• Korean Journal of Soil Science and Fertilizer
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• v.50 no.6
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• pp.520-529
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• 2017

In Korea, the largest agricultural lands are paddy fields which have poor infiltration and drainage properties. Recently, Korean government pursuits cultivating upland crops in paddy fields to reduce overproduced rice in Korea. In order to succeed this policy, it is critical to set criteria suitability classification for upland crops cultivating in paddy field soils. The objective of this study was developing guideline of suitability classification for sesame cultivation in paddy field soils. Yields of sesame cultivated in paddy field soils and soil properties were investigated at 40 locations at nationwide scale. Soil properties such as topography, soil texture, soil moisture contents, slope, and drainage level were investigated. The guideline of suitability classification for sesame was determined by multi-regression method. As a result, sesame yields had the greatest correlation with topography, soil moisture content, and slope. Since sesame is sensitive to excessive soil moisture content, paddy fields with well drained, slope of 7-15% and mountain foot or hill were best suit for cultivating sesame. Sesame yields were greater with less soil moisture contents. Based on these results, area of best suitable paddy field land for sesame was 161,400 ha, suitable land was 62,600 ha, possible land was 331,600 ha, and low productive land was 1,075,500 ha. Compared to existing suitability classification, the new guideline of classification recommended smaller area of best or suitable areas to cultivate sesame. This result may suggest that sesame cultivation in paddy field can be very susceptible to soil moisture contents.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.2
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• pp.93-97
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• 1977

A pot experiment was conducted to find out suitable method in determining the rate of phosphorus application. Soybean was planted under optimum moisture condition. The soils used in this experiment were cultivated and non-cultivated mineral soils, and volcanic ash soils. The results were summarized as follows: 1. Phosphorus adsorption maximum(PAM) was the good parameters to determine phosphorus adsorption capacity of all tested soils. 2. Phosporus adsorption maximum was increased with the content of ammonium acetate extractable aluminum, and the organic matter effects on PAM was considerably high in volcanic ash soils. 3. Requirement of phosphorus for maximum yields were in the range of 30~35% of PAM for tested soils. 4. PAM was considered as a suitable criteria to determine the rate of the phosphorus application and it was also considered to be more attractive than phosphorus absorption coefficient.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.5
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• pp.333-342
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• 2013

Soil compaction is affected by soil texture, organic matter (OM), strength (ST) and soil moisture, which is difficult to understand the degree and effects of related factors. The purpose of the study is to assess the impact of them on the compaction with bulk density (BD). The analysis was conducted with data collected from national-wide monitoring sites including 105 upland soils, 246 orchard soils, and 408 paddy soils between 2009 and 2012. The distributions of soil physical properties were measured. The correlation and multi linear regression analysis were performed between soil physical properties using SAS. The regression equation of BD(y) includes ST, gravitational water contents (GWC), and OM as variables commonly, having additional factors, clay content and sand content in paddy soil and upland soil for only subsoil (p<0.001). Our results show that the BD could be explained about 40~50% by various physical properties. The regression was mainly determined by ST in orchard and upland soil and by the GWC in paddy soil. To mitigate soil compaction, it is important to maintain the proper level of OM in upland soil and to consider the moisture condition with soil texture in paddy soil when making work plan. Furthermore, it would be recommended the management criteria classified by soil texture for the paddy soils.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.4
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• pp.295-304
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• 2015

To develop a technique for efficient management of fertility for cucumber in greenhouse, a quick test method to quantify nitrate ($NO_3{^-}$) content in soil solution and leaf petiole juice using a simple instrument that are easy to use for farmers was investigated. N fertilizer (urea) was applied at 0, 50, 100 and 200% levels of the recommended application rate from 30 days after transplanting to harvest by soil fertigation treatments. Stable results were obtained from analysis of nitrate ($NO_3{^-}$) using top $10^{th}$ or $11^{th}$ leaf petioles collected between 10 to 11 am in the morning. Under the semiforcing culture, $NO_3{^-}$ content of leaf petiole juice was highest at 60 days after transplanting (DAT) at all fertigation treatments. Appropriate $NO_3{^-}$content of leaf petiole juice was $2,418{\pm}78{\sim}2,668{\pm}118$ at 45 DAT, $3,032{\pm}90{\sim}3,332{\pm}63$ at 60 DAT, $2,709{\pm}50{\sim}3,158{\pm}155$ at 75 DAT, $2,535{\pm}49{\sim}2,907{\pm}83$ at 90 DAT, and $2,242{\pm}48mg\;L^{-1}$ at 105 DAT. In addition, appropriate $NO_3{^-}$ content of soil solution was $167{\pm}9{\sim}212{\pm}15$ at 45 DAT, $83{\pm}10{\sim}112{\pm}12$ at 60 DAT, $49{\pm}3{\sim}92{\pm}6$ at 75 DAT, $71{\pm}9{\sim}103{\pm}9$ at 90 DAT, and $73{\pm}9mg\;L^{-1}$ at 105 DAT. The cucumber yield at 100% N level of fertigation was $7,770kg\;10a^{-1}$ and no difference in yield was found at 200% N level of fertigation. However, there was 12% decrease in yield at 50% N fertigation and, 17% decrease at 0% N fertigation. Under retarding culture, $NO_3{^-}$ concentration of leaf petiole juice was highest at 55 days after transplanting (DAT) at all fertigation treatments. Appropriate $NO_3{^-}$ content of leaf petiole juice was $2,464{\pm}102{\sim}2,651{\pm}33$ at 45 DAT, $3,025{\pm}71{\sim}3,314{\pm}84$ at 55 DAT and $2,488{\pm}92mg\;L^{-1}$ at 65 DAT, respectively. Appropriate $NO_3{^-}$ content of soil solution was $111{\pm}10{\sim}155{\pm}14$ at 45 DAT, $93{\pm}7{\sim}147{\pm}14$ at 55 DAT, $67{\pm}4mg\;L^{-1}$at 65 DAT, respectively. The cucumber yield at 50% N fertigation was not different from $1,697kg\;10a^{-1}$ of 100% N fertigation level and even with that of the 200% N fertigation. However, there was 21% decrease in yield at 0% N fertigation.

• Korean Journal of Soil Science and Fertilizer
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• v.51 no.2
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• pp.128-141
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• 2018

Industrial complex releasing huge amounts of dusts, fumes and wastewater containing heavy metal(loid)s could be a source of heavy metal(loid)s pollution in arable soil. Heavy metal(loid)s pollution in arable soil adversely affect crops safety, subsequently human being. Hence, it is important to accurately assess the heavy metal(loid)s pollution in soil using pollution indices. The objectives of this study are 1) to compare assessment methods of heavy metal(loid)s pollution in arable soils located near industrial complex in Gyeongsang provinces and 2) to determine the relationship between concentration of plant available heavy metal(loid)s and chemical properties of soil. Soil samples were collected from 85 sites of arable lands nearby 10 industrial complex in Gyeongsang provinces. The average total concentration of all heavy metal(loid)s of the studied soils was higher than that of Korean arable soils but did not exceed the warning criteria established by the Soil Environmental Conservation Act of Korea. Only six sites of arable soils for the total concentration of As, Cu and Ni exceeded the warning criteria (As: $25mg\;kg^{-1}$, Cu: $150mg\;kg^{-1}$, Ni: $100mg\;kg^{-1}$). The contamination factor (CF) and geoaccumulation index ($I_{geo}$) of the heavy metal(loid)s in arable soils varied among the sampling sites, and the average values of As and Cd were relatively higher than that of other metals. Results of integrated indices of As and Cd in arable soils located near industrial complex indicated that some arable soils were moderately or heavily polluted. The plant available concentration of heavy metal(loid)s was negatively related to the soil pH and negative charge of soil. Available Cd, Pb, and Zn concentrations had relatively high correlation coefficient with pH and negative charge of soil when compared with other heavy metal(loid)s. Based on the above results, it might be a good soil management to control pH with soil amendments such as lime and compost to reduce phytoavailability of heavy metal(loid)s in arable soil located near industrial complex.

• Journal of Soil and Groundwater Environment
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• v.15 no.3
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• pp.44-51
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• 2010

Contamination of groundwater from point and non-point sources is one of major problems of water resource manangement in Jeju island. This study characterized groundwater and soil contamination in Hallim area which is one of the areas of significantly contaminated soil and groundwater in Jeju Island. The amount of loaded contaminant (ALC) of Jeju area was estimated as 13,212 ton N/yr and 3,210 ton P/yr, The ALC of Hallim area was amounted to 2,895 ton N/yr and 1,102 ton P/yr, which accounted for 21.9% and 34.3% of the Jeju's ALC, respectively. The soil pH values (5.6-5.9) were not much different in land use areas. By contrat, average cation exchange capacity (CEC) of 14.1 $cmol^+/kg$ was high comparing to the nationwide range of 7.7-10.9 $cmol^+/kg$. Further, Sodium adsorption ratios (SARs) of horse ranch, pasture, and cultivating land for livestock were as high as 0.19, 0.17, and 0.16 respectively, comparing to the other landuse areas. Nitrate nitrogen at 22.2% of total groundwater wells exceeded 10 mg/L (the criteria of nitrate nitrogen for drinking water), averaginged 6.62 mg/L with maximum 28.95 mg/L. Groundwater types belonged to Mg-$HCO_3$, Na-$HCO_3$, Ca-$HCO_3$, and Na-Cl, among which Mg-$HCO_3$ type occupied more than 70% of the total samples, indicating the presence of anthropogenic sources. The concentration of nitrate nitrogen was negatively related to altitude and well depth, and positively related to the concentration of Ca, Mg, and $SO_4$ which might originate from chemical fertilizer. The ratio of nitrogen isotopes was estimated as an average of 8.10$^{\circ}/_{\circ\circ}$, and the maximum value of 17.9$^{\circ}/_{\circ\circ}$. According to the nitrogen isotope ratio, the most important nitrogen source was assessed as chemical fertilizer (52.6%) followed by sewage (26.3%) and livestock manures (21.1%).

• Horticultural Science & Technology
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• v.30 no.4
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• pp.392-399
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• 2012

This study was carried out to investigate the influence of molybden (Mo) concentrations in fertilizer solution on the growth of and nutrient uptake by domestically bred strawberries. Tissue analysis based on the dry weight was also conducted to determine the threshold levels in plants when Mo toxicity developed in strawberries. The leaf chlorophyll contents decreased lineally as Mo concentrations in the fertilizer solution were elevated. The differences among treatments in chlorophyll contents were statistically significant. The fresh and dry weights decreased significantly when the Mo concentrations in fertilizer solution were higher than 3.0 mM in 'Keumhyang' and 'Maehyang' strawberries and 1.0 mM in 'Seolhyang' strawberry. The elevation of Mo concentrations in fertilizer solution resulted in severe toxicity and crops developed the unique symptoms. The margin of older leaves became yellow and desiccated. Then, the margin of leaf blade rapidly became bronze colored and died as the symptoms spread up the plants. The interveinal area of the young leaves became yellowing. The elevation of Mo concentrations in fertilizer solution did not influence the tissue P, K, and Mg contents based on the dry weight. The tissue Ca contents were higher in 1.0 mM treatment than other treatments of 'Keumhyang' and 'Seolhyang' strawberries. The tissue Mo contents based on the dry weight of 'Keumhyang', 'Maehyang', and 'Seolyahng' strawberries were 76.5, 104.0, and 187.3 $mg{\cdot}kg^{-1}$, respectively, in the 0.25 mM treatments and 4,155, 5,367, and 2,190 $mg{\cdot}kg^{-1}$, respectively, in the 4.0 mM treatments. The contents increased lineally as Mo concentrations in fertilizer solution were elevated. When the concentration of Mo at which growth of crops were retarded by 10% is regarded as threshold level, the Mo contents based on dry weight of above ground plant tissue should be lower than 653.4, 686.2, and 589.7 $mg{\cdot}kg^{-1}$, in 'Keumhyang', 'Maehyang', and 'Seolyahng' strawberries, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.10
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• pp.667-671
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• 2014

By analyzing seed germination indexes of cabbage and radish, this study aims to evaluate the toxicity of food waste compost, which is produced by fermentation-extinction technology with bio wood chips. In the experimental results, the seed germination index of food waste compost for cabbage and radish was shown in the range of a minimum 104 and maximum 170. It was satisfied with the over 70 criteria in the level of the Korea fertilizer process specification. Consequently, the food waste compost from fermentation-extinction reaction with bio wood chips was evaluated by the appropriate compost maturity for the plantation.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1194-1202
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• 2012

Remotely sensed satellite images can be applied to monitor and obtain land surface information on inaccessible areas. We classified paddy field area in North Korea based on on-screen digitization with visual interpretation using 291 RapidEye satellite images covering the whole country. Criteria for paddy field classification based on RapidEye imagery acquired at different time of rice growth period was defined. Darker colored fields with regular shape in the images with false color composite from early May to late June were detected as rice fields. From early July to late September, it was hard to discriminate rice canopy from other type of vegetation including upland crops, grass, and forest in the image. Regular form of readjusted rice field in the plains and uniform texture when compared with surrounding vegetation. Paddy fields classified from RapidEye imagery were mapped and the areas were calculated by administrative district, province or city. Sixty six percent of paddy fields ($3,521km^2$) were distributed in the west coastal regions including Pyeongannam-do, Pyeonganbuk-do, and Hwanghaenam-do. The paddy field areas classified from RapidEye images showed less than 1% of difference from the paddy field areas of North Korea reported by FAO/WFP (Food and Agriculture Organization/World Food Programme).

• Journal of agriculture & life science
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• v.53 no.5
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• pp.153-165
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• 2019

This paper analyzes the priorities of introducing agricultural environmental conservation practices for the successful introduction of agricultural environmental conservation programs and promotes customized agricultural environment conservation practices packages suitable for the local environment. Agricultural environmental conservation practice consists of three fields: soil, water, and air, nine sub-fields, and 30 practice skills. Using the advantages of AHP and BWS appropriately for priority analysis, three areas and nine sub-fields are measured using AHP techniques, and the practical activities of each fields are measured by priorities using BWS techniques to enhance the differentiation and completeness of research. In addition, the criteria for evaluating priorities of practical activities used 'Environmental effectiveness' and 'Technical feasibility'. As a result of the priority evaluation, the 'Soil testing and reduction of fertilizer and livestock manure application' activities were evaluated as having the highest priority. Based on the results of the priorities for these practical activities, examples of customized practical activity packages by farming type and environmental conditions were presented.