• Korean Journal of Soil Science and Fertilizer
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• v.6 no.4
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• pp.213-219
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• 1973

Effects of three slow-release nitrogen fertilizers (Sulfur-coated urea, (SCU) Jin Hae Chemical Co. Korea(JHC); Tennessee Valley Authority. U.S.A(TVA); METAP, Japan) on the yield and nitrogen uptake of IR667 (Suwon 213) were investigated comparing with urea split application under the field condition with early and usual saeson cultivation. 1. SCU(JHC) was not superior than urea split application in yield and nitrogen nutrition due to early release of nitrogen. 2. SCU(TVA) outyielded urea split by 10% showed always highest nitrogen content in straw and most balanced relative cumulative curve of nitrogen uptake or dry matter yield. 3. At ear formation stage SCU(TVA) showed specially high nitrogen content which was highly correlated with number of grain per $m^2$ of field. 4. Only SCU(TVA) showed one peak curve of nitrogen uptake rate at ear formation stage while others showed two peak pattern. 5. nitrogen fertilizer recovery of slow-release fertilizers was higher than urea split in early season cultivation and SCU (TVA) (46.0) was higher but SCU(JHC) (38.9) was similar in compare with urea split(37.1) in usual season cultivation. 6. Most promising slow-release nitrogen to match plant requirement seems to be one mixed of various slow-release fertilizers having different release pattern.

• Journal of Yeungnam Medical Science
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• v.7 no.2
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• pp.159-165
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• 1990

The prevalence of low serum urea nitrogen concentrations (< 6mg/dL) in our patient population was 3.8% (452 per 11,911 determinations), representing 372 individual cases. Of these, 323 of the patients charts were located, reviewed, and classified into disease groups. Malignant tumor was found in 25.1% of the 323 patients, the remaining patients without malignant tumor had various clinical conditions; pregnancy (19.5%), infectious diseases (12.1%), trauma (10.2%), cerebrovascular accident (62%), hepatopathy (5.3%), and miscellaneous conditions (21.6%). The prevalence in female and young aged patients under 5 years was considered due to the lower reference range in these groups than in that of female adult groups, and moreover pregnancy is another superimposing factor in the former group. In regards to the causes of this condition, our study corresponded well to the textbook cited etiology of the low serum nitrogen concentration, although malnutrition and hepatopathy were inverted in their incidental order. We postulated, through the present study, that the low serum urea nitrogen concentration is not pathognomonic findings to suggest specific disease or conditions, but rather to reflect patient's general conditions such as hydration, nutrition, or administration of certain drugs.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.1
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• pp.44-49
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• 2015

Urea has been the most useful N-source, due to lower cost per unit of N. But nitrogen use efficiency of urea may be reduced because of losses from agricultural system by volatilization of ammonia to atmosphere. This study was conducted to evaluate the nitrogen efficiency and growth of hot pepper (Capsicum annuum L.) by mixed treatment with nitrogen and zeolite. They were treated with N $161kg\;ha^{-1}$, N $230kg\;ha^{-1}$, nitrogenzeolite mixture (NZM) $161kg\;ha^{-1}$, NZM $230kg\;ha^{-1}$ and N $0kg\;ha^{-1}$, respectively. In the soil chemical properties after experiment, soil pH decreased but available $P_2O_5$, EC and total nitrogen increased in nitrogen-zeolite mixture treatment. $NO_3-N$ content in the soil showed the highest level in NZM $230kg\;ha^{-1}$. NZM $161kg\;ha^{-1}$ treatment increased growth and yield of hot pepper compared to urea alone. Nitrogen utilization efficiency of hot pepper plant was 47.15% at the treatment of NZM $161kg\;ha^{-1}$, while 36.74% at N $230kg\;ha^{-1}$. These results showed that application of mixture of nitrogen and zeolite had positive influence to improve the efficiency of nitrogen utilization and increase of red pepper yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.20
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• pp.122-133
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• 1975

In recent years, farmers have substituted urea for ammonium sulfate as nitrogen fertilizer in their crop production. Since crops can not take urea itself directly as it is, we attempted to determine the amount of decomposition of urea in soil. It was observed that 25 percent of urea which had initially mixed with soil was decomposed in 10 days at 15$^{\circ}C$ and 80 percent in 2 days at $25^{\circ}C$. Therefore, it was considered that large amount of urea could be lost in cool season and cool areas. In the other experiment, ammonium sulfate, as a source of sulfur, was so mixed with urea that the ratio of sulfur to nitrogen would be 15 percent. Small amount of dolomite was also added to this mixture and the resulting fertilizer was applied on the rice plants. Eight percent of yield increase was obtained together with the increased protein content in brown rice.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.4
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• pp.357-363
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• 1997

The effect of replacement of cotton seed meal (CSM), with various levels and sources of non-protein nitrogenous (NPN), substances on in vitro ruminal fermentation were studied. Cotton seed meal, in control ration provided nitrogen equivalent to 12.5 percent crude protein while in experimental ration was replaced at 30, 50 & 70 percent levels with urea, diammonium phosphate (DAP) and biuret, respectively. The results of incubation upto 48 hours indicated an improvement in digestibility by replacement of CSM with urea and biuret upto 50 percent protein equivalent, but not with DAP. Bacterial count from cultures containing 50% nitrogen from biuret was significantly higher than DAP, urea and CSM. Various sources of nitrogen produced $NH_3-N$ in increasing order of CSM, biuret, DAP and urea. Increasing levels of NPN resulted in progressive increase in the levels of $NH_3-N$. The levels of various NPN sources had no effect on pH. However, the pH values determined for urea and CSM were higher than biuret and DAP.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.2
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• pp.114-120
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• 2000

The aim of this study was to investigate the effects of slow-released nitrogen fertilizer(SRNF) on the growth and yield of rice. SRNF produced from wasted paper was applied to a clay loam paddy field comparing to urea fertilized field and only P-and K-fertilized field. Some agronomic components like as growth development and yield component were observed and physico-chemical properties of the soils were analyzed. Plant height and tiller numbers per hill showed higher in rice plant treated with SRNF than in one treated with urea at the early grow stage whereas they appeared to be all much the same at the end of growth stage. While the chlorophyll content in SRNF-treated rice shoot was higher than in urea-treated one, the photosynthetic activity in urea-treated rice shoot was slightly higher than in SRNF-treated rice. In harvested grain, the nitrogen content was higher than in SRNF treated rice than in urea treated rice, but in straws the content was less. At the harvesting stage, nitrogen uptake in grains was about 4% higher in SRNF-treated rice than in urea treated rice whereas in straws rather 20% lower. The N efficiency in SRNF treated rice was lower than in urea treated rice. In the soils treated with SRNF, pH, organic matter and phosphorus were higher than in the soils treated with urea. Total N content in SRNF treated soil was lower after experiment than in urea treated soil.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.4
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• pp.619-622
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• 1993

Rumen bacterial amino acids in sheep on urea diet were monitored to assess a possible change in amino acid synthesis as a long term response to high rumen ammonia environment. A sheep was fed a semipurified diet with soybean meal, followed by a diet with urea as a main nitrogen source. Mixed rumen bacteria were harvested from ruminal fluid taken 3 h after feeding (twice in soybean meal feeding and 6 times in urea feeding) and fractionated as cell wall, proteins and protein-free cell supernatant of monitor amino acids in each fraction. Ruminal ammonia concentration at the sampling ranged from 5.7 to 39.5 mgN/dl. Cell wall and protein fractions of mixed rumen bacteria were stable in their amino acid composition regardless of nitrogen sources of diet and the feeding duration. However, protein-free cell supernatant fraction showed a higher alanine proportion with urea feeding (18.6 and 28.2 molar % of alanine for samples from sheep fed soybean meal and urea, respectively) and its duration (20.6 and 32.9 molar % for samples from sheep on urea diet for 1 and 65 days, respectively). Total free amino acid level of bacteria was depressed in the initial period of urea feeding but restored on 65th day of the feeding. These results suggest that an alanine synthesizing system may develop in rumen bacteria as urea feeding becomes longer.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.8
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• pp.1159-1163
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• 2008

Data of 42 balance measurements from dry and lactating Holstein cows and blood and urine samples from 24 Japanese Black cows were collected to evaluate the potential for predicting urinary nitrogen (N) excretion from plasma urea nitrogen (PUN). Similar positive correlations were obtained between N intake and apparent N absorption in dry and lactating cows. The regression equations of N intake on urinary N excretion varied in dry and lactating cows, and the difference of urinary N excretion between dry and lactating cows was due to the N secretion into milk. Highly positive correlations were observed between urinary N contents and urinary urea N in Japanese Black cows, and urinary urea N increased with increasing PUN. There were positive correlations between N intake and PUN in dry and lactating cows, but PUN and urinary N excretion in lactating cows were higher than in dry cows. There were positive correlations between PUN and urinary N excretion per BW in dry and lactating cows. Although urinary N excretion could be calculated as (N clearance rate of kidneys)PUNBW, high N clearance rate of kidneys, such as 2.08 L/d/kg BW, may be suitable to calculate urinary N excretion in lactating cows, compared with 1.33 L/d/kg BW in dry cows.

• Journal of Nutrition and Health
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• v.21 no.1
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• pp.47-60
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• 1988

This study was performed to investigate the effect of dietary levels on protein metabolism in eight healthy Korean adult females. The 20-day metabolic study consisted of 2 day adaptation period and three 6-day experimental. Three experimental diets were low protein (LP : protein 44g), high protein(HP : protein 85g) and high animal protein (HAP : protein-84g). The apparent absorption and balance on nitrogen were significantly higher in high protein than in low protein diet. Nitrogen, absorption rate was about 75% for low protein and about 85% for high protein intake. The mean values of nitrogen balance were -1.28% for low protein and 0.78% for high protein diet. All the subjects were in negative nitrogen balance at the low protein intake while they were in positive nitrogen balance at the high protein intake. The mean daily urinary nitrogen excretion increased with increased level of protein intake. Urea nitrogen was the largest part of the urinary nitrogen. The ratio of urea nitrogen to total urinary nitrogen increased significantly for 79 to 85% as protein intake was doubled.

• Korean Journal of Poultry Science
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• v.12 no.1
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• pp.17-24
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• 1985

In order to investigate an effect of non-protein nitrogen on the biological utilization of protein, hatched single comb White Leghorn male chicks were fed for the first 8 days with a commercial chicks mash, next 6 days with protein-free diet and subsequent 6 days with protein-free diets and protein diets containing 10.59% of crude protein supplemented with 0, 0.5, 1.0 and 1.5%, respectively. During experimental feeding period, chicks fed protein-free diets had intaked gradually lower feed and had shown a similar body weight loss though urea contents were increased. When birds fed protein diets, body weight gain and feed intake were not different among birds fed the graded levels of urea although feed conversions were shown a highering tendency along with increasing urea contents. According as supplemented urea were increased, protein efficiency ratio f (PER) and net protein ratio (NPR) were increased in chicks fed protein-free diets, which were shown a lowering trend in chicks fed protein diets. Effect of supplemented urea on the urinary excretion of uric acid were not found in birds fed protein-free diets, while which were increased in birds fed protein diets with the increase of urea contents. Urea addition did not affect the excretion of total creatine in birds fed protein-free or protein diets. Excretion of ammonia was jogjered in order to increasing level of urea in birds fed protein-free diets, but which were not found any particular effect in birds fed protein diets. Also urea excretion were gradually increased with the increasing contents of urea in protein-free and protein diets. Nitrogen balance of birds fed protein-free diets were minus values, which were increased with increasing urea contents in diets. When birds fed protein diets, nitrogen balance and urinary nitrogen excretion was highered and fecal nitrogen excretion were not altered as urea levels of diets increased. Digestibility of urea nitrogen supplemented in protein-free diets were lowered along with increasing contents of urea, but biological value(BV) and net protein utilization(NPU) was found a highering tendency in birds fed protein-free diet containing 1.5% of urea. When birds fed with protein diets, digestibility, BV and NPU of protein were found a highering trend in birds fed protein diets added with 0.5% of urea.