• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.369-376
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• 2006

This research was conducted to evaluate the effect of root medium formulations on growth and nutrient uptake of hot pepper 'Knockgwang' in 72-cell plug trays. To achieve this, the nine root media were formulated by adjusting blending rate of perlite (PL) to coir (CO), peatmoss (PM) or coir+peatmoss (5:5, v/v, COPM). Then, the growth characteristics and tissue nutrient contents were determined at 35 and 70 days after sowing. The elevated blending rate of PL to CO increased fresh and dry weight of hot pepper at 35 days after sowing. The treatments of 20% in blending rate of PL to PM or that of 0% to COPM produced the highest fresh and dry weight among perlite treatments of PM or COPM. The results of crop growth at 70 days after sowing also showed similar trends to those of 35 days after sowing. The elevated blending rate of PL to CO or PM decreased tissue $P_2O_5$ and K contents and increased Ca and Mg contents at 35 days after sowing, With the equal blending rate of perlite, the plant tissue grown in CO had higher K contents and lower N, Ca and Mg contents than those in PM and COPM. The elevated blending rate of perlite in three organic matter also decreased tissue $P_2O_5$ and K contents at 70 days after sowing, but Ca and Mg contents were the highest in the treatment of 20% PL in CO, 40% PL in PM and 40% PL in COPM among perlite treatments in each organic matter.

• Journal of Soil and Groundwater Environment
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• v.22 no.5
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• pp.82-88
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• 2017

Contaminated sediment can be treated in order to reuse the treated sediment. Even though the chemical criteria are satisfied, the treated sediment could still impose toxic effects. Therefore, this study investigated the changes in the ecological toxic effects of the contaminated sediment from the J region in Singapore after treatment. The contaminated sediment was subject to sequential soil washing and thermal treatment, followed by pH neutralization. Toxic effects of the contaminated and treated sediments were determined by using Vibrio fischeri ($Microtox^{(R)}$), Triticum aestivum (wheat), and Eisenia foetida (earthworm). After treatment, the concentrations of total petroleum hydrocarbons and heavy metals were decreased by 98% and 59-93%, respectively, and satisfied the Industrial Maximum Values of the Dutch Standard, which were used as the remedial goal. The bioluminescence reduction of V. fischeri decreased significantly, and the earthworm survival increased from 0% to 90% after treatment. The germination rate increased from $0{\pm}0%$ to $75{\pm}13%$ after treatment, but the treated sediment may need additional treatment such as nutrient addition for better plant growth. Overall, this study showed that the treatment of the contaminated sediment satisfactorily removed mixed contaminants, and this led to reduction in toxic effects, suggesting improved potentials for reuse of the treated sediment.

• Journal of Biosystems Engineering
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• v.35 no.5
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• pp.343-349
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• 2010

Rapid on-site sensing of nitrate-nitrogen and potassium ions in hydroponic solution would increase the efficiency of nutrient use for greenhouse crops cultivated in closed hydroponic systems while reducing the potential for environmental pollution in water and soil. Ion-selective electrodes (ISEs) are a promising approach because of their small size, rapid response, and the ability to directly measure the analyte. The capabilities of the ISEs for sensing nitrate and potassium in hydroponic solution can be affected by the presence of other ions such as calcium, magnesium, sulfate, sodium, and chloride in the solution itself. This study was conducted to investigate the applicability of two ISEs consisting of TDDA-NPOE and valinomycin-DOS PVC membranes for quantitative determinations of $NO_3$-N and K in hydroponic solution. Nine hydroponic solutions were prepared by diluting highly concentrated paprika hydroponic solution to provide a concentration range of 3 to 400 mg/L for $NO_3$-N and K. Two of the calibration curves relating membrane response and nutrient concentration provided coefficients of determination ($R^2$) > 0.98 and standard errors of calibration (SEC) of < 3.79 mV. The use of the direct potentiometry method, in conjunction with an one-point EMF compensation technique, was feasible for measuring $NO_3$-N and K in paprika hydroponic solution due to almost 1:1 relationships and high coefficients of determination ($R^2$ > 0.97) between the levels of $NO_3$-N and K obtained with the ion-selective electrodes and standard instruments. However, even though there were strong linear relationships ($R^2$ > 0.94) between the $NO_3$-N and K concentrations determined by the Gran's plot-based multiple standard addition method and by standard instruments, hydroponic $NO_3$-N concentrations measured with the ISEs, on average, were about 10% higher than those obtained with the automated analyzer whereas the K ISE predicted about 59% lower K than did the ICP spectrometer, probably due to no compensation for a difference between actual and expected concentrations of standard solutions directly prepared.

• Journal of Korea Foresty Energy
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• v.23 no.1
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• pp.1-18
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• 2004

Effects of nitrogen and phosphorus fertilization on aboveground biomass and distribution of nutrient content in tree components were determined in adjacent 41-year-old plantations of Pinus rigida Miller and Larix kaempferi Gordon on a similar soil in Yangpyeong, Gyeonggi Province. Fertilizer was experimentally applied at the three levels [control(C), 200 N kg/ha+25 P kg/ha(LNP), and 400 N kg/ha+50 P kg/ha(HNP)] in June, 1996. The results obtained from this study were summarized as follows: Total aboveground biomass of P. rigida and L. kaempferi stands was 149, 145ton/ha for control, 166, 149ton/ha for LNP, and 152, 170ton/ha for HNP, respectively, and did not differ between the tree species. Aboveground biomass of P. rigida and L. kaempferi plantations were distributed as follows: stemwood>branch>stembark>foliage. Biomass of understory vegetation was 1,111kg/ha for P. rigida and 907kg/ha for L. kaempferi, and comprised 0.6～0.7% of the total aboveground biomass of the plantations. The concentrations of all nutrients(N, P, K, Ca, Mg) were generally higher in L. kaempferi than in P. rigida because of high nutrient uptake characteristics of Larix spp. Nutrient concentrations in tree components of P. rigida and L. kaempferi plantations were not significantly different among treatments, whereas they were significantly different between species and among tree components. The nutrient concentration in tree components of both tree species decreased in order of foliage>branch>stembark>stemwood. The contents of all nutrients were higher in the fertilized plots than in the control plots, generally the highest in LNP for P. rigida and in HNP for L. kaempferi. Total nutrient(N+P+K+Ca+Mg) contents of aboveground biomass were 703kg/ha for P. rigida and 869kg/ha for L. kaempferi, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.4
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• pp.249-254
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• 2007

Inoculation dose of agriculturally important microbes is an important criterion that decides the establishment and hence their effects on plant growth. Effects of the inoculation dose of Azospirillum brasilense strain CW903 on the growth and nutrient absorption of three different crops, tomato, rice and red pepper were assessed under green house condition. Three different concentrations of A. brasilense strain CW903 ($10^5$, $10^6$ and $10^8cfu\;mL^{-1}$) were applied through seed treatment and through the soil near the root zone (1 mL per plant) at 20 and 30 days after sowing. Positive effects on the growth of tomato, rice and red pepper were found at $10^6$ and $10^8cfu\;mL^{-1}$ inoculation doses of A. brasilense strain CW903. The inoculation dose of $10^8cfu\;mL^{-1}$ of A. brasilense strain CW903 recorded the best effects on growth parameters like shoot and root length and the absorption of important nutrients.

• Korean Journal of Organic Agriculture
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• v.20 no.3
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• pp.357-368
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• 2012

This study was conducted to evaluate soil inorganic N concentrations and N uptake efficiency of sorghum ${\times}$ sudangrass hybrid (Sorghum bicolor (L.) Moench) as affected by organic nutrient sources from 2009 to 2011. The treatments included chemical fertilizer, compost, oilcake, alfalfa hay mulch, and control. Nutrient applications were made at rates equivalent to approximately 210 kg of actual N per hectare. The precipitation during the growth period from May to September was higher in 2011, followed by 2009, and 2010. Oilcake had the lowest C:N ratio in the raw materials. Compost treatment slowed N-mineralization rate in soil during the measured years. Soil mineral nutrition and dry matter production were not consistently affected by treatments, but the dry matter production was negatively correlated with the amount of precipitation from May to September for three years. Chemical fertilizer treatment increased N efficiency in plants in the first two years, observing with lower N efficiency in plants treated with compost for 3 years. Increased precipitation from June to August improved N efficiency in sudangrass plants treated with compost but reduced the efficiency with the chemical fertilizer. Total dry matter production and N efficiency in plants were not affected by the C:N ratio of the raw materials rather than weather condition.

• Korean Journal of Environmental Agriculture
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• v.17 no.2
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• pp.182-188
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• 1998

The effect of arbuscular mycorrhizae(AM) on the growth of trifoliate orange seeding were investigated in volcanic ash soil. Trifoliate orange is used as a root stock of citrus in Cheju island. Seedings innoculated with AM fungi were grown for 16 weeks in pots of various levels of fertilizer. Growth characteristics and mineral nutrient contents were measured and spores of AM fungi colonized were identified. Seventy % of the replicsted pots of seedings were colonized by AM in the treatment of high level fertilizer and additional phosphate (40g of 21-17-17 complex fertilizer and 50g of fused phosphate added to 50L of soil). In treatments of low levels fertilizer or without fused phosphate addition, the pots colonized were less than 20 %. Colonization of trifoliate seedings with AM fungi greatly increased the growth of seedings. Shoot length and weight of shoot and root positively regressed on AM colonization ratio. AM colonization caused higher concentrations of P, Cu and Mg in plant, and the relations were significant at 5 % level. Contents of N and Zn in plants also tended to increase, while that of Ca to decrease, with increasing colonization ratio. Four species of AM fungi - Glomus deserticola, G. rubiforme, G. vesiculiferum and Acaulospora sp, - were found in the soil where roots of trifoliate orange as an innoculation materials were collected. All of the 4 species were found in the inoculated pot soils after the seedling growth, indicating that these species can be colonized in trifoliate orange roots.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.3
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• pp.55-64
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• 2023

This batch experiment was conducted to investigate the patterns of major plant nutrients in the leachates from the soil that was incorporated with rice hull biochar adjusted pH with dry fish powder utilizing rice hull biochar for loading the soil microorganisms. The rice hull biochar adjusted pH between 6.0 and 7.0, and the mixture ratio of rice hull biochar and dry fish powder was 4:6. The treatments consisted of three; the soil incorporated with rice hull biochar non-adjusted pH with dry fish powder as control (RB + DF), the soil incorporated with rice hull biochar adjusted pH by pyroligneous acid solution and dry fish powder (RBP+DF), and the soil incorporated with rice hull biochar adjusted pH by citric acid solution and dry fish powder (RBC+DF). NH₄-N, NO₃-N, PO₄-P, and K concentrations in the leachates were analyzed during incubation. The accumulated NH₄-N and PO₄-P concentrations in the leachates from the RBC+DF treatment were the highest during leaching periods. The highest accumulated NO₃-N and K concentrations in the leachates from the RBP+DF treatment were observed. It observed that NH₄-N and PO₄-P were more released in the adjusted citric acid solution, but NO₃-N and K were less released than those in the pyroligneous acid solution due to their low absorption capacity. Furthermore, it is necessary to investigate crop growth responses to the soil incorporated with adjusted pH rice hull biochar and dry fish powder for loading soil microorganisms.

• Journal of Ecology and Environment
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• v.36 no.1
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• pp.31-38
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• 2013

Annual ring formation is considered a source of information to investigate the effects of environmental changes caused by temperature, air pollution, and acid rain on tree growth. A comparative investigation of annual ring growth of Cryptomeria japonica in relation to environmental changes was conducted at two sites in southern Korea (Haenam and Jangseong). Three wood disks from each site were collected from stems at breast height and annual ring growth was analyzed. Annual ring area at two sites increased over time (p > 0.05). Tree ring growth rate in Jangseong was higher than that in Haenam. Annual ring area increment in Jangseong was more strongly correlated with environmental variables than that in Haenam; annual ring growth increased with increasing temperature (p < 0.01) and a positive effect of $NO_2$ concentration on annual ring area (p < 0.05) could be attributed to nitrogen deposition in Jangseong. The correlation of annual ring growth increased with decreasing $SO_2$ and $CO_2$ concentrations (p < 0.01) in Jangseong. Variation in annual growth rings in Jangseong could be associated with temperature changes and N deposition. In Haenam, annual ring growth was correlated with $SO_2$ concentration (p < 0.01), and there was a negative relationship between precipitation pH and annual ring area (p < 0.01) which may reflect changes in nutrient cycles due to the acid rain. Therefore, the combined effects of increased $CO_2$, N deposition, and temperature on tree ring growth in Jangseong may be linked to soil acidification in this forest ecosystem. The interactions between air pollution ($SO_2$) and precipitation pH in Haenam may affect tree growth and may change nutrient cycles in this site. These results suggested that annual tree ring growth in Jangseong was more correlated with environmental variables than that in Haenam. However, the further growth of C. japonica forest at two sites is at risk from the long-term effects of acid deposition from fossil fuel combustion.

• Korean Journal of Organic Agriculture
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• v.18 no.2
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• pp.245-255
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• 2010

The study was conducted to investigate the effects of organic fertilizers and mulches on the growth and $CO_2$ assimilation in MM.106 apple trees. Growth and $CO_2$ assimilation of MM.106 apple trees grown in a greenhouse were affected by the nutrient concentrations and carbon (C) and nitrogen (N) ratio in the raw materials of organic fertilizers and mulches. The optimum C:N ratios, which makes microorganism convert the organic N into the inorganic N, were obtained in the organic fertilizer, poultry litter, green compost, and grass clippings, resulting in increasing single shoot height, SPAD, and $CO_2$ assimilation. The SPAD and $CO_2$ assimilation were affected by the treatments 5 weeks after the treatments, and then the tree growth was affected by the treatments 6 weeks later. The most efficient tree growth and development were observed in the 10 to $15\;mg{\cdot}kg^{-1}$ of the inorganic N in a soil, and the N was strongly related to the tree growth and development.