $P_2O_5$ 1,178ppm, $NO_3-N$ 180ppm, Av. $SO_4{^{2-}}$ 353ppm, $Cl^-$ 240ppm, Ex. Na 0.40me/100g. 2. Compared to the outside soil of plastic film house, the inside soil had 2.5~3 times higher contents of $NO_3-N$, Av. $SO_4{^{2-}}$ and $Cl^-$, 1.2~1.8 times higher exchangeable base elements, and 2.8 times higher electrical conductivity. But pH value of the inside soil was lower than the outside soil by 0.3 pH unit. 3. Soil texture classification showed that sandy loam, loam and silt loam were 32.5 %, 37.5 %, and 30.0 %, respectively. The contents of $NO_3-N$, Av. $SO_4{^{2-}}$, $NH_4-N$ and EC value were very high in silt loam soils. Av. $P_2O_5$ content and pH value of sandy loam soils were higher than those of silt loam and loam soils. 4. The contents of O.M. and Av. $P_2O_5$ were higher in long term cultivation, but the contents of $NO_3-N$, Av. $SO_4{^{2-}}$, $Cl^-$, Ex. Mg and Ex. Na including EC of the soil with 2~4 years cultivation were higher than those of the soil with above 5 years cultivation. 5. Multiple linear regression analysis showed that contribution degree of soil chemical properties to the EC was high in the order of $NO_3-N$ > Av. $SO_4{^{2-}}$ > Ex. Na > $Cl^-$ > Av. $P_2O_5$ > $NH_4-N$ > Ex. Mg>Ex. Ca. Among the soil chemical properties the contribution of anions was remarkably high. 6. EC value correlated with ${\sum}A$(total content of anions)as $r=0.932^{**}$ and with ${\sum}C$(total content of cations) as $r=0.452^{**}$.

• Journal of Soil and Groundwater Environment
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• v.22 no.1
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• pp.49-58
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• 2017

Biotic ligand model (BLM) and species sensitivity distribution (SSD) were used to determine the site-specific Cu threshold concentration (5% hazardous concentration; HC5) in soil pore water. Model parameters for Cu-BLM were collected for six plants, one collembola, and two earthworms from published literatures. Half maximal effective concentration ($EC_{50}\{Cu^{2+}\}$), expressed as $Cu^{2+}$ activity, was calculated based on activities of major cations and the collected Cu-BLM parameters. The $EC_{50}\{Cu^{2+}\}$ varied from 2 nM to $251{\mu}M$ according to the variation in environmental factors of soil pore water (pH, major cation/anion concentrations) and the type of species. Hazardous activity for 5% (HA5) and HC5 calculated from SSD varied from 0.076 to $0.4{\mu}g/L$ and 0.4 to $83.4{\mu}g/L$, respectively. HA5 and HC5 significantly decreased with the increase in pH in the region with pH less than 7 due to the decrease in competition with $H^+$ and $Cu^{2+}$. In the region with pH more than 7, HC5 increased with the increase in pH due to the formation of complexes of Cu with inorganic ligands. In the presence of dissolved organic carbon (DOC), Cu and DOC form a complex, which decreases $Cu^{2+}$ activity in soil pore water, resulting in up to 292-fold increase in HC5 from 0.48 to $140{\mu}g/L$.

• Journal of Korean Society of Forest Science
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• v.85 no.4
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• pp.634-646
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• 1996

This study was carried out to reveal the forest land effect on water purification in mountainous watersheds. Rainfall, throughfall, stemflow, soil and stream water were monitored by pH, electrical conductivity(EC), and dissolved oxygen(DO) in Daehan-Ri and Parkdal-Ri catchments. The results were summarized as follows; 1. Rainfall pH values of Parkdal-Ri and Daehan-Ri were 7.6 and 6.4, respectively. 2. Comparing stemflow and throughfall of Pinus densiflora with Pinus rigida, the pH values of Pinus densiflora were 4.32 and 4.22 and the pH of Pinus rigida were 3.34 and 4.81, respectively. The EC values of Pinus densiflora were $119.7{\mu}S/cm$ and $96.8{\mu}S/cm$ and EC of Pinus rigida were $230.0{\mu}S/cm$ and $82.0{\mu}S/cm$. 3. All pH values were decreased as the streamflow increased except long-term runoff in Daehan-Ri. The EC values also were increased as the streamflow increased, but EC of short-term runoff in Daehan-Ri was gradually decreased as the streamflow increased due to entrance of throughfall which has high EC values at the beginning of rainfall events. The DO concentrations of all experimental plots were elevated as the streamflow increased, because reaeration occurs at the surface of the stream as the increased discharge make turbulence. 4. pH of Stemflow and throughfall in Pinus densiflora were lower than in Quercus acutissima, but EC values were higher in Pinus densiflora. 5. Water purification was mostly influenced by forest soil in forest hydrological processes. 6. Stemflow and throughfall were more influenced by dry deposition and organic acid in crown and bark than those of wet deposition. During the stemflow and throughfall passed forest soil, these acidic stemflow and throughfall were neutralized, and stream water quality was neutral or slightly alkaline.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.4
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• pp.398-404
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• 1999

Factor analysis technique was employed to screen the principal indicators influencing soil and water qualities in the intensively cultivated areas of the Han River Basin. Soil chemical parameters were analyzed for the soil samples collected at intensive farming area in Pyungchang-Gun, and water quality monitoring data were obtained from the agricultural small catchments of Han River Basin during 1996 and 1997. Among the $11{\times}11$ cross correlation matrix, 29 correlations were significant out of 55 soil quality indicator pairs. The overall Kaiser's measure of sampling adequacy(KMS) value was acceptable with 0.60. Most indicators except iron were acceptable. Among soil indicators, the first factors showing high factor loadings were pH, Ca and Mg. The factor loading was the highest for Ca. The second factor could be characterized as phosphate and micronutrient. The third factor was organic matter and EC, and the fourth factor was potassium and Fe. Out of 190 water quality indicators, 86 correlations were significant. Overall KMS value was 0.74, but the KMS values for pH, TSS, Cd, Cu and Fe were lower than 50. The first factor of EC accounts 27.1 percents of the total variance, and showed high factor loadings with Na, Ca, $SO_4$, Mg, K, Cl, $NO_3$, and T-N. The second factor showed high loadings with Zn, Fe, Mn and Cd. The third to seventh factors could be characterized as $PO_4$, TSS, inorganic nitrogen, pH and T-P, and Cu factors, respectively. The factor score for EC was the highest in Kuri, followed by Chunchon, Dunnae and Daegwanryng. The factor score for heavy metals were the highest in the Daegwanryng. The results demonstrated that the factor analysis could be useful to select the most principal factor influencing soil and water qualities in the agricultural watershed.

• Journal of Bio-Environment Control
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• v.13 no.2
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• pp.102-106
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• 2004

Objective of this research was to investigate the effect of fertigation setting point such as -5, -10, -20, and -30 ㎪ on the growth and fruit quality of sweet pepper (Capsicum annuum L.) in greenhouse culture. The net $CO_2$ assimilation and transpiration rate were the lowest in the treatment of -30㎪. The pH and EC in soil solution were not severly affected by irrigation setting point and no statistical differences were observed among treatments of irrigation setting point tested. The N content of above ground plant tissue was the lowest in the treatment of -30 ㎪ and those of K, Ca, and Mg were the highest in the treatment of -10 ㎪. But that of P did not show statistical differences among treatments tested. As the fertigation setting point was getting low, the growth decreased at 60th day after planting, while there were no differences among treatments at 210th day after planting. The fruit quality except sugar contents did not show differences among treatments, but sugar contents was the highest in the treatment of -30 ㎪ with $8.0^{\circ}$Brix. Above results indicated that fertigation setting point should be in the range from -10 ㎪ to -20 ㎪ to ensure good crop growth and fruit quality in sweet pepper production.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.1
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• pp.67-78
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• 2017

The purpose of this study was to investigate the effect of humic acid on the germination, the growth and the yield of hot pepper when treated with organic hot pepper seedlings and growing season. The germination rate of 0.05% and 0.1% humic acid was higher than that of untreated, but the germination rates of 0.4% and 1.0% humic acid were 90.0% and 86.7%, respectively, compared with the control treatment (96.7%). At 30 days after transplanting, hot pepper treated with low (0.05%) or high (1.0%) concentration of humic acid decreased the growth of hot pepper seedlings, whereas 0.2% humic acid treatment significantly increased a average height (97.6 cm), leaf number (84.7) and fresh weight ($128.1g\;plant^{-1}$) of hot pepper. After 60 days of treatment with humic acid, the height of hot pepper was significantly longer in 0.2% humic acid. The mean green fruit number of 0.2%, 0.1% and 0.05% humic acid were not significantly different among the treatments, but the mean green pepper number of 0.4% and 1.0% humic acid treatments were the higher with 35.2% and 29.1%, respectively than other treatments. However, the fresh weight of green pepper was found to be $111.5g\;plant^{-1}$ more heavier than the untreated in 0.2% humic acid. The total ($5.8kg\;plant^{-1}$) and average ($1.4kg\;plant^{-1}$) fresh weight of pepper were higher than that of untreated control, except for the 1.0% humic acid treatment after 60 days of soil irrigation. The total weight of hot pepper treated with 0.2% and 0.1% humic acid treatment was $9.3kg\;plant^{-1}$ and $8.6kg\;plant^{-1}$, respectively, which were heavier than the other treatments. The effect of humic acid concentrations on soil microbial populations, pH and EC was investigated. The soil bacterial population density of 0.2% humic acid treatment was 3.5 times higher than that of untreated control soil. As the concentration of humic acid increased from 0.05% to 1.0%, pH and EC of hot pepper grown soil also increased.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.963-969
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• 2011

The river-bed sediments from the major river basins were analysed for the chemical and physical properties to evaluate environmental safety for the agricultural uses. The samples were taken from 16 sites of Han river, 36 of Geumgang river, 27 of Yeongsan river, and 140 of Nakdong river. The total of 219 samples from the 28 counties were taken from the surface of the sediments at the depth of 50 cm. The particle density of the sediments was greater than $2.63Mg\;m^{-3}$ and the whole range of the density was $2.60{\sim}2.69Mg\;m^{-3}$, the average particle size was 0.7 mm whereas the size range was 0.075~0.85 mm. The analyses of the particle sizes by basins showed that Han and Geumgang river had particle sizes of 0.075~0.85 mm, while Geumgang and Yeongsan river had particle sizes of 0.25~0.85 mm. Geumgang and Yeongsan river tended to have greater particle sizes. The average values of the chemical properties were 6.3 for pH, $0.16dS\;m^{-1}$ for EC, $8g\;kg^{-1}$ for organic matter, $101mg\;kg^{-1}$ for available phosphate, 0.39, 3.47, and $0.93cmol_c\;kg^{-1}$ for exchangeable potassium, calcium, and magnesium respectively. The greatest property at each basin was pH for Han river, Ec, available phosphate and exchangeable sodium for Geumgang river, organic matter, exchangeable calcium and magnesium for Yeongsan river, and exchangeable potassium for Nakdong river.

• Journal of Practical Agriculture & Fisheries Research
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• v.23 no.2
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• pp.51-61
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• 2021

As a result of examining the germination rate between ginseng varieties, Jagyongjong varieties had the highest germination rate, and Yeonpung. had the lowest germination rate. In the ginseng seed germination rate experiment, the highest germination rate and growth condition were shown in artificial soil conditions of the ratio of Peatmoss 6.5: Pearlite 2: Masato 1.5. Good soil conditions require adequate soil moisture forces during the incubation period. The cultivation of ginseng medicinal crops requires optimal soil breathability, soil pH, and soil stabilization, which are important for root breathing. Microbial activity in the soil has a great influence on the growth of ginseng. The optimum pH of the soil for ginseng cultivation is 5.0-5.5 As a result of the experiment, the soil remained in an appropriate range after a month. In general, when the EC concentration value of the soil for ginseng cultivation is 0.2 mS/cm or more, growth deteriorates, and when the EC concentration value is 0.5 mS/cm or more, concentration obstacles such as root decay occur. As a result of the analysis, the higher the concentration value of EC, the more likely it is to interfere with ginseng growth.