• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.106-106
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• 2022

An appropriate amount of nitrogen fertilizer input during rice cultivation is essential for rice growth, quality control, and reduction of greenhouse gases in paddy fields. Therefore, it is necessary to develop a technology that can check whether an appropriate amount of fertilizer is applied in paddy fields. In this study, we tried to derive a method for diagnosing nitrogen fertilization level using spectroscopic diagnosis, physiological analysis, and molecular indicator genes. Nitrogen fertilization treatment was performed in a greenhouse by dividing into five treatment conditions: no fertilization (N0), low fertilization (N0.5), standard fertilization (N1.0), excessive fertilization (N1.5), and double fertilization (N2.0), respectively. Growth characteristics analysis was investigated by nitrogen fertilization conditions and growth stages, and the height of the canopy was analyzed using a laser scanner. Physiological and spectroscopic analyses were performed by analyzing chlorophyll and sugar contents and measuring SPAD and leaf spectrometer on rice leaves. In addition, real-time PCR experiment was performed to check the relative expression levels of several known nitrogen metabolism related genes. These results suggest that spectroscopic techniques can be helpful in diagnosing the level of nitrogen fertilization in rice paddy fields.

• Korean Journal of Veterinary Research
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• v.18 no.2
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• pp.77-86
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• 1978

The present study was carried out to evaluate the effect of Panax ginseng on the metabolism of nonprotein nitrogen compounds in rabbit blood. After rabbits were administered with ginseng powder orally for 30 days or with ginseng extract intraperitoneally for 10 days, the blood was collected from portal and ear vein to measure ammonia, urea, creatinine and nonprotein nitrogen. The blood ammonia level in ear vein of control rabbits was $87.0{\pm}5.1{\mu}g/100ml$ and was not significantly different from that of rabbits which were administered with ginseng powder orally or with ginseng extract intraperitoneally. But oral administration of ginseng powder produced a great decrease in ammonia level of portal vein from 1,392 to $704{\mu}g$ per 100ml, suggesting that intestinal ammonia production is suppressed by ginseng powder due to its antimicrobial activity. While there was no significant difference between the control and the rabbits which were administered with ginseng extract intraperitoneally. Ginseng administration had no effect on the creatinine level in blood from ear and portal vein, except the intraperitoneal injection of ginseng extract. It slightly lowered the creatinine level only in ear vein blood. The values of urea and nonprotein nitrogen were net affected by the administration of ginseng.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.3
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• pp.280-285
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• 2004

This paper is concerned with the modeling and identification of sequencing batch reactor (SBR) via genetic algorithm based polynomial neural network (GA-based PNN). The model describes a biological SBR used in the wastewater treatment process fur nitrogen removal. A conventional polynomial neural network (PNN) is applied to construct a predictive model of SBR process fur nitrogen removal before. But the performances of PNN depend strongly on the number of input variables available to the model, the number of input variables and type (order) of the polynomials to each node. They must be fixed by the designer in advance before the architecture is constructed. So the trial and error method must go with heavy computation burden and low efficiency. To alleviate these problems, we propose GA-based PNN. The order of the polynomial, the number of input variables, and the optimum input variables are encoded as a chromosome and fitness of each chromosome is computed. Simulation results have shown that the complex SBR process can be modeled reasonably well by the present scheme with a much simpler structure compared with the conventional PNN model.

• Journal of Bio-Environment Control
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• v.7 no.3
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• pp.253-258
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• 1998

Lettuce plants(Lactuca sativa var. capitata L.) were subjected to nitrogen starvation for 18, 14, 11, 7, and 0 days before harvest. The nitrate content of lettuce was decreased greatly by nitrogen starvation and also its fresh weight. The nitrate content of the middle part of leaves was lowest at the treatment of 18 days before harvest. In the inner part it was lowest at the treatment of 11 and 14 days before harvest. The longer the period of nitrogen starvation was, the more were decreased the absorption rates of cations at harvest. During the experiment, the pH was decreased except the treatment of 7 days before harvest. The EC was continuously increased regardless of treatments.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.5
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• pp.698-701
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• 2000

To prevent surface and underground water pollution, wastewater treatment is essential. Four bench-scale activated sludge units (10 L operational volumes) were operated at 5, 10 and $20^{\circ}C$ for evaluation of treatment efficiencies with typical wastewater from swine housing. The units were set for a 24-hour cycle. As compared to the conventional process, high removal efficiencies for organic substances, nitrogen and phosphorus in swine wastewater were obtained simultaneously with an intermittent aeration process (lAP). The NOx-N produced during an aeration period was immediately reduced to nitrogen gas (e.g. $N_2$ or $N_2O$) in the subsequent non-aeration periods, and nitrification in aeration periods occurred smoothly. Under these conditions, phosphorus removal occurred with the release of phosphorus during the non-aeration periods followed by the excess uptake of phosphorus in the activated sludge during aeration periods. It was confirmed that the lAP had a better ability to remove pollutants under both low temperatures and high nitrogen loading conditions than the ordinary method did. In addition to that, the total emission of $N_2O$ from lAP was reduced to approximately 1/50 of the conventional process for the same loading. By adopting an adequate aeration programme for individual swine wastewater treatment, this system will provide a promising means for nitrogen and phosphorus control without pH control or addition of methanol.

• Journal of the Korean Ceramic Society
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• v.51 no.3
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• pp.201-207
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• 2014

High-purity aluminum nitride nanopowders were synthesized using an RF induction thermal plasma instrument. Ammonia and nitrogen gases were used as sheath gas to control the reactor atmosphere. Synthesized AlN nanopowders were characterized by XRD, SEM, TEM, EDS, BET, FTIR, and N-O analyses. It was possible to synthesize high-purity AlN nanoparticles through control of the ammonia gas flow rate. However, additional process parameters such as plasma power and reactor pressure had to be controlled for the production of high-purity AlN nanopowders using nitrogen gas.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.3
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• pp.363-368
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• 2018

Objective: The objective of the study was to determine the effect of fermented spent coffee ground (FSCG) on nutrient digestibility and nitrogen utilization in sheep. Methods: Fermentation of spent coffee ground (SCG) was conducted using Lactobacillus plantrum. Fermentation was performed at moisture content of 70% and temperature of $39^{\circ}C$ with anaerobic air tension for 48 h. Four adult rams (initial body weight = $56.8{\pm}0.4kg$) were housed in a respiration-metabolism chamber and the treatments were: i) control (Basal diet; 0% SCG or FSCG), ii) 10% level of SCG, iii) 10% level of FSCG, and iv) 20% level of FSCG in $4{\times}4$ Latin square design. Each dietary experiment period lasted for 18-d with a 14-d of adaptation period and a 4-d of sample collection period. Results: In SCG fermentation experimental result, acid detergent insoluble nitrogen (ADIN) concentration of FSCG (64.5% of total N) was lower than that of non-fermented SCG (78.8% of total N). Digestibility of dry matter and organic matter was similar among treatment groups. Although crude protein (CP) digestibility of the control was greater than FSCG groups (p<0.05), the 10% FSCG group showed greater CP digestibility and nitrogen retention than non-fermented 10% SCG group (p<0.05). Body weight gain and average daily gain were linearly decreased with increasing FSCG feeding level (p<0.05). When the feeding level of FSCG was increased, water intake was linearly increased (p<0.05). With an increasing FSCG level, dry matter intake did not differ among groups, although the gain to feed ratio tended to decrease with increasing level of FSCG (p<0.10). Conclusion: Microbial fermentation of SCG can improve protein digestibility, thereby increasing CP digestibility and nitrogen utilization in sheep. Fermentation using microorganisms in feed ingredients with low digestibility could have a positive effect on improving the quality of raw feed.

• The Korean Journal of Ecology
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• v.19 no.4
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• pp.341-351
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• 1996

In order to elucidate the differences in early successional development among similary aged old-fields having different soil nitrogen (N), caused by the land use history before at abandonment, the response of plant community along an experimental nitrogen gradient (control plot (No), plot NI with 5.8g $N/m^2$, plot N2 with 11.7g $N/m^2$ and plot N3 with 23.3g $N/m^2$) was investigated in a five-year-old abandoned field. Although the N content in soil among treatments was similar at the end of the growing season, N concentrations in plant tissue increased with the amount of N supplied. These results suggest that almost all the N contained in N-enriched soil might be absorbed by plants during the growing season after N supply. Vegetation tended to grow vigorously by nitrogen supply, and the standing biomass increased significantly in plots NI and N2 . Species richness of plants, especially of annuals and perennials, was more reduced than the control plot, and the species diversity was also reduced by N supply. The importance value (IV) of species by N supply differed in each species along the position on the successional sere: Artemisia princeps var. orientalis as the dominant species in this old-field decreased slightly; annuals as the earlier successional species decreased clearly along nitrogen gardients; Erigeron annuals as the earlier successional species and as a strong competitor with Artemisia princeps var. orientalis had the highest IV by small N supply; Miscanthus sinensis and Rubus crataegifolius as the later successional species increased by large N supply. These results suggest that old-fields with high soil N might show the structural and functional characteristics of the earlier successional stages, but community composition in those old-fields might be changed more quickly from the sarlier successional species than the later successional species.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.4
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• pp.455-461
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• 1988

The pattern of nitrogen fixation by water culture of Sesbania, known as an effective legume plant for nitrogen fixation, in the growth cabinet by Leonard-Jar methods and nitrogen fixation pattern to sesbania are as follows: 1. Dry weight per pot after inoculation of rhizobia to sesbania was by the order for root + stem > root > control and nitrogen contents of plant parts also showed the same tendency as dry weight except leaf. 2. $^{15}N$ value based on natural abundance was by the order of root + stem > root > control, $^{15}N$ value of root nodule and stem nodule among total nitrogen content exhibited positive value but it showed negative value from root, stem and leaf.

• Journal of Ecology and Environment
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• v.30 no.2
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• pp.161-170
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• 2007

The ultimate target of restoring waste landfills is revegetation. The most effective method for increasing species richness and biomass in nutrient limited waste landfills is the use of fertilizers. The aim of the present study was to investigate the effects of nitrogen fertilizer, and the addition of carbon through sawdust, sucrose and litter, on vegetation dynamics at a representative municipal waste landfill in South Korea: Kyongseodong. A total of 288 permanent plots $(0.25m^2)$ were established and treated with nitrogen fertilizer (5, 10 and $20Ng/m^2$), sawdust $(289g/m^2)$ sucrose $(222g/m^2)$ and litter $(222g/m^2)$. The aboveground biomass was significantly enhanced by nitrogen fertilizer at 5 and $10Ng/m^2$, compared with the control plots. The total cover of all plant species increased significantly on plots treated with 5 and $20Ng/m^2$, as well as on those treated with sawdust and sucrose, compared with the control plots. The higher species richness after nitrogen fertilization of 10 to $20Ng/m^2$, and the sawdust and sucrose treatment demonstrated that this was an appropriate restoration option for nutrient deficient waste landfills. This study demonstrated positive nutrient impacts on plant biomass and species richness, despite the fact that municipal waste landfills are ecosystems that are highly disturbed by anthropogenic and internal factors (landfill gas and leachate). Adequate N and C combined treatments will accelerate species succession (higher species richness and perennial increase) for restoration of waste landfills.