• Korean Journal of Soil Science and Fertilizer
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• v.46 no.3
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• pp.216-222
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• 2013

Fertilizer management has the potential to promote the storage of carbon and nitrogen in agricultural soils and thus may contribute to crop sustainability and mitigation of global warming. In this study, the effects of fertilizer practices [no fertilizer (Control), chemical fertilizer (NPK), Compost, and chemical fertilizer plus compost] on soil total carbon (TC) and total nitrogen (TN) contents in inner soil profiles of paddy soil at 0-60 cm depth were examined by using long-term field experimental site at $42^{nd}$ years after installation. TC and TN concentrations of the treatments which included N input (NPK, Compost, NPK+Compost) in plow layer (0-15 cm) ranged from 19.0 to 26.4 g $kg^{-1}$ and 2.15 to 2.53 g $kg^{-1}$, respectively. Compared with control treatment, SOC (soil organic C) and TN concentrations were increased by 24.1 and 31.0%, 57.6 and 49.7%, and 72.2 and 54.5% for NPK, Compost, and NPK+Compost, respectively. However, long term fertilization significantly influenced TC concentration and pools to 30 cm depth. TC and TN pools for NPK, Compost, NPK+Compost in 0-30 cm depth ranged from 44.8 to 56.8 Mg $ha^{-1}$ and 5.78 to 6.49 Mg $ha^{-1}$, respectively. TC and TN pools were greater by 10.5 and 21.4%, 30.3 and 29.6%, and 39.9 and 36.3% in N input treatments (NPK, Compost, NPK+Compost) than in control treatment. These resulted from the formation and stability of aggregate in paddy soil with continuous mono rice cultivation. Therefore, fertilization practice could contribute to the storage of C and N in paddy soil, especially, organic amendments with chemical fertilizers may be alternative practices to sequester carbon and nitrogen in agricultural soil.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.1
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• pp.72-88
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• 2006

The optimal environmental ranges of the establishment phase for the distribution of Zizania latifolia and Typha angustifolia was determined to develop a set of basic data and criteria of planting substrate for the restoration, conservation and management of wetlands. The study was carried at 17 wetlands in the Kyunggi-do and Gyeongsangnam-do region where inland wetlands place intensively in June, 2005. Total 127 quadrats were sets in growing areas of Zizania latifolia and Typha angustifolia. $NO_3-N$, K, Ca, Mg and Na in the water variables and soil texture, LOI (loss on ignition), soil pH and soil conductivity in the soil variables were analyzed. The optimal range of water depth for the distribution of Zizania latifolia was -5~39cm, $NO_3-N$ content of water was <0.01~0.19ppm, K content of water was 0.1~5.9ppm, Ca content of water 0.5~44.9ppm, Mg content of water was 1.2~11.9ppm, Na content of water 3.4~29.9ppm, water conductivity was 48~450${\mu}S$/cm, respectively. The optimal range of LOI for the distribution of Zizania latifolia was 1.7~11.9%, soil conductivity was 25.5~149.9${\mu}S$/cm, respectively. The optimal range of water depth for the distribution of Typha angustifolia was -20~24cm, $NO_3-N$ content of water was <0.01~0.19ppm, K content of water was 0.2~2.9ppm, Ca content of water 0.6~19.9ppm, Mg content of water was 0.2~5.9ppm, Na content of water 3.5~19.9ppm, water conductivity was 96~450${\mu}S$/cm, respectively. The optimal range of LOI for the distribution of Typha angustifolia was 2.4~15.9%, soil conductivity was 17.6~149.9${\mu}S$/cm, respectively. The optimal soil texture were loam, silt loam and sandy loam in both species. The lower water depth (-20~40cm) is appropriate to increase biodiversity in both species dominated community and it is better to maintain water depth of 40~100cm for water purification. Both species appear frequently in the soil with high silt content.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.6
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• pp.534-540
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• 1992

Climatic condition and seeding depth affect the seedling stand and early growth in the direct-seeded rice cultivation on dry soil. This experiment was conducted to elucidate the effects of the day /night temperatures and the seeding depths on the seedling emergence and mesocotyl elongation of rice seed. Three combinations of the day/night temperatures(25/2$0^{\circ}C$ 20/15$^{\circ}C$ and 20/1$0^{\circ}C$) were employed with seeding depths 1, 3, 5 and 7cm at the Phytotron of the Crop Experiment Station in 1991. It appeared that seedling emergence ratio increased and days to seedling emergence decreased in the high temperature (25/2$0^{\circ}C$) and the deep seeding depth (5 and 7cm) condition. The seedling emergence ratio did not. show the, difference up . to the seeding depths of 3cm and below, but the ratio decreased from the seeding depths of 5cm and above. Plant height and leaf number were almost the same up to the depths of 3cm at 30 days after seeding, but those of the seeding depths of 5cm and 7cm were remarkably reduced in all temperature combinations. Mesocotyl and lower internode elongation were seen in the high temperature(25/2$0^{\circ}C$) with the seeding depths of 5cm and 7cm. In the seeding depth of 6cm, of the tested varieties, Tamjinbyeo and Odaebyeo showed the highest emergence ratio. Generally, leaves of all tested varieties appeared approximately in the soil depth of 3cm, so the reasonable seeding depth will be around 3cm in the direct-seeded cultivation on dry soil.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.2
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• pp.99-104
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• 2013

Vegetables production in greenhouse are typically intensely managed with high inputs of fertilizers and irrigation water, which increases the risk of ground-water nitrate contamination. In 2010 and 2011, a study was conducted to determine the appropriate depth of soil moisture sensor for automatic irrigation control to use water and nitrogen efficiently under subsurface drip irrigation (SDI) systems. The irrigation line for SDI placed 30 cm below soil surface and tensiometer was used as soil moisture sensor. Three tensiometer treatments placed at 10 (SDI-T10), 20 (SDI-T20) and 30 cm (SDI-T30) depths below soil surface under SDI. These are also compared to SUR-T20 treatment where tensiometer placed at 20 cm below soil surface under surface drip irrigation (SUR) systems. The growth of cucumber was not statistically different between SUR and SDI without SDI-T30 treatment. Fruit yields (Mg/ha) were 57.0 and 56.9 (SDI-T10), 56.0 and 60.5 (SDI-T20), 40.9 and 41.2 (SDI-T30) and 56.6 and 54.3 (SUR-T20) for 2010 and 2011, respectively. Slightly higher total yield was observed in tensiometer placed 20 cm below the soil surface, although no significant differences were found between SDI-T10 and SDI-T20 under SDI treatments. In addition, nitrogen application rates and daily irrigation rates were lowest in SDI-T20 compared with other SDIs and SUR treatments. Nitrogen and daily irrigation application under SDI-T20 was lower than that under SUR-T20 by 6.0%. These findings suggested tensiometer 20 cm depth under SDI systems was best for cucumber production in greenhouse.

• Journal of Korean Society of Forest Science
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• v.100 no.3
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• pp.476-482
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• 2011

As part of studies on the reduction of forest trails degradation caused by high users density, this study was carried out to investigate soil physical properties of forest trails of Gyeongnam Domain in Mt. Jiri, Southeast Korea. Since the forest were opened for leisure trailing in 2008, the average soil erosion amounts per a square meter on the forest trails were $0.0015m^3$ from Inweol to Gumgeo, $0.0018m^3$ from Dongang to Suchol, and $0.0027m^3$ from Suchol to Chungam for 3 years. But, from Chungam to Agyang, the erosion was almost not occurred because it was recently opened. The soil hardness in 5 cm depth was significantly higher than in 10 cm depth. It indicates that intensive soil compaction by users has mainly affected in 5 cm soil depth until now on. In three forest trails compacted intensively, the porosity of 0-7.5 cm soil layer was down to 1.4-1.5 times compared to that in 2008. In additions, the bulk density was up to 1.6-3.1 times compared to the controls, which were not opened to users. As a result, the degradation caused by high users density would keep occurring on the three forest trails unless any counterplans are considered for the degradation reduction. At the moment, users distribution to other forest trails and long-term sabbatical years would be the most effective counterplans to keep from users gravitation on the three forest trails.

• Journal of Soil and Groundwater Environment
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• v.7 no.3
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• pp.71-77
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• 2002

This research was carried out from 2001. 4 until 2001. 5 in order to examine the level of soil contamination in the vicinity of Nanjido. The sampling was done at near the Nanjido soil. At the each sampling site we did the sampling at different depth- surface(0~15cm deep), 1m deep, 2m deep, 3m deep. The contamination of Cd, Cu, Pb, As, $Cr^{+6}$, and Hg were tasted and analysed by spectra AA. The examination showed that the average concentration level of the entire sampled soil was Cd, 0.229mg/kg, Cu 8.349mg/kg, Pb : 11.083mg/kg, As : 0.298mg/kg, $Cr^{+6}$ : 0.124mg/kg, and Hg : 0.134mg/kg. The concentration level of at the depth of 0-l5cm, came out to be Cd : 0.305mg/kg, Cu : 8.464mg/kg, Pb : 11 383mg/kg, As : 0.128mg/kg, $Cr^{+6}$ : 0.153mg/kg, and Hg : 0.092mg/kg. It shows that in the cases of Cd and C $r^{+6}$ the average concentration level of the whole sampled soil was about 80% of that of 0-l5cm depth. And as for Hg and As. the average concentration level of the entire sampled soil came out to be approximately twice as high as the sample soil from the depth surface, As for Cu and Pb, there was not much difference between the entire samples average concentration level and the concentration level of surface. It was hard to find much relationship between the depth of each site where sampling was done and the level of concentration, the concentration level of Pb and Cu at the sampling site C and E was quite high, which suggests that it has been affected by the polluted the hyang-dong stream and fill random up waste.

• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.48-53
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• 1998

The purpose of this study was to compare heavy metal concentrations in uncontaminated soil with those in soil influenced by industrial activities, and to investigate the relationship between change of heavy metal content and the kind of industry at the Iksan 1st Industrial Complex that has started since 1975. Soils sampled in 0-3㎝ and 3-6㎝ soil depth, respectively were analized for content of Cd, Cu, Ni, Pb and Zn. Change of heavy metal content in soil of the industrial complex were more accumulated 16 to 25% of Cd and Cu, 93% of Pb and Zn, respectively in samples compared with natural soil uncontaminated. But there was no different in Ni content between two soil. Distribution of Cd in soil layer of 0 to 3cm was the highest concentration of 5 ppm more at the textile industries, and then higher at the chemicals and the food processing industries. In 3 to 6㎝ soil layer Cd content was the highest concentration of 5 ppm more at the metal processing industries, and then higher at the textile industries. Cd accumulation in soil was different according to a kind of industry and soil depth. Cu content was the highest value of 400 ppm more in soil layer of 0 to 3cm at the manufacturing electric wires industry area and showed the accumulation phenomenon in soil layer 3 to 6cm at the ohmmeter, machines and electric wires industry area. Ni content was 35 ppm more in soil of the metal plating and processing industries regardless of soil sampling layer. Then it was 25 ppm more in soil of the building stones and semiconductor industries. Pb content was from 400 to 1000 ppm in soil of the chemicals and textiles industries regardless of soil sampling layer. Zn content was 1200 ppm more in soil of the chemicals and silk fabrics industries regardless of soil depth, and then lower in order to soil of leather processing${\le}$metal plating industries. In conclusion, changes of heavy metal kinds and content in soil of this industrial complex area were caused by the type or kinds of industrial activities. Changes of Pb and Zn content in soil were dominated at this area.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.1
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• pp.112-118
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• 1997

This study was conducted to obtain basic information on the desalinization in newly reclaimed tideland. A desalinization experiment with leaching method was carried out using the soil samples collected in Haenam tideland, and the early growth response of winter barley to salt stress during the desalinization was investigated by measuring emergence rate, plant height, leaf area and fresh weight. The soil in Haenam tideland was saline-sodic with 59mS / cm of electrical conductivity and pH 8.0, and the soil texture was silty loam with 16％ clay and 75％ silt. Depth of water for desalinization(DWD) to decrease the electrical conductivity below 4mS /cm was 140mm in 5cm depth soil and 240mm in 20cm depth soil. The value of pH of soil and leaching water increased from 8.0 to 8.3 until the electrical conductivity decreased to about 6mS / cm during the desalinization. .The emergence rate of winter barley was over 75％ in the DWD above 80mm and showed no significant difference with the DWD. The DWD for the normal growth of winter barley seedling was above 120mm at 1 and 2 weeks after sowing(WAS), and above 160mm at 3 and 4 WAS. The leaf area and fresh weight showed no response for salt stress with the DWD above 12mm at 2 WAS, and above 16mm at 3 WAS. It was estimated that the electrical conductivity of soil saturation extract for the normal growth of winter barley during early seedling growth stage in new reclaimed tideland would be below 9mS / cm in 20cm depth soil.

• Journal of Environmental Science International
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• v.21 no.3
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• pp.289-296
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• 2012

The purpose of this study was to identify the irrigation intervals and the amount of suitable growing substrate needed to achieve the desired shallow-extensive green roof system during a dry summer in Korea. In terms of treatment, three types (SL, $P_6P_2L_2$, $P_4P_4L_2$) with varying soil mixture ratios and two types (15 cm, 25 cm) with varying soil depths were created. The results have been analyzed after measuring growth and soil water contents. The difference of growth by treatment was significant in terms of green coverage, height, leaf width and photosynthesis. In measurement of chlorophyll content, no difference was detected when measured against soil depth. According to the growth measurement of Zoysia japonica with respect to differing soil mixture ratios in the 15 cm-deep treatment, a statistical difference was detected at the 0.05 significance level in photosynthesis. In case of green coverage, height, chlorophyll content and leaf width, no statistical significance was observed. In case of the 25 cm-deep treatment, a statistical significance was observed in height and photosynthesis. In terms of green coverage, chlorophyll content and leaf width, no statistical significance was detected. In comparisons of soil moisture tension and soil water contents, the irrigation interval and amount were 8 days and 14.9 L in the SL (15 cm) treatment, respectively. The irrigation interval showed for 10 days a 1.3-fold increase, and the irrigation amount was 27.4 L 1.8-fold more than SL (25 cm), respectively. For $P_6P_2L_2$ (15 cm) treatment, the irrigation interval and amount were 12 days and 20.7 L, respectively. However, an irrigation interval under $P_6P_2L_2$ (25 cm) was for 15 days 1.3 times longer than $P_6P_2L_2$ (15 cm), and an irrigation amount of 40 L was 1.9 times more than that under $P_6P_2L_2$ (15 cm). In $P_4P_4L_2$ (15 cm) treatment, it was indicated that the irrigation interval was 15 days, and the irrigation amount was 19.2 L. It was not needed to irrigate for 16 days under $P_4P_4L_2$ (25 cm) treatment during the dry summer and the longest no-rain periods. The irrigation interval and amount under $P_4P_4L_2$ were 1.8-fold and 1.3-fold, respectively, more than SL treatment as affected by soil mixture ratio. Comparatively $P_4P_4L_2$ had more 1.3-fold and 0.9-fold in irrigation interval and amount more than $P_6P_2L_2$. Therefore, it can be noted that different soil depth and soil mixture ratios had a significant effect on the irrigation interval and amount.

• Analytical Science and Technology
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• v.10 no.2
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• pp.105-113
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• 1997

We investigated the content of heavy metals contained in the soil at an Il-Kwang disused mine in Kyung Nam. Three sampling points were selected, each point was digged to 210 or 240cm, sampled each 30cm depth. After air drying, each sample was digested in aqua regia and then analyzed with an Inductively Coupled Plasma Atomic Emission Spectrometer. We determined the content of Zn, Pb, Cr, Cd, Cu, Mn, and Fe, maximum content of Pb, Cd, and Zn was observed to $(4.6{\pm}0.1){\times}10^3$, 9.4(${\pm}3.6$), and $(2.7{\pm}0.1){\times}10^2{\mu}g/g$ respectively. Mean pH values of soil sampled at No.1, 2, and 3 regions were 3.2, 2.6, and 2.8, respectively. These values are remarkably lower than pH of the conventional standard soil which usually shows pH level around 4.9. At each sampling point, maximum content of heavy metals was observed from 30cm to 60cm depth. The depth profiles of Zn, Cd, Pb, and Cr showed very similar tendencies to each other, but those of Fe, Cu. and Mn showed different tendencies to former ones.