• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.407-414
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• 2007

In order to evaluate the physicochemical properties of sludge compost and to identify the effects water-extracts from sludge compost in 2, 6, 8, 12 weeks of decomposing process on seed germination and root elongation in cabbage, lettuce, soybean and barley plants was investigated. The content of total nitrogen in sludge compost increased slightly in 6 weeks decomposing process, and then decreased gradually. Organic matter content decreased continuously overall decomposing process. As decomposition was processing, pH of sludge compost decreased slightly, and EC increase within 6 weeks decomposing process, and then decreased. The content of nitrogen in water-extracts from sludge compost increased within 8 weeks decomposing process and decreased in 12 weeks decomposing process. The content of ammonium nitrogen was similar with that of total nitrogen, and the ratio of ammonium and nitrate increased within 8 weeks, and then decreased. Cation content and EC decreased the late of decomposing process and pH didn't change. The water-extracts from sludge compost during decomposing process inhibited seed germination and root elongation in cabbage (Brassica campestris), lettuce (Lactuca sativa), barley (Hordeum vulgare) and soybean (Glycine max). The inhibition of root elongation in cabbage was greater than that of relative seed germination, whereas relative seed germination in lettuce was more inhibit than root elongation. Relative seed germination and root elongation in soybean were inhibited slightly, but those of in barley was inhibited strongly. In this study, we would identify the effects of water-extracts from sludge compost on seed germination and root elongation was different to the species of seed. The inhibition of seed germination and root elongation treated with the water-extracts which extracted from sludge compost in the early stage of decomposing process was greater than that of in the late stage of decomposing process.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.293-303
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• 2017

To elucidate the physiological responses of rice plants to the essential mineral silicon (Si), we assessed the effects of treatments with Si, nitrogen ($NH_4NO_3$; ammonium nitrate), and calcium ($CaCl_2$; calcium chloride), independently or in combination on mineral uptake rates and levels of the hormones abscisic acid (ABA), gibberellin ($GA_1$) and jasmonic acid (JA). We found that nitrogen and calcium uptake was inhibited by Si application. However, solo application of nitrogen or calcium did not affect Si uptake. Compared to the untreated plants, the application of Si, $NH_4NO_3$ or $CaCl_2$ increased the endogenous hormone levels in treated plants. In particular, the concentrations of $GA_1$ and JA increased significantly after the application of Si or $NH_4NO_3$. The level of $GA_1$ observed after a treatment (solo or combine) with Si, and $NH_4NO_3$ was higher than that of the control. By contrast, independent application of $CaCl_2$ or a combined treatment with Si and $CaCl_2$ did not alter $GA_1$ levels. The highest level of $GA_1$ was present in plants given a combination treatment of Si and $NH_4NO_3$. This effect was observed at all time points (6 h, 12 h and 24 h). Endogenous JA contents were higher in all treatments than the control. In particular, a combination treatment with Si and $NH_4NO_3$ significantly increased the JA levels in plants compared to other treatments at all time points. A small increase in JA levels was observed after 6 h in plants given the $CaCl_2$ treatment. However, JA levels did not differ between plants given a $CaCl_2$ treatment and controls after 12 h or 24 h of exposure. We conclude that treatment with $CaCl_2$ alone does not affect endogenous JA levels in the short term. Endogenous ABA contents did not show any differences among the various treatments.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.460-467
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• 2022

The purpose of this study is to enhance utilization of the waste nutrient solution (WNS) disposed at the hydroponic greenhouse. Several sets of testing were conducted to examine the effects of WNS: (a) a fertilizer effect, (b) soil column leaching, and (c) crop cultivation. The fertilizer effect test was applied in young radish cultivation by examining the growth characteristics of young radish and soil based on inorganic nitrogen according to the soil treatment of the nitrogen fertilizer (NF) and the WNS. The fertilizer effects and crop cultivation test were conducted with five treatments (A-E): A, non-treatment (water); B, 100% of NF; C, 70% of NF + 30% of WNS; D, 50% of NF + 50% of WNS; and E, 30% of NF + 70% of WNS. The soil column leaching test was conducted with three treatments: non-treatment (water), 100% of NF, 50% of WNS + 50% of NF. As a result, the chemical properties of the WNS were pH 6.0, EC 2.4dS·m^-1, total phosphorus (T-P) 28mg·L^-1, ammonium nitrogen (NH₄-N) 5.0mg·L^-1, and nitrate nitrogen (NO₃-N) 301mg·L^-1. The chemical properties of the soil were pH 5.51, EC 0.31dS/m, organic matter 2.08g·kg^-1, NO₃-N 9.64mg·kg^-1, and NH₄-N 3.20mg·kg^-1. The results of fertilizer effects showed that the ratio of 50% or less of NF and 50% or more of WNS was high in young radish growth. There was no statistically significant difference between the soil chemistry in the C-E treatments where WNS was mixed with NF and the B treatment where only NF was applied. As a result of the soil column leaching test, there was no significant difference in the concentrations of NO₃ and NH₄ in the treatment of 100% of NF and 50% of NF + 50% of WNS. The study indicates, if the mixed fertilizer of WNS and NF is applied in the soil cultivation of young radish, it will reduce the use of NF and environmental pollution. This also helps reduce production costs on farmers and increase the yield of young radish.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.4
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• pp.225-233
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• 1978

Uptake and distribution of labelled urea, $NH{_4}^+$, and $NO{_3}^-$ by Tongil and Jinheung rice grown with each nitrogen source until ear formation stage under water culture system were as follows. 1. When the previous nitrogen source was same as one tested the uptake rate ($mg^{15}N/g$ d.w. root 2hrs, at $28^{\circ}C$ light) was great in the order of $NH_4$ >urea> $NO_3$ and higher (especially $NH_4$) in Tongil than in Jinheung. Rate limiting step (slowest) seems to be exist at R (root)${\rightarrow}$LS(leaf sheath) for urea, LS${\rightarrow}$LB(leaf blade) for $NH_4$ and M(medium)${\rightarrow}$R for $NO_3$. The fast step of translocation appeare to be at M${\rightarrow}$R for urea R${\rightarrow}$LS for $NH_4$ and LS${\rightarrow}$LB for $NO_3$. 2. The uptake rate of $NH_4$ by the urea-fed plant increased almost linearly from $18^{\circ}C$ via $28^{\circ}C$ to $38^{\circ}C$ in Tongil ($Q_{10}$=1.21 and 1.32 respectively) while no change in Jinheung ($Q_{10}$=0.99 and 1.00 respectively). It decreased by 12% in Jinheung under dark but uo change in Tongil. 3. The uptake rate of nitrogen source by different source-fed plant was great in the order of $NH_4{\rightarrow}^{15}NO_3$ $NO_3{\rightarrow}^{15}NH_4$, $urea{\rightarrow}^{15}NO_3$ and higher (especially $NH_4{\rightarrow}^{15}NO_3$) in Tongil. In the case of $urea{\rightarrow}^{15}NH_4$ it was same in $NH_4{\rightarrow}^{15}NO_3$ for Tongil and slightly lower than that in $NO_3{\rightarrow}^{15}NH_4$ for Jinheung. It was lower (especially Tongil) in $NH_4{\rightarrow}^{15}NO_3$ than in $NH_4{\rightarrow}^{15}NH_4 $ 4. The uptake rate (in $NH_4{\rightarrow}^{15}NO_3$) was higher during 15 minutes than during 2 hours and always higher in Tongil. 5. $^{15}N$ excess % and content in each part, and uptake rate of root seems to have their own significance relatling with metabolism and translocation respectively. The change of nitrogen nutritional environment and source preference of varieties were discussed in relation to field condition and efficient use of nitrogen fertilizer.

• Applied Biological Chemistry
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• v.11
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• pp.151-166
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• 1969

I. Fffects of nitrogen supplying level and culture condition on the top growth aod tubers formation of Ipomoea Batatas. 1) The low level nitrogen (A plot) 3 Milliequivalent per liter of nutrient solution stimulated tuber formation while the high level nitrogen ($B_1\;and\;B_2$ plot) of 10 milliequivalent per liter failed to form tuber though fibrous roots were seen much activated. The suppressive effect of nitrogen on tuber formation in presumed to result from the direct suppressive effect of nitrogen or a certain biocatalystic effect rather than from any indirect effect through the stimulation to growth of tops or the competition with carbohydrates. 2) The addition of milligram urea to nutrient solution stimulated the growth and increased fresh weight and dry weight of the aerial part while suppressed, a little, plant length. 3) The water culture method, which this experiment newly adopted, stimulated plant growth more than the gravel Culture method. And the treatment of low level nitrogen (A plot) in this water culture also saw a considerable degree of tuber formation, as in the case of gravel culture. 4) The foliar application of growth retardant B-nine suppressed the plant length only, with no other recognizable effect. II. Fffects of urea supplying level on the growth of IPOMOEA BATATAS. 1) The higher level of urea which was absorbed tby roots through nutrient solution suppressed top growth, such as plant length, number of leaves and fresh weight. And this can be attributed to the direct absorption of urea which was not ammonificated. 2) Although the higher level of nitrate nitrogen (B plot) made no tuber formation in previous experiment (Report-1), the higher level of urea nitrogen (A plot) made tuber formation possible in this experiment. The ratio of tuber to top was, however, less in higher level of urea than in lower level of urea, and the suppressing effect was larger on tuber than on top. 3) The foliar application of urea stimulated top growth while the higher level of urea absorbed by roots suppressed it, though the amounts of urea supplied in two experiments were same. Ratio of top to roots was larger in foliar application of urea (C plot) and less in root absorption of urea both of higher (B plot) and lower urea levels (A plot). III. Fffects of growth retardant etc. on the growth of IPOMOEA BATATAS in relation to urea application. 1) B-nine (N-dimethyl amino-succinamic acid) is recognized as a growth retardant, suppressed the plant length irrespective of urea levels. The treatment of gibberellin stimulated distinctly plant length, and the combined treatment of gibberellin and B-nine recovered completely the plant length which had been suppressed by B-nine. 2) B-nine increased fresh weight, especially, fresh weight of top both in lower and higher level of The degree of fresh weight increase varied according to concentrations of B-nine, of which the 0.15% of B-nine ($B_1$ plot) was the effective in higher level of urea. The effect of B-nine for increasing fresh weight was the largest in top next in tuber, and the least in fibrous roots. The ratio of fibrous roots to top was always decreased by B-nine application, which the ratio of tuber to top was contrary increased by B-nine in higher level of urea though decreased in lower level of urea. 3) Gibberellin treatment also increased fresh weight but the combined treatment ($B_3$+GA plot) of gibberellin and B-nine was even more effective than any of single treatments. Gibberellin and B-nine proved to be synergistic with fresh weight while reverse with plant length. 4) Considerable influences were abserved mainly in the length of plants and their fresh weight after B-nine treatment. So that B-nine may be reguraded as a metabolic controller rather than as an antimetabolite. 5) The surpressed growth of plants cause by higher level of urea was normalized by B-nine treatment. This fact suggested a further study on the applicability for practical use.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.2
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• pp.155-163
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• 1999

Nutrient balance during rice cultivation in the paddy of a local area under the environmental protection for drinking water supply was investigated. To compare nutrient balance in the paddy soil applied with different types of fertilization, 7 treatments were selected as followings : Recommended level of chemical fertilizers(R), Conventional fertilization(CF), Fresh cow manure(FCM), Cow manure compost(CMC), Straw compost+reduced chemical fertilizer(SCF), Fresh straw+recommended level of fertilizers(FSC), and no fertilization as control(C). Here, FCM, CMC and SCF were applied at the same level of total nitrogen as recommended in R. Rice yield was the highest in the recommendation(R) and fresh cow manure (FCM) treatments with $6,730kg\;ha^{-1}$(index 100), and followed by SCF (index 98), FSC (index 98), CMC(index 94), and CF(index 94). But statistically significant difference was not recognized among treatments except the control. Nitrogen infiltration loss was high in the simple chemical fertilizer treatments with $63kg\;ha^{-1}$ in CF and $58kg\;ha^{-1}$ in R during rice cultivation, respectively. Nitrogen infiltration loss was decreased below half level of chemical fertilizer treatments with cow manure treatments ($23kg\;ha^{-1}$ in FCM and $27kg\;ha^{-1}$ in CMC) and with reducing chemical fertilizer treatment by adding straw compost ($25kg\;ha^{-1}$). Phosphate was not leached during rice cultivation in paddy soil of a fluvial deposit type, in which oxidation horizon was developed broadly under around 15 cm depth of surface soil. Phosphate balance (A-B) was closed to 0 in all treatments except cow manure treatment (CMC), in which it was $+30kg\;ha^{-1}$ and show the possibility of over accumulation of phosphate by continuously replicated application of cow manure compost. Potassium balance was negative value in all but straw recycling treatment (FSC). It means that potassium was continuously supplied from soil minerals, uptaken by plants or eluted out of soil. In conclusion, by substituting inorganic fertilizer for organic fertilizer or reducing application rate of chemical fertilizer through mixing organic fertilizer, it would be possible to achieve the same rice yield as in the recommendation treatment and to decrease nutrient leaching below half level in rice paddy soil.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.1
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• pp.8-15
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• 2003

If contaminated river water is sprayed over a floodplain, the microbial processes can simultaneously remove organic matter and nitrogen during the infiltration through the sediment profile. The effect of rhizosphere on the removal of organic matter and nitrogen from contaminated river water was investigated using floodplain lysimeters. River water was sprayed at a rate of $68.0L\;m^{-2}\;d^{-1}$ on the top of the lysimeters with or without weed vegetation on the surface, Concentrations of $NO_3$, $NH_4$ and dissolved oxygen (DO), and chemical oxygen demand (COD) and Eh in water were measured as functions of depth for 4 weeks after the system reached a steady state water flow and biological reactions. A significant reductive-condition for denitrification developed in the 30-cm surface profile of lysimeters with weeds. At a depth of 30 cm, COD and $NO_3$-N concentration decreased to 5.2 and $0.9mg\;L^{-1}$ from the respective influent concentrations of 18.2 and $9.8mg\;L^{-1}$. The removal of $NO_3$ in lysimeters with weeds was significantly higher than in those without weeds. Vegetation on the top was assumed to remove $NO_3$ directly by absorption and to create more favorable conditions for denitrification by supply of organic matter and rapid $O_2$ consumption, In the lysimeters without weeds, further removal of $NO_3$ was limited by the lack of an electron donor, i.e. organic matter. These results suggest that the filtration through native floodplains, which include rhizospheres of vegetation on the surface, can be effective for the treatment of contaminated river water.

• Korean Journal of Environmental Agriculture
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• v.16 no.1
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• pp.19-24
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• 1997

This studies was carried out to investigate the soil contamination and water quality affected by agricultural activities in the Keum river Districts. Soil pH of the Keum river districts were $5.56{\sim}7.09$ in Keum river headwater and Namdae-cheon but that of Keumgang-lake were $5.07{\sim}7.21$ because of the cattle shed and industrial complex around. Total nitrogen contents of soils were found difference as period of fertilizer application. Total phosphorous content of soils no difference were found between the headwater and Keumgang-lake. Heavy metal contents of soils were natural background level. Water pH of the Keum river districts ranged from 6.59 to 7.80 and COD was maintain below 1.0 mg/L. Total nitrogen content affected by a livestock wastes and sewage water were the higher than that of others and total phosphorous content showed below 0.5 mg/L. Nitrate nitrogen and ortho-phosphate contents were very high according to the influence a livestock waste and sewage water in headwater region of the Keum river partly. Chlorine and sulfate contents were high according to the influence of sea water invasion. Heavy metal contents of waters were natural background level.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.2
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• pp.87-94
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• 1979

In order to study the water pollution in Suyeong Bay, Busan, some chemical constituents were determined at 25 stations in the neap tides on 9 Aug. 1977 and spring tides on 30 Aug. 1977. Range and mean values of the constituents in the spring tides are as follows: $pH\;6.54\~8.06,\;7.54;$ electrical conductivity $0.413\~0.481\times10^5\;\mu\mho/cm,\;0.467\times10^5\;\mu\mho/cm;\;transparency\;0.2\~5.5m,\;2.2m;$ turbidity $1\~60ppm$, 14ppm, chlorosity $15.20\~18.11g/\ell,\;17.67g/\ell;$ fluoride ion $0.94\~1.03ppm$, 0.99ppm; dissolved oxygen $0.17\~7.60ppm$, 4.77ppm; sulfide $0\~0.46ppm$, 0.07ppm; chemical oxygen demand $1.20\~40.74ppm$, 6.11ppm; ammonia-nitrogen $0.060\~0.520ppm$, 0.180ppm; nitrite-nitrogen $0.001\~0.026ppm$, 0.009ppm; nitrate-nitrogen $0\~0.037ppm$, 0.014ppm; phosphate-phosphorus $0.002\~0.261ppm$, 0.050ppm; n-Hexane soluble $0.5\~5.4ppm$, 2.1ppm ; iron $1.0\~104.11\;ppb$, 24.15ppb ; copper $0\~27.45ppb$, 4.19ppb; lead $0\~2.50ppb$, 0.92ppb; zinc $0\~5.15ppb$, 1.47ppb ; cadmium $0\~0.26ppb$, 0.04ppb; and mercury $0.05\~0.37ppb$, 0.11ppb respectively. The variations of the contents of the chemical constituents in the spring tides were larger than in the neap tides. The contents of COD, sulfide, nutrient salts and heavy metals were the highest in the estuary of Suyeong River, and decreased in order of off Kwangan-Ri region, outer Bay and off Haeun-Dae region. The water quality in Suyeong Bay was particularly shown that the concentrations of COO, iron, copper and mercury were higher than those of other coastal aseas and deficiency in dissolved oxygen was observed in some parte of Suyeong Bay. In consideration of the relationship between the chlorosity and the concentrations of nutrient salts, COD and total heavy metals, water pollution of this area is considered due to the inflow of Suyeong River which was extremely polluted by sewage and industrial wastewaters.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.1
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• pp.43-48
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• 1993

A laboratory study was cunducted to obtain fundamental informations on environmental-conservative treatment technique of soiled animalwaste. The release rate of inorganic nitrogen which mineralized from solid pigwaste and the effect of nitrification inhibitor(Dicyandiamide, DCD) on nitrate concentration of fresh or fermented pigwaste were weekly checked for ten weeks under incubation condition. Average pH of soild pigwaste was maintained over 8 unit during all incubation periods with no difference by nitrification inhibitor addition and the pHs of fresh- or fermented pigwaste without DCD were elevated by passing time 0.04, 0.058 pH unit/week (P<0.05) during incubation. While $NH_4-N$ concentration of fermented pigwaste until two week was nearly the same as it before incubation, $NH_4-N$ concentration of fresh pigwaste was remarkably increased upto 3,732 ppm for 1 week after incubation and the portion of increased $NH_4-N$ concentration, 2,473 ppm was 20.1% of indigenous organic nitrogen of fresh pigwaste. By the passing incubation time, $NH_4-N$ concentration began to lower linearly at not only fresh- but fermented pigwaste after 1 or 2 week, respectively and the $NH_4-N$ concentration loss rate at fresh pigwaste was 61.8 ppm/week with DCD addition and 72.3ppm/week with no DCD. There was positive relationship between $NO_3-N$ concentrations of fresh pigwaste by the addition of DCD or not and $NO_3-N$ concentraion was significantly lowered with DCD treatment($r=0.79^{**}$).