• Membrane and Water Treatment
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• v.10 no.1
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• pp.83-89
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• 2019

The most common way of reducing non-point source pollutants from agricultural areas is the installation of reservoirs. However, this method is only effective for surface runoff of settleable pollutants. This study was conducted to estimate the effect of interflow, baseflow, and surface runoff on pollutant runoff in a small agricultural catchment. Runoff of organic matters, SS, and T-P were directly proportional to the rainfall variation, while ammonia and nitrate were inversely proportional to the amount of rainfall. The interflow and baseflow was only 46% of the total stream flow, but the nitrate load reached 78%. The interflow as a nutrient transport pathway should be considered for managing a stream water quality. It requires careful attention and appropriate control methodology such as vegetation to consider the influence by interflow. The reservoir as a dry extended detention pond (DEDP) has function of nutrient captor.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.4
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• pp.275-280
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• 2007

This experiment was conducted to investigate the selection of regional double cropping system for production of organic forage in middle part of Korea. The species of forage crop used in this experiment were corn, $sorghum\;{\times}\;sudangrass$ hybrid and japanese millet for summer crops and rye and Italian ryegrass for winter crops. $Sorghum\;{\times}\;sudangrass$ hybrid showed higher DM (dry matter) and TDN (total digestible nutrient) yield than that of corn. Dry matter yield of corn decreased to 56% that of control because of weed. In winter crops, DM and TDN yield of rye is higher than that of Italian ryegrass. Rye was more adequate to produce organic forage in middle part of Korea. We could not find out the difference of nutrient value between each treatments. It means that the amount of nutrient is affected by DM productivity of each crop. The result of this study indicated that $sorghum{\times}sudangrass$ hybrid (summer crop) and rye (winter crop) cropping system could be recommended as producing high yield of organic forage in middle part of Korea.

• Korean Journal of Organic Agriculture
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• v.27 no.2
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• pp.205-224
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• 2019

This study was carried out in order to evaluate the growth promotion effects on tomato crops and to assess the mineral nutrient concentrations of farm-made liquid fertilizers used in organic cultivation in South Korea. We hope that this study will help to develop of a standardized manufacturing technique for these organic liquid fertilizers. We collected 62 farm-made liquid fertilizers made from various raw materials including fish, seaweed, food scraps, plant and crop by-products, and other materials. Two groups of tomato seedlings were treated at different times, one at 20 days and the other at 40 days after sowing. We used both foliar and soil applications. These seedlings were treated using liquid fertilizers at various dilution rates (x1000, x500 and x100). When foliar application was used, seedlings after 20 days had a 20-30% increase in shoot fresh weight with 47-48 fertilizers and seedlings after 40 days had a 20-30% increase in shoot fresh weight with 17-32 fertilizers. When soil application was used, seedlings after 20 days had the same increase in shoot fresh weight with 30-31 fertilizers and seedlings after 40 days also saw the same increase with 6-7 fertilizers. Therefore, our studies showed that application of liquid fertilizers to seedlings 20 days after sowing was most effective and that foliar treatment was more effective than soil treatments. We also observed that the higher the concentrations of fertilizer, particularly when applied twice rather than just once, the higher the rates of growth, which promoted shoot fresh weight more than plant height. Our results imply that mineral nutrients in liquid fertilizers seem to be the probable cause for the growth promotion observed in this study. However, more study is required to determine exactly which mineral nutrients are most effective.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.3 s.26
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• pp.165-170
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• 2006

In this study, organic matters production was calculated with long term data in Wando costal area where was selected for non influent of fresh water. The objective of this study was to evaluate relationship between nutrients and phytoplankton and, between phytoplankton and organic matter. The result of DIN was the highest with 0.138 mg/L in winter season and the lowest with 0.052 mg/L in summer season. Similarly, DIP was shown to be 0. 017 mg/L in winter and 0.011 mg/L in summer. Limiting nutrient was revealed with nitrogen in Wando costal area. Specially in summer season, nitrogen limitation was the greatest with 10.5 of N/P ratio. Chl. -a was increased 80%, 108% in spring and summer compare with winter. COD was the lowest with 0.84 mg/L in winter and the highest with 1.10 mg/L in summer. The interrelation between nutrients and Chl. -a was high. Relationship $coefficient(r^2)$ were 0.93(P<0.05), 0.89(P <0.05) between DIN and Chi. -a, DIP and Chl. -a. This results suggest dissolved nutrients might be utilized at the production of phytoplankton. Also Relationship $coefficient(r^2)$ was 0.77(P<0.05) between Chl. -a and COD. COD production rate was calculated with regression equation. The COD production rate was 17% in winter and 36% in summer. It was revealed nutrients were decreased according to temperature increasing and then Phytoplankton and organic matter were increased. The Relationship of Nutrients, Chl. -a and COD was very high.

• Korean Journal of Organic Agriculture
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• v.23 no.3
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• pp.509-522
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• 2015

Organic ginseng farming has rapidly increased in response to consumer demand for a safe product which improves health. Differences in soil nutrient concentration and ginsenoside content between organic and conventional ginseng farming have, however, not yet been properly studied. Therefore the aim of the present study was to compare soil nutrient concentration and ginsenoside content between these two farming systems. $NO_3-N$, $P_2O_5$, and K were significantly different between organic and conventional ginseng farming. The total content of ginsenoside and individual ginsenoside components were higher in organically grown ginseng than in ginseng from conventional farming, although there is no significant difference. Particularly, protopanaxadiol saponins were higher than protopanaxatriol saponins in ginseng from organic farming compared to ginseng produced by conventional farming. $NO_3-N$ content in soils showed a negative correlation with the content of ginsenosides $Rb_2$ and Rd. In addition, $P_2O_5$ showed a negative correlation with ginsenosides $Rb_1$, Rc, and PD/PT ratio. Organic matter showed a positive crrelation with ginsenosides Re. To increase the ginsenoside content of ginseng, we recommend increasing organic matter and decreasing $NO_3-N$ and $P_2O_5$ contents in the soil.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.4
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• pp.232-242
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• 2014

We investigated the interspecific competition between the harmful dinoflagellate Cochlodinium polykrikoides and diatom Skeletonema sp. based on the utilization and uptake of dissolved organic nutrients. C. polykrikoides and S. costatum were able to grow using dissolved organic nitrogen (DON) and dissolved organic phosphorus (DOP) as well as dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP). This result indicates that the utilization of dissolved organic nutrients may play a role in surviving strategy in the DIN or DIP-limited environments. The half-saturation constants (Ks) of urea and glycerophosphate (glycero-P) calculated from uptake kinetics experiment of C. polykrikoides was lower than those of Skeletonema sp. This result indicates that Skeletonema sp. have higher affinity for dissolved organic nutrients, such as urea and glycero-P, than C. polykrikoides. Although Skeletonema sp. have higher affinity of dissolved organic nutrients, C. polykrikoides could effectively uptake for urea and glycero-P at sub-saturating nutrient concentrations (${\alpha}$ (${\rho}_{max}/Ks$) of C. polykrikoides was higher than Skeletonema sp.. Therefore, C. polykrikoides by utilization and effectively uptake of dissolved organic nutrients under monoculture may have an advantageous position in the interspecific competition with Skeletonema sp. in the low nutrient environments.

• Journal of Ecology and Environment
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• v.41 no.10
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• pp.281-289
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• 2017

Background: In this study, the growth and reproductive response of seedlings, grown in plastic pots with sand, to moisture and nutrients were analyzed in order to study the environmental conditions required to create an alternative habitat for Epilobium hirsutum L., an endangered plant. Results: Vegetative and reproductive growths of Epilobium hirsutum L. are accelerated with increase in moisture and organic matter content in the soil. Among vegetative organs, the number of runners related to asexual reproduction was the highest when the moisture content was over 25% and nutrient content between 7 and 14% in the soil. But the number of flowers related to flowering responses, among reproductive organs, was the highest when the moisture content was maintained at 75% and when nutrient content was 21% in the soil. The number of seeds, related to sexual reproduction, was the highest when the moisture content was over 25% and nutrient content between 14 and 21%. Conclusions: The study results show that a place with high moisture and nutrient content in the soil is advantageous to asexual and sexual reproduction of Epilobium hirsutum L. Therefore, we must serve periodically nutrient and seeds to sustain population in in situ conservation. Furthermore, it is advisable to create in riverside where abundant nutrient content have, making alternative habitat of Epilobium hirsutum L. Also, we must find species that have high contribution degree index through vegetation survey.

• Journal of Forest and Environmental Science
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• v.29 no.1
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• pp.29-37
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• 2013

The study was carried out in two different forest types viz., Banj oak and Chir pine forests to assess the variation in forest species composition and soil properties along altitudinal gradients in the Garhwal Himalayas. The results of the study showed that between the forests soil moisture was higher in Banj oak forest because of closed canopy and dense forest compared to Chir pine forest. The sand particles were reported higher in Banj oak forest which might be due to the addition of organic matter favouring coarse structure of soil, helping in holding maximum water in soils. However in the Chir pine forest low amount of soil organic matter and presence of clayey soil, develops soil compactness which reduces the penetration of water resulting in high soil bulk density. The higher accumulation of litter and presence of moisture in Banj oak forest favours higher nutrient level of nitrogen, phosphorus and potassium compared to Chir pine forest. The soil organic carbon also reduced with increasing altitude at both gradients. While bulk density has reverse trend with soil organic carbon in both the forests at different peaks of same region. In Banj oak forest, the highest density and total basal cover was reported 1,100 tree $ha^{-1}$ and 58.86 $m^2\;ha^{-1}$ respectively. However, the highest values of density and total basal cover of Chir pine forest was 560 tree$ha^{-1}$ and 56.94 $m^2\;ha^{-1}$ respectively. The total density and basal cover of both the forests reduced with increasing altitude. The study concludes that Banj oak forest has better nutrient cycling ability, well developed foest floor and has a greater protective and productive features compared to the Chir pine forest which is without lower vegetation cover and having only pine litter accumulation which does not allow any other species to grow.

• Korean Journal of Organic Agriculture
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• v.13 no.2
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• pp.211-221
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• 2005

This experiment was conducted to evaluate the effect of animal slurry on nitrogen uptake of hairy vetch and growth of chinese cabbage in cropping system. Hairy vetch was seeded on September 20 in 2003 . We examined the effect of cover crop(hairy vetch (Vicia villosa Roth) and slurry application(0, l00, 200kg N/ha) on yield and N uptake. Dry matter yield and nitrogen uptake of hairy vetch were measured. The chinese cabbage succeeding cover crop was harvested in 2004. The nitrogen uptake of hairy vetch was 84, 121, 148kg N/ha respectively, when the slurry application was 0, 100 and 200kg N/ha. In addition. N uptake of hairy vetch at the plot of 100kg and 200 kg N/ha slurry were 44% and 76% higher than that of the plot without slurry application respectively. Slurry application of hairy vetch could increase nitrogen uptake by application of green manure at the harvesting time. the content of organic matter and P-content of soil with hairy vetch plot was higher than that of fallow plot due to inhibition of soil erosion. The organic matter levels tend to improve with the addition of hairy vetch. Hairy vetch could improve soil quality by reducing erosion compared with bare fallow. The green manure of hairy vetch with animal slurry maintained soil nutrient and reduced nitrogen fertilizer of chinese cabbage. The hairy vetch residues decomposed rapidly releasing half of their residues within 40 days after burial. The yield of chinese cabbage was 90% in the plot of manure of hairy vetch compared with chemical fertilizer. The yield in the plot treated with green manure of hairy vetch and 50% of chemical fertilizer was reduced 5% less than that of chemical fertilizer. Therefore, it was estimated that the green manure of hairy vetch-chinese cabbage cropping system could reduce nitrogen chemical fertilizer as much as 84~148kgN/ha. the green manure of hairy vetch with animal slurry maintained soil nutrient and reduced nitrogen fertilizer of chinese cabbage.

• Journal of Environmental Science International
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• v.8 no.5
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• pp.617-623
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• 1999

This study was carried out to obtain the optimal operating parameter on organic matters and nutrient removal of mixed wastewater which was composed of sewage and stable wastewater using SBR. A laboratory scale SBR was operated with An/Ae(Anaerobic/Aerobic) ratio of 3/3, 2/4 and 4/2(3.5/2.5) at organic loading rate of 0.14 to 0.27 kgBOD/$m^3$/d. TCOD/SCOD ratio of mixed wastewater was 3, so the important operating factor depended upon the resolving the particulate parts of wastewater. Conclusions of this study were as follows: 1) For mixed wastewater, BOD and COD removal efficiencies were 93-96% and 85-89%, respectively. It was not related to each organic loading rate, whereas depended on An/Ae ratio. During Anarobic period, the amount of SCOD consumption was very little, because ICOD in influent was converted to SCOD by hydrolysis of insoluble matter. 2) T-N removal efficiencies of mixed wastewater were 55-62% for Exp. 1, 66-76% for Exp. 2, and 67-81% for Exp. 3, respectively. It was found that nitrification rate was increased according to organic concentration in influent increased. Therefore, the nitrification rate seemed to be achieved by heterotrophs. During anoxic period, denitrification rate depended on SCOD concentration in aerobic period and thus, was not resulted by endogenous denitrification. However, the amount of denitrification during anaerobic period were 3.5-14.1 mg/cycle, and that of BOD consumed were 10-40 mg/cycle. 3) For P removal of mixed wastewater, EBPR appeared only Mode 3($3^＊$). It was found that the time in which ICOD was converted to VFA should be sufficient. For mode 3 in each Exp., P removal efficiencies were 74, 87, and 81%, respectively. But for 45-48 of COD/TP ratio in influent, P concentration in effluent was over 1 mg/L. It was caused to a large amount of ICOD in influent. However, as P concnetration in influent was increased, the amounts of P release and uptake were increased linearly.