• Applied Biological Chemistry
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• v.19 no.3
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• pp.172-183
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• 1976

RNA, DNA and other phosphorus fractions were determined in the leaf and root of soybean plants different in phosphorus sensitivity grown in $NH_4-N,\;NO_3-N$ and urea medium. The phosphorus sensitive cultivars contained higher ASIP (acid soluble inorganic phosphorus) than the tolerant cultivars with all nitrogen sources. ASIP was highest in the urea treated plants and lowest in the nitrate treated plants. Total phosphorus content was mostly affected with increase in ASIP. When ASIP increased, acid solsuble organic phosphorus(ASOP), phospholipids (L-P), RNA-P, residual phosphorus (R-P) tended to increase, while DNA-P showed little change. The percent RNA-P or DNA-P of total phosphorus in the nitrate treated plant was twice that in the ammonium treated plant, which were also higher in tolerant cultivars regardless of nitrogen sources. The percent ASOP in total acid soluble phosphorus $(ASOP/ASP{\times}100)$ decreased as phosphorus sensitivity decreased. Indications are that phosphorus sensitivity depends on the relative sizes of phosphorus metabolic pools. Total dry matter yield was negatively correlated with total phosphorus (r=0.84 significant at 0.01P), ASIP (0.84 significant at 0.01P) and residual phosphorus (0.69 significant at 0.05P). ASOP showed positive correlation with L-P, RNA-P and DNA-P but negative with R-P. RNA-P was significanly correlated only with L-P (0.63 at P=0.01). There was significant interaction (0.01) among nitrogen sources, cultivars and phosphorus metabolic pools. Phosphorus sensitivity and ammonium toxicity appear to be same in view of energy metabolism, that is, the former inhibits the conversion of ATP to ADP (energy releasing) through phosphate potential while the latter inhibits ATP formation (energy storing).

• Journal of Ecology and Environment
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• v.29 no.3
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• pp.305-321
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• 2006

Atmospheric Acid Deposition: Nitrogen Saturation of Forests: Volume weighted annual average wet deposition of nitroge at 33 sites in Korea during 1999-2004 ranged 7.28 to $21.05kgN{\cdot}ha^{-1}{\cdot}yr^{-1}$ with average $12.78kgN{\cdot}ha^{-1}{\cdot}yr^{-1}$, which values are similar level with nitrogen deposition of Europe and North America. The temperate forests that suffered long-term high atmospheric nitrogen deposition are gradually saturated with nitrogen. Such nitrogen saturated forest watersheds usually leach nitrate ion ($NO_3^-$) in stream water and soil solution. It may be likely that Korean forest ecosystems are saturated by much nitrogen deposition. In leaves with nitrogen saturation ratios of N/P, N/K and N/Mg are so enhanced that mineral nutrient system is disturbed, suffered easily frost damage and blight disease, reduced fine-root vitality and mycorrhizal activity. Consequently nitrogen saturated forests decrease primary productivity and finally become forest decline. Futhermore understory species are replaced the nitrophobous species by the nitrophilous one. In soil with nitrogen saturation uptake of methane ($CH_4$) is reduced and emission of nitrogen monoxide (NO) and nitrous oxide ($N_{2}O$) are increased, which gases are greenhouse gas accelerating global warming.

• Microbiology and Biotechnology Letters
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• v.4 no.4
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• pp.145-151
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• 1976

Cultural characteristics of a strain of Streptomyces sp. K-14 (KFCC 35051) producing glucose isomerase were demonstrated. The glucose isomerase was produced when the strain was grown in the medium containing pure xylan or xylan.containing materials such as wheat bran or com cob. The optimum condition was attained in a culture medium composed of 3 % wheat bran or com cob, 2 % com steep liquor, 0.1% $MgSO_4$$7H_2O$ and 0.012 % $CoSO_4$$7H_2O$ for the production of the glucose isomera,e. The production of the enzyme reached to a maximum level when the strain was cultured for 40 hrs $30^{\circ}C$ and pH 7.0.

• The Korean Journal of Ecology
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• v.17 no.3
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• pp.311-318
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• 1994

We examined spatial and temporal patterns of root decomposition for three and half years, from October 1986 to April 1990, in semi-arid Chihuahuan Desert. Decomposition of roots occurred in a two-phased pattern: an early period of rapid mass loss followed by a period of slower loss. The rate of root decomposition had a high negative correlation with the initial lignin concentration in roots (r=-0.84, p<0.05). Annual mass loss rate of Baileya multiradiata, a herbaceous annual, was the highest with the value of 0.60, while that of Panicum obtusum. a perennial grass which was restricted to playa, was the lowest with 0.13. The mass loss rate of roots in the playa was the lowest among the vegetation zones along the transect. After 42 months elapsed, fluffgrass roots in playa lost 40% of the initial mass, while in other sites it lost on average 55% of the initial mass. In all roots except for desert marigold, there was an initial release of nitrogen early in decomposition followed by net nitrogen immobilization. Nitrogen concentration of the desert marigold roots showed linear increase from the beginning. Lignin concentration of perennial grass roots were higher than those of herbaceous annual and woody perennial root.

• Journal of Animal Science and Technology
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• v.44 no.1
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• pp.55-60
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• 2002

Two experiments were conducted to investigate the effect of dietary supplementation of plant phytase (Phytazyme$^{(R)}$) in corn-soybean meal based diets on utilization of phytase-bound phosphorus in laying hens and evaluate nitrogen(N) digestibility and phosphorus(P) availability in breeders. In the experiment one, three levels of the Phytazyme$^{(R)}$(0.05, 0.1, and 0.2% of diet) were added to diets containing a half of control TCP level(0.96%) for 4 wks. Feed consumption, egg production rate, egg weight and eggshell quality were recorded weekly. At the end of experiment, 8 birds per treatment were sacrificed, liver weight were weighed and right tibiae were removed for determination of P content. The second experiment was conducted to evaluate the P availability and nitrogen digestibility in breeders fed same diets for 2 wks. Feed and excreta were collected to determine the P and N contents for the last three days of experiment two. Addition of Phytazyme$^{(R)}$ resulted in no effects on feed intake, egg product rate, egg weight and egg shell quality. P excretion decreased and its availability enhanced as phytase supplementation increased in diets. Dietary supplementation of Phytazyme$^{(R)}$ above 0.1% level in corn-soybean meal based diets did not have an adverse effect on production and decreased level of phosphorus in excreta.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.223-226
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• 2012

Liquid livestock manure (LLM) has been used as a nitrogen fertilizer source for horticulture plants. LLM contains organic nitrogen (N), ammonium, nitrate, and nitrite. The amount of nitrate and nitrite in LLM are usually small compared to the amount of ammonium in it and so they can be negligible if total nitrogen (N) concentration in LLM is higher than $1,000mg\;L^{-1}$. However, if total N concentration in LLM is less than $1,000mg\;L^{-1}$, the amount of nitrate and nitrite may affect total N concentration in LLM. Currently, Kjeldahl digestion method is mainly used for ammonium-N in LLM. Therefore, it is ineffective to analyze nitrate-N and nitrite-N. The objective of this study was to evaluate whether the total N concentrations are affected by the amount of nitrate-N and nitrite-N with diverse LLMs by Kjeldahl method (with and without Devarda's alloy after Conc. sulfuric acid digestion). Five liquid livestock manure samples were collected at swine farms in Ansung and Icheon. All LLM samples were stored at $25^{\circ}C$, subsampled at every $15^{th}$ day for 90 days, and analyzed for total N, ammonium-N, and nitrate-N. At the $90^{th}$ day, LLM samples were analyzed with and without Devarda's alloy after Conc. sulfuric acid digestion. Potassium nitrate, ammonium nitrate, and ammonium chloride were used to determine the N recovery percentages. Total N concentration ranged from 560 to $4,230mg\;L^{-1}$. Nitrate-Ns were found in all LLM samples, ranged from 21 to $164mg\;L^{-1}$. N recovery percentages with potassium nitrate were 0 % without Devarda's alloy and 100% with Devarda's alloy because adding Devarda's alloy facilitated nitrate-N into ammonium-N conversion. Total Ns were significantly different between two methods, with and without Devarda's alloy. Total N concentrations were $210mg\;L^{-1}$ at LLM 4 and $370mg\;L^{-1}$ at LLM 5 without Devarda's alloy and $290mg\;L^{-1}$ at LLM 4 and $490mg\;L^{-1}$ at LLM 5 with Devarda's alloy. These results suggest that if total N of LLM is less $1,000mg\;L^{-1}$, additional procedure such as adding Devarda's alloy can be used to estimate the total N and inorganic N better.

• Journal of Plant Biology
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• v.22 no.1_2
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• pp.5-14
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• 1979

In several leguminous plants such as acasia, arrowroot and bushclover, growth rate and contents of nitrogen, phosphorus and potassium in the tissues and the variation in the culture media were determined. In water cultrue which was free of added nutrients, nitrogen was found to be largely in the form of nitrate(NO3-N). This NO3-N is believed to be the result of nitrification from NH4-N which was apparently released form the plants. From the studies of organ culture with root segments, the amount of nitrogen released and absorbed was found to be proportional to the amount added to the mediuim. Especially, in the N-plot, the amount of nitrogen absorbed by the tissue reached more than 90% of the amount supplied to the medium already in early stage. On the contrary, in the amount free plot, the amount of nitrogen released from the tissue was lower than the minimum level in the N-plot. The amount of total N and P in the cultured tissue was found to be influenced by the amount of nitrogen addedin the medium. However, the amount of K in the tissue was not related to the nitrogen level in the medium, but rather it was influenced by the amount of added potassium. These findings present little difference in the metabolic pattern among the three species plants studied, and suggest that the woody leguminous plants have some common features in tehir metabolic pattern.

• Korean Journal of Organic Agriculture
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• v.21 no.4
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• pp.647-657
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• 2013

This experiment was done to evaluate the effects of green manure cropping in green house soil on the changes of soil nutrients and soil microorganisms. The biomass of green manure crop was the highest in ryegrass and nitrogen absorption was the highest in hairy vetch. After cropping, soil phosphate content was the lowest in ryegrass, however, biomass C was the highest of all the green manures. Nitrogen uptake of plant and nitrogen content of the soil after the experiment showed a negative correlation. Total N content of soil was increased in hairy vetch plot, but decreasing tendency showed in the ryegrass and common crabgrass plots. In this results are summarized that green manure cropping greatly reduced salt accumulation in green house.

• The Korean Journal of Ecology
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• v.27 no.3
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• pp.155-159
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• 2004

In order to gain a better understanding of how forests participate in the cycling of carbon, effects of nitrogen addition on soil respiration were investigated on the oak forest in Kongju, Korea. Study site was divided into control, treatment f and treatment 2 plots, with 5 replication in each plot. In each replicate of treatment 1 and treatment 2 were fertilized with ammonium nitrate (NH$_4$NO$_3$), 30 g/$m^2$ and 60 g/$m^2$, respectively. Soil respiration, soil temperature, ammonium-N and nitrate-N were measured during the experimental period. Ammonium-N and nitrate-N in Ta were higher than those in control and T$_1$. Ammonium-N and nitrate-N in top-soil and sub-soil decreased sharply in August after bi9 rainfall in July in T$_1$ and T$_2$, however, those in control plot increased. Soil respiration in T$_2$ Plot showed consistently higher than those in control and T$_1$ until the end of July. However, soil respiration was similar among the control, T$_1$ and T$_2$ in mid-August and September The amount of Co$_2$ released from soil respiration in control, T$_1$ and T$_2$ in mid-August was 8.0$\pm$0.4, 9.3$\pm$0.6 and 10.2$\pm$0.5 $\mu$mol$^{-1}$ ㆍm$^{-2}$ ㆍs$^{-1}$ , respectively. However, those in control, T$_1$ and T$_2$in mid-August was 13.0$\pm$0.4, 13.5$\pm$0.5, 13.3$\pm$0.6 $\mu$mol$^{-1}$ ㆍm$^{-2}$ ㆍ$^{-1}$ , respectively. The results suggest that nitrogen addition in this oak forest has a positive effect on soil respiration.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.1
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• pp.43-48
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• 1998

No-tillage silage corn with legume hairy vetch(Vicia villosa Roth, HV) has renewed interest in supply of mineral N, soil erosion control at sloping land and weed control by cover of HV killed. This study was conducted to monitor concentration of soil mineral N ($NO_3^-$ -N + $NH_4^+$-N) and to find out variation of growth, yield and N uptake of silage corn according to quantity of HV cover; HV-removed, 1X-HV, 2X-HV at field of Crop Experiment Station in 1996. HV groM in early spring decreased the mineral N of soil depth 7.5 -22cm before corn seeding. But, killed HV cover increased the concentration of soil mineral N at surface soil (0-7.5cm) up to 45.4mglkg at early growth stage of corn. Dry matter(Dh4) of corn at harvest was lower in W-removed than in Okg FNlha. But DM and N uptake of corn at harvest were increased by quantity of HV-cover increasing liom HV-removed to 2X-HV. Hairy vetch could substitute N fertilizer for silage corn by N mineralized h m HV killed, but reduced early growth and N uptake of corn before silk by reducing soil mineral N of plow layer.