• The Journal of Natural Sciences
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• v.13 no.1
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• pp.83-96
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• 2003

Effect of Nutrient Concentrations, fertigation frequency, and learching percentage on crop growth and nutrient concentrations in root media were evaluated. The treatment of each irrigation with $50 mg.L^{-1}$ of nitrogen in stage 2 and increase to $80 mg.L^{-1}$ nitrogen in stage 3 had the highest crop growth at 34 days after sowing among treatments tested. Feeding with low nutrient concentrations and elevated frequency decreased crop growth. In treatments of each leaching percentage, feeding with low nutrient concentrations and elevated frequency resulted in increased tissue nutrient contents. The less tissue potassium content and higher calcium and magnesium contents were observed in treatment of 50% leach than those in 0% leach. All treatment tested had soil solution pH higher than 6.8. Electrical conductivity in treatments of 50% leach were lower than those of 0% leach. Feeding with low nutrient concentrations and elevated feeding frequency in each leaching percentage resulted in increased electrical conductivity in soil solution of root media. Trends of medium nutrient concentrations were similar to those of electrical conductivity.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.101-110
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• 2004

The growth and niche breath of four species, i.e., native plants such as Bidens tripauita and B. bipinnata and naturalized plants such as B. frondosa and B. pilosa var. minor, were studied as related with environmental gradients including light intensity, soil moisture and soil nutrient. There were no significant differences in the phonology within each environmental gradients while considerable differences were found between species; the two naturalized species bloomed and produced fruit later than the two native species. Two naturalized species exhibited relatively higher total dry weight than the two native counterparts within all environmental gradients. Total dry weight showed positive responses to light intensity and soil moisture, and negatively to soil nutrient. The relative contribution of the environmental factors to total dry weight decreased in the order of soil nutrient, soil moisture and light intensity. Both B. bipinnata and B. pilosa var. minor showed significantly higher net assimilation rate (NAR) than other species. Also, NARs of B. bipinnata and B. pilosa var. minor decreased with increasing soil nutrient. Relative growth rate (RGR) decreased in order of B. tripartita, B. bipinnata, B. frondosa and B. pilosa var. minor in response to light intensity. In addition, RGRs of B. bipinnata and B. piEosa yay. minor increased in response to soil moisture, while those of B. pilosa var. minor and B. tripartita decreased with increment of soil nutrient. No significant fluctuations of shoot/root ratio were not observed in three species, but a native species, B. tripartita showed n decreased shoot/root ratio in response to soil nutrient. Comparing the growth characteristics of the species, B. pitosa var. minor and 3. tripartita revealed vigorous growth on barren soil. On the other hand, B. frondosa exhibited vigorous growth on fertile soil. Morphologically, B. tripartita adapted to light and required considerable moisture. On the contrary, the leaves of B. bipinnata did not change considerably in their area, although it preferred habitat with abundant light. In terms of niche breadth, B. bipinnata showed the widest ranges of 0.875 and 0.845 for light intensity and soil moisture gradients, respectively. B. pilosa var. minor showed a value of 0.933 for soil nutrient gradient. B. tripartita showed narrow ranges for the three environmental factors, whereas B. frondosa showed wide values for light intensity and soil nutrient, but relatively narrow value for soil moisture.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.452-457
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• 2013

To obtain the useful data related to optimum nutrient management technique for pesticides-free jujube cultivation, nutrient contents of jujube leaves and fruits and the selected chemical properties of jujube orchard soils were investigated at 9 different orchards with pesticides-free cultivation in Boeun, Chungbuk, Korea. Soil and jujube leaf samples were collected from the different orchards in July and October, and jujube fruit samples were taken in October, 2012. Soil available $P_2O_5$ contents in the optimum level for jujube cultivation were 11% and 33% of total samples in July and October, respectively, but 56% of total samples was higher than the optimum level in both July and October. Exchangeable K and Ca ion contents were 44% and 67% of total samples, respectively, in both July and October, whereas exchangeable Mg ion content was 100% and 56% of total samples in July and October, respectively. Nutrient contents in jujube leaves were higher than those in fresh fruits. In addition, total nitrate, potassium and magnesium contents in the jujube leaves were higher in the samples collected in July than in October.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.83-89
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• 2010

We investigated the growth of cucumber plants, the uptake and use of mineral nutrients, such as $NO_3$-N, $NH_4$-N, $K^+$, $Ca^{+}^{+}$, $Mg^{+}^{+}$ and $Na^+$, absorbed from media solution, and the synthesis and distribution of soluble sugars under nutrient-deficient condition. Difference in plant growth revealed after 20 days of treatment. Nitrate uptake in nutrient-deficient condition was significantly reduced compared with nutrient-normal treatment, and its distribution was primarily in petioles, stem, roots and less in leaves. In contrast, ammonium content was markedly predominated in fast growing organs, and it was significantly different in growing leaves, expanded leaves, and roots under similar growth conditions. $K^+$, lack by deficient nutrient condition, was found in growing leaves. The $Ca^{+}^{+}$ content did not show significant difference between treatments and a substantial portion of $Ca^{+}^{+}$ remained in petioles. The $Mg^{+}^{+}$ content was significantly higher in the leaves of nutrient-normal condition compared with nutrient-deficient condition while significantly lower in stem and roots. The behavior of $Na^+$ in plant was similar to $K^+$ although its content was relatively little. The highest $CO_2$ assimilation was observed in fully expanded leaves of nutrient-normal condition, which was 1.7 times higher compared with nutrient-deficient condition. The instantaneous water use efficiency (A/E) and the A/gsratio, which is an index of leaf intrinsic water use efficiency for individual leaves, was 1.2 and 1.1 times higher, respectively. The total soluble sugar (TSS) contents were highest in leaves followed by petioles, stems and roots, and in younger leaves. The growing leaves contained about 7,200 mg $kg^{-1}$ of TSS in nutrient-normal condition whereas the TSS contents in nutrient-deficient condition were not significantly different between leaves. The $Mg^{+}^{+}$ and $NH_4$- N were positively correlated with the TSS whereas $NO_3$ - N was negatively correlated.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.6
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• pp.582-587
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• 2015

This study was conducted to compare the plant growth and fruit quality of blueberries grown in different soil textures of Korea, in order to utilize the results for stable production and soil improvement. Rabbiteye blueberry cultivars 'Tifblue' and 'Baldwin' were planted and grown for three years from 2013 in wagner pot (1 $2000a^{-1}$) in a greenhouse of Namhae Sub-station, Institute of Horticultural and Herbal Science. The plants were grown in four soil textures, sand, sandy loam, loam and silt loam, and nutrient uptake and growth characteristics of plants were investigated. Leaf nitrogen and phosphorus contents of two cultivars grown in different soil textures ranged between 8.6 to $10.5gkg^{-1}$, which was lower than appropriate level for rabbiteye blueberry. However, the contents of potassium, calcium and magnesium in leaves were appropriate levels as $2.29{\sim}3.62gkg^{-1}$, $4.46{\sim}5.46gkg^{-1}$ and $1.45{\sim}2.12gkg^{-1}$, respectively. Nitrogen and phosphate contents in leaves were higher in the two cultivars grown in silt loam soil. There was no significant difference in plant volume and root dry weight among four soil textures in two cultivars. However, dry weight of leaves and branches were highest in loam soil. Fruit production was highest in loam and silt loam soil in two cultivars, showing negative correlation with the amount of sand in soil. However, sugar and acidity showed no correlation with sand content in soil. These results show the limit to the blueberry growth in soil that has no nutrient holding capacity; however, most of Korean soils that have good nutrient holding capacity can produce competitive fruits if the drainage is improved.

• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.871-879
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• 2022

An increasing global population requires a greater food supply, and accordingly there is demand for enhanced production of rice, as a major crop plant that covers half of the world's population. Rice production in arid area is extremely difficult due to poor soil fertility, salinity, deficit of irrigation water, and weather conditions. The aim of the present study was to determine whether various fertilization recipes could provide a countermeasure to allow rice production while also providing soil amendment such as soil pH adjustment. The study was conducted at an experimental field of the United Arab-Emirates (UAE) from January to April, 2022. Rice seedlings (cv. Asemi, alkaline-resistant) were transplanted in plastic containers, and different types of water and nutrient managements were employed as follows: water management (flooding and aerobic for NPKs treatment group) and nutrient management (NPKs, slow release fertilizers [SRFs] and SRFs + NPK-1 treatment groups with flooding). Water and nutrient management did not show any effect on soil pH adjustment. Rice growth was significantly enhanced in the flooding compared to the aerobic condition, whereas the effect of nutrient management clearly differed among the treatment groups, with SRFs + NPK-1 showing the best results followed by SRFs and NPKs. Most of the fertilization groups markedly accumulated soluble sugars in the shoots and grains of rice plants, but concomitantly a decrease in the roots. Overall, the level of starch showed a tendency of relatively slight perturbation by fertilization. Taken together, the results indicate that soil physical structure should be preferentially amended to find the key for suitable rice production.

• Journal of Korean Society of Forest Science
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• v.111 no.1
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• pp.108-114
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• 2022

In bamboo, the nutrient status of tissues and associated soil is an important indicator of nutrient uptake by various bamboo species. In this study, the nutrient concentrations of leaves, roots, and mineral soil at 0-10 cm depths were examined in three bamboo stands [Phyllostachys bambusoides S ieb. et Zucc, Phyllostachys nigra var. henonis Stapf ex. Rendle, and Phyllostachys pubescens (Mazel) Ohwi] at a broad regional scale in southern Korea. In the three bamboo species, species-specific differences were observed in the carbon (C) and calcium (Ca) concentrations of leaves and in the nitrogen (N) and magnesium (Mg) concentrations of roots. Ca concentrations in leaves were significantly higher in P. bambusoides (11.94 g Ca kg^-1) than in P. pubescens (7.83 g Ca kg^-1), whereas potassium (K) concentrations were lowest in P. bambusoides among the three bamboo species. N concentrations in the roots were significantly lower in P. pubescens (5.23 g N kg^-1) than in P. nigra var. henonis (7.72 g N kg^-1). In contrast to bamboo tissues, soil nutrients, such as total N, organic C, exchangeable Ca²⁺, and Mg²⁺, did not differ significantly among the bamboo species. These results suggest that species-specific practices will be required for nutrient management of bamboo stands because nutrient concentrations vary considerably in the tissues of the three studied species.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.2
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• pp.164-170
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• 2005

The amounts and nutrient compositions in precipitation, throughfall, stemflow and soil solution of natural deciduous forests (Quercus variabilis and Q. mongolica) were examined in Gwangju, Gyeonggi Province. The proportion to gross precipitation was $85\%$ for throughfall, $2-6\%$ for stem flow, $53-54\%$ for Ao horizon soil solution, $23-30\%$ for A horizon soil solution, and $11-14\%$$ for B horizon soil solution, respectively. pH and K concentration increased in throughfall and only K concentration increased in stemflow. Canopy leaching appeared to influence these changes. pH, and Ca and Mg concentrations increased significantly in the Ao horizon soil solution, and Ca concentration was higher in the B horizon than in the A horizon. However, there were no significant differences in pH and other nutrient concentrations between A and B horizons. Litter decomposition and leaching from Ao horizon might explain the changes. K, Mg and Cl concentrations in throughfall and soil solution decreased with precipitation. Nutrient contents increased in the transports from precipitation, through throughfall, to Ao horizon soil solution, while they decreased in the transport from A to B horizon soil solution. Stemflow contained less than $10\%$ of total (throughfall plus stemflow) nutrient contents.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1137-1143
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• 2011

Optimum soil management of chestnut orchards is important to ensure high quality and yields of chestnut. This study was conducted to evaluate soil and green leaf characteristics by establishment periods of chestnut (Castanea crenata Sieb. et. Zucc.) orchards in Sancheong-gun, Gyeongsangnam-do. Total 30 plots with the criteria of similar cultivation practices were chosen and classified into two establishment periods by over 20-year-old orchards (17 plots) and below 19-year-old orchards (13 plots). Soil bulk density was significantly higher (p<0.05) in over 20-year-old ($1.16g\;cm^{-3}$) than in below 19-year-old ($1.03g\;cm^{-3}$) plots. Soils in over 20-year-old plots were severely acidified with pH 4.56 compared to pH 4.73 in below 19-year-old plots. However, soil organic matter, total nitrogen, available phosphorus, and potassium were not significantly different (p>0.05) between both establishment periods. Leaf area, leaf mass, and nutrient (N, P, K, Ca, Mg) concentration of green leaves were also not significantly different (p>0.05) between both establishment periods. The results indicate that soil bulk density in chestnut orchards is dependent on the establishment periods, while soil chemical property and leaf nutrient concentration may be little influenced by the establishment periods.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.2
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• pp.115-122
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• 1999

Investigation of nutrient movement in soil and soil water is necessary to clarify water purification functions and nutrient circulation within a forest ecosystem. In this study, seasonal changes in the nutrient content of soil and soil water was investigated in Korean white pine(Pinus koraiensis) and Japanese larch(Larix leptolepis) forest applied urea ($150kg\;ha^{-1}$). Soil pH was decreased rapidly in Japanese larch plot for a long period. On the other hand, soil pH was increased slightly in Korean white pine plot. T-C and T-N content were increased in both plots. In Japanes larch plot, exchangeable Ca and Mg contents were decreased remarkably than those in korean white pine plot while exchangeable K was increased rapidly after application. The effect of urea application on exchangeable K was not obvious compared to other cations. The pH, Ca, $NH_4-N$, $NO_3-N$, $SO_4-S$ and Cl concentrations in the sampled soil water at surface soil were increased only temporarily after fertilization, with the only exception of the decrease in pH of the soil water in Japanese larch plot. On the other hand, the peak value of K, Mg concentrations in the soil water was shown between 2 and 5 months after fertilization. The concentrations of Ca, $NO_3-N$, $SO_4-S$ and Cl returned to the values found before fertilization after about 1 month. Those of K, Mg, and $NO_3-N$ after 6-12 months.