• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.268-272
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• 2013

BACKGROUND: The mixtures of legumes and non legumes can be an efficient tool to combine the benefit of the single species in the cover crop practice. However, there is a lack of information on how the species proportion may affect N accumulation and how this can influence the nitrogen use of subsequent rice production. METHODS AND RESULTS: In this study barley and hairy vetch was selected as a green manure. The pure stands or mixtures with different seeding ratios was tested on green manure N accumulation and its following rice cultivation. Total aboveground biomass and N accumulation of mixture were higher compared to that of pure barley and hairy vetch. Among the mixtures, the highest aboveground biomass (8.07 Mg/ha) and N accumulation (131 kg/ha) was observed in B75H25 (barley 75% + hairy vetch 25%). The N accumulation of the mixture ranged from 99 kg/ha to 131 kg/ha which was much higher than amount of recommended (90 kg/ha) for rice. All mixture (barley 75%+hairy vetch 25%, barley 50%+hairy vetch 50%, barley 25%+hairy vetch 50%) produced 7-8% more rice yield than the conventional cultivation (NPK). The rice yield of in barley monocrop was 4% less than that of NPK. COLCLUSION(S): Adopting mixtures of barley and hairy vetch could be efficient strategy for rice production as an alternative of nitrogen fertilizer.

• The Journal of Engineering Geology
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• v.13 no.1
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• pp.83-105
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• 2003

Geochemical studies on the alluvial aquifer system near the Nakdong River were carried out for the basic investigation of the estimation of artificial recharge for the river bank filtration. In-situ data do not show any distinct difference between the pumping well and river. Most of waters belong to $_3$ and Ca-$SO_4$ types and show high Mn concentration. In the borehole installed with Multi-Ca-HCOPacker (MP) system, Na, Ca, Mg, $HCO_3$ contents of the groundwater are increased with depth increasing. Cl and $SO_4$ contents of the groundwater show the lowest values at the bottom level (18m depth) and Mn content is very high at the middle level (13.5 m depth) of MP system. There is no distinct difference in the ${\delta}^{18}O$ and D values and tritium content between MP, borehole and surface water samples. The sulfur isotope data indicate that the possible sulfur source is dissolution of sulfate mineral from sedimentary rock. Strontium isotope ratio shows a little differences between the pumping well and observation borehole samples. Nitrogen isotope data indicate that the nitrogen of water samples is originated from fertilizer or organic materials.

• The Korean Journal of Ecology
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• v.27 no.4
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• pp.199-210
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• 2004

Effects of nitrogen and phosphorus fertilization on seasonal changes of nutrient content in tree components, and retranslocation N and P in foliage and twig were determined in adjacent 41-year-old plantations of Pinus rigida Miller and Larix kaempferi Gordon on a similar soil in Yangpyeong, Gyeonggi Province. In general, foliage N and P concentrations of L kaempferi were significantly higher than current and 1-year-old foliages of P. rigida. N and P concentrations were higher in foliage than in twigs for both tree species. However, there were no significant differences in foliage and twig N and P concentrations with ages. Significant seasonal differences in foliage and twig N and P concentrations were observed for both tree species because of nutrient retranslocation. Foliage nutrient concentrations were highest in the mid-growing season and lowest in autumn, whereas twig nutrient concnetrations have gradually increased since July. These seasonal trends indicated nutrient retranslocation from foliage into twigs before foliage senescence. However, there were no significant changes in foliage and twig nutrient retranslocation, and no consistent patterns in foliage and twig nutrient retranslocation following N and P fertilizer additions. No significant changes in nutrient retranslocation between different foliage and twig ages were observed following fertilization.

• Horticultural Science & Technology
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• v.35 no.4
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• pp.431-438
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• 2017

This study investigated the effect of pre-planting nitrogen (N) fertilization levels added to a soilless root medium on the growth of 'Dotaerang Dia' tomato seedlings. The N levels were varied for a total of 7 treatments: 0, 100, 250, 500, 750, 1,000, or $1,500mg{\cdot}L^{-1}$. The pH of the root media gradually rose in all treatments as the seedlings grew; however, the differences in the pH were not significant among the treatments. The electrical conductivity (EC) of the root media was significantly different among the treatments from sowing to week three, then drastically decreased after week four, which diminished the differences in the EC among the treatments. At week six, plant height, leaf length, leaf width, number of leaves, and fresh and dry weights of the shoot were highest for the treatment with $500mg{\cdot}L^{-1}N$. In contrast, the treatment with $1,500mg{\cdot}L^{-1}N$ had the lowest results for all growth measurements. The fresh weight was 67% heavier in the $500mg{\cdot}L^{-1}N$ treatment compared to the $1,500mg{\cdot}L^{-1}N$ treatment. The total N content in the tissues was lowest in the treatment with $0mg{\cdot}L^{-1}N$ and highest in the treatment with $1,000mg{\cdot}L^{-1}N$. The contents of calcium (Ca), magnesium (Mg), and metal micronutrients in the tissues were highest in the $250mg{\cdot}L^{-1}N$ treatment. A previous study demonstrated that adjusting the fertilization level to promote growth to over 90% of the maximum growth is a good strategy for lowering production costs and preventing damage due to excessive fertilizer absorption by crops. Our results indicated that the optimal pre-planting N fertilization level for tomato plug seedlings should be lower than $500mg{\cdot}L^{-1}$ and the optimum tissue N contents should be around 3.21% to 4.60%.

• Korean Journal of Medicinal Crop Science
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• v.12 no.6
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• pp.454-458
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• 2004

This study was carried out to clarify the effect of sulfur fertilization method on the qualities of safflower (Carthamus tinctorious L.) seed. Sulfur application increased the nitrogen and sulfur content of seed. In nitrogen content, there was no significant difference among sulfur fertilizers, whereas sulfur content was increased by raising ammonium sulfate (AS) amounts by soil application. In application method of AS, there was no significantly difference between foliar application and soil application with 8 kg S/10a. N/S ratio in seed was decreased by sulfur application, and also decreased with the increase of AS amounts by soil application. The contents of lipid and protein were increased by sulfur application. Lipid content was highest in foliar application, and protein content was lowest in AS 4 kg S/10a. By sulfur application, the content of total phenolics and electron donating ability (EDA) were increased by $3.1{\sim}4.7%$ and $3.6{\sim}8.5%$, respectively compared with control. In content of total phenolics, there was no significant difference among sulfur fertilizers, but EDA was higher in sulfur powder 20 kg/10a and AS 8 kg S/10a than that in other fertilizers. Sulfur application showed positive effects on the qualities of safflower seed. In application effects, AS and foliar application were more efficient than sulfur powder and soil application, respectively.

• Journal of the Korean Society of Tobacco Science
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• v.10 no.1
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• pp.11-19
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• 1988

This study was conducted to relate among growth characteristics, quality, and chemical components for flue-cored tobacco. The results are summarized as follows : 1. Starch content in harvested green leaf was correlated negatively with leaf length, leaf width, leaf area, and leaf weight of harvested green leaf, respectively, while positively with total sugar content in cured leaf, and the ratio of leaf length to leaf width of harvested green leaf. 2. Organic matter and total nitrogen contents in the soil were correlated positively with nicotine content in cured leaf, respectively, and total nitrogen in the soil negatively with total sugar content in cured leaf. 3, Amount of fertilizer, application date of MH, priod of harvesting, and yield were correlated positively with nicotine content in cured leaf, respectively , while negatively with total sugar content. Application amount of MH was correlated positively with total sugar content, but negatively with nicotine content in cured leaf. Also amount of compost was correlated negatively with nicotine content in cured leaf. 4. The ratio of total sugar to nicotine (TS/N) per plant was correlated positively with price (Won/kg) and specific leaf area, but negatively with leaf length. leaf width, leaf area, harvested leaves, and leaf weight in cured leaves, respectively. Yield was correlated negatively with TS/N per plant. 5. TS/N of the best quality tobacco per plant was 12.0. Those of the best quality tobacco in each stalk position were 42.1 for first~third leaf, 28.4 for 4th~6th leaf , 23.7 for 7th~9th leaf, 7.7 for l0th~12th leaf , and 7.8 for over 13th leaf from bottom, respectively. 6, When TS/N was 12.0, optimum values of growth characteristics per plant were 100.5 $\pm$ 10.3g for leaf dry weight, 755.1$\pm$53.2cm for leaf length, 294.4$\pm$25.1cm for leaf width, 8, 892$\pm$111cm2 for leaf area, 16.0$\pm$0.6 leaves for harvested leaves, and 7.32$\pm$0.44mg/cm2 for specific leaf area, respectively. 7. When TS/N was 12.0, optimum values of chemical components per plant were 1.92$\pm$0.28% for nicotine content, and 20.4$\pm$ 1.4 % for total sugar content, and that of yield was 238.3$\pm$ 9.8kg/10a.

• Korean Journal of Environmental Agriculture
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• v.18 no.1
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• pp.70-76
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• 1999

Since high concentrations of N, P, and organic C cause the excessive eutrophication in water systems, the control of nutrient export from agricultural nonpoint sources has become important. This study was conducted to estimate discharges of N, P, and organic C from a small agricultural watershed of the upper Imgo stream in Youngchun, Kyongbuk. Of the total area(1.420ha), 25% was agricultural land including paddy, upland and orchards and most of the remainder was forest. The resident population in the watershed was 194 in 80 households and relatively small numbers of livestocks including cow were raised. Mean concentrations of nutrients in the stream water were 4.95, 0.80, 6.72, 0.07 and 2.52mg/L for $NO_3-N$, $NH_4-N$, Total N, Total P and COD respectively. Annual discharges in 1997 were 28,991kg of $NO_3-N$. 3,010kg of $NH_4-N$, 37,006kg of Total N. 590kg of Total P, and 29,138kg of COD. There was a strong positive relationship between stream flow and precipitation, and also most of the nutrient discharges occurred in the rainy season (May to August). Since there was no any other industries in the watershed, agricultural practices and sewage from the resident households, forest runoff and livestock wastes were the major sources of NPS discharges. A combination of management options, including management of soil erosion and fertilizer application, could lead to reductions in nutrient exports.

• Korean Journal of Environmental Agriculture
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• v.17 no.4
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• pp.352-357
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• 1998

This experiment was conducted to find out the effects of major nutrient levels(N, P, K) on ozone susceptibility of tomato plants(Lycopersicon esculentum Mill, cv. Pink Glory). Plants were grown in water culture system. A half-strength of Hoagland's nutrient solution was considered as a standard formulation($N_{100}$ $P_{100}$ $K_{100}$). The levels of major nutrients were adjusted through addition or removal of several fertilizer salts from the standard solution. Top growth was significantly decreased at the low nitrogen level or phosphorus removal condition. P- and K-contents of leaves were greatly decreased by removal of salts containing P and K from the nutrient solution. The rate of ozone injury was significantly increased when potassium was removed. However, the influence of nitrogen and phosphorus levels or high potassium level on injury occurrence did not show statistical significance compared to the standard solution. Ozone exposure resulted in reduction of chlorophyll, and increase of ethylene production, electrolyte leakage and malondialdehyde(MDA) contents. These changes were much more enhanced in plants grown at the potassium removal solution. Whereas the activity of superoxide dismutase(SOD) was low at the potassium removal treatment and this tendency remained after ozone exposure. These results indicated that potassium nutrient level in tomato plants is closely associated with the susceptibility to ozone injury.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.1
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• pp.75-86
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• 2002

This study was performed to investigate situation of livestock manure generated from Kangwon-do and to evaluate its composting probability. The scale of livesrock-farming is bigger and bigger in Korea. Regulation based on the heads of livestock is slightly different from that based on livestock-farming household. So it is needed ro evaluate regulations for livestock head and livestock-farming household. Composting and liquid fertilization were thought to be appropriate technologies to the trearment of Korean cattle and pig manures, respectively. Generation quantity of pig manure was the greatest among pig, Korean cattle, cow and chicken manures. Pig manure generated the greatest amounts of BOD in Kangwon-do. Pig manure contained nitrogen, Korean cattle manure contained $K_2O$, and chicken and pig manures contained $P_2O_5$ in great amount. Alternative ratio of livestock manure to crops-fertilizer was 51% for nitrogen, 38% for $K_2O$, and 34% for $P_2O_5$.

• Korean journal of applied entomology
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• v.21 no.1 s.50
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• pp.27-33
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• 1982

Thytealexin activities were investigated in compatible and incompatible combinations between rice cultivars and races of Pyricularia oryzae by using the spore-germination test in the diffusates from surface of leaf-blade treated with the spore suspensions. In compatible and incompatible combinations between nine cultivars of rice and three races of the fungus, phytoalexin activities were recognized in all combinations, and were much higher in incompatible combinations than in compatible combinations with significant differences. Activities of phytoalexin were increased with the time, and maximal peaks of them were at 36 hours after inoculation, and thereafter decreased. The activities were generally decreased in all combination by heavy applications of nitrogen fertilizer, especially in incompatible combinations. On the other hand, fresh juices from leaves of rice cultivars which were not inoculated with the fungus showed no phytoalexin activities.