• Journal of Plant Biology
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• v.4 no.2
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• pp.51-61
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• 1961

In order to detect the way of absorption and metaboism of the urea it is sprayed on the surface of the leaves of sunflower. The sunflowers used in this study are grown in different conditions such that the one in nittogen aboundant and the other in nitrogen deficient soil, respectively. The urea-N, ammonia-N, amide-N, and 80% alcohol soluble-N in the leaves were quantitatively determined. All of the nitrogenous components measured are generally tended to increased with rising the concentration of urea except only amide-N at 24 hours after sprayed, and these were highly significances. It seemed that hydrolizing of urea into ammonia and carbon dixide and the assimilation of ammonia into other organic nitrogenous constituents were rapid in the young leaves than in the mature. It is interest that the amide content, in the young leaves and nitrogen defieient one were enhanced with the increasing concentration of urea, although in the mature leaves it did not show any change in the urea treatment. It is presumed that the assimilation rate of ammonia and the urease activity were lower in the matture leaves than in the young and nitrogen deficient leaves. No significance at 5% level showed all of the nitrogenous components except total nitrogen between nitrogen abundant and deficent leaves. Urea content was a high peak at first 12 hours, ammonia at 48 hours, and amide and alcohol soluble nitrogen at 96 hours, whence decrease4d the content of these constituents gradually. The total nitrogen content is not incrased obviously by only one time of urea spray in this study. When the concentration of urea was relatively high there appeared the wilting spots on t도 edge of leaves. As a whole, it seemed that sprayed urea was rapidly absorbed and taken part in nitrogen metabolism within relatively short period.

• Journal of Applied Biological Chemistry
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• v.65 no.1
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• pp.1-6
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• 2022

Urea is one of the most common nitrogen fertilizer, but nitrogen use efficiency by crop is low because of rapid hydrolysis of urea and loss of nitrogen in environments. Therefore, it is important to control the nitrogen release from nitrogen fertilizers. In this study, pyroligneous acid (PA) was used as a mean to inhibit urease in soil and prevent excessive nitrogen release from urea. Active ingredient in PA (AI) inhibited ammonification of urea in soil by reducing extracted ammonium nitrogen at 79.7% compared to the soil without PA. In order to evaluate the effect of PA on fertilization efficiency of urea, Chinese cabbage (Brassica campestris var. Pekinensis) was cultivated in soil treated with urea and PA both in pot and field. For PA treatment, half amount of urea was used compared to the amount of urea conventionally applied to Chinese cabbage. The PA treatment with half amount of urea resulted in similar Chinese cabbage biomass to the conventional urea application. Nitrogen concentration in Chinese cabbage was less in PA treatment indicating that Chinse cabbage effectively used nitrogen. Consequently, fertilization of urea with PA will reduce amount of fertilizer and frequency of application.

• Journal of Plant Biology
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• v.5 no.2
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• pp.6-12
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• 1962

For the comparison with the previous paper (4) the present report deals with the absorption and metabolism of urea and other nitrogen ions in barley seedling absorbed through root. 1. The amount of nitrate in barley treated with urea reach it peak on the 8th day. NO3 on the 4th, NH4 on the 6th or 8th, respectively. 2. The ammonia content in urea group reaches its peak on the 6th day but other groups on the 4th day. The present data in the urea group show to shorten 4 days compared with that of the previous paper(4). 3. the content of total amide from the present data aare gradully increased on all of the groups during this experiment. These are agreement with the result of the previous paper (4). 4. the alcohol solution nitrogen in the urea gorup shows the similar tendency to the NaNO3 group but reaches it peak 2 days later than in the (NH4)2SO4 group. 5. The content of total nitrogen in the urea series has the lowest amount at the beginning while the richest from the 4th day after. These would be explained on that the absorption of urea is delayed and the PH in the urea solution does not change, so called "physiological neutrality". The author should like express his sincere thanks to Prof. M.J.Lee of Seoul National University for his valuable advices.e advices.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.3
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• pp.274-276
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• 1997

The effects of cecectomy on nitrogen utilization and nitrogen excretion were examined in single comb white leghorn (SCWL) cockerels fed a 5% protein diet supplied with urea. The cecectomy tended to increase nitrogen balance and nitrogen utilization and significantly decreased uric acid excretion (p < 0.01). Urea and ammonia excretion tended to be about 60% increased and decreased by cecectomy in SCWL cockerels, respectively, but blood ammonia, urea and uric acid concentrations were not affected. The results are in good agreement with those obtained previously in cecum-ligated chickens. It is concluded that the improvement of nitrogen utilization and decreases in urinary uric acid excretion in cecectomized chickens do not result from the modification of cecal fermentation.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.6
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• pp.407-412
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• 2001

This study was conducted to find out the effect of slow-release nitrogen fertilizer, such as latex coated urea(LCU) and Meister10(MS10) on direct seeded rice in dry soil(DS). Junghwabyeo, and early maturity rice cultivar was grown on the plots which were treated with None-nitrogen. urea. LCU and MS10 plot. Growth characteristic, yield and yield components were investigated. Nitrogen uptake-efficiency and physico-chemical properties of soil before-after experiment were analyzed. Plant height and number of tillers $m^{-2}$ in LCU and MS10 plot at early grow stages were higher than those in urea plot. Plant height and number of tillers $m^{-2}$ grown on the plot of Ms10 plot were higher than those of LCU plot. The number of seedling $m^{-2}$ were no significant differences among None-N, urea, and MS10 plot in DS. Heading date and leaf color were higher with Urea than LCU and MS10 plot. Culm length in LCU and MS10 plot were longer compared with urea plot, but panicle length was similar among with Urea, LCU and MS10 plot. Number of panicles $m^{-2}$ was greater in order of MS10 > LCU > Urea plot. Yield were greater in order of MS10 > LCU > Urea plot. Nitrogen uptake and nitrogen efficiency were greater in order of MS10 > LCU > urea plot. After the experiment, total content of nitrogen in soil was not changed at all treatments, but pH, P and Si of soil were lower than those of before experiment at all treatments.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.52-58
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• 1982

The effects of casein diet supplemented with excessive levels of three basic amino acidslysine, histidine and arginine - were studied in male, weanling, I. C. R. strain mice. The relationship between weight gain and concentration of blood urea nitrogen was also discussed with the follows results : 1. The groups supplemented with basic amino acids were demonstrated depressed growth and food intake than the control ($10\%$ casein diet) group, $5\%$ L-histidine HCl supplemented group being most depressed. 2. The concentration of blood urea nitrogen in the basic amino acid supplemented groups were higher than the control group. The value of L-arginine supplemented group was highest. 3. The concentration of blood urea nitrogen was related to the amounts of nitrogen contained in the diet not related to the growth gain.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.6
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• pp.401-406
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• 2001

This study was conducted to find out the effect of slow-release nitrogen fertilizer, such as latex coated urea(LCU) and Meister10(MS10) on direct seeded rice in flooded soil(FS). Junghwabyeo, and early maturity rice cultivar grown on the plots which were treated with None-nitrogen, urea, LCU and MS10 plot. Growth characteristic, yield and yield components were investigated. Nitrogen uptake-efficiency and physico-chemical properties of soil before-after experiment were analyzed. Plant height and number of tillers $m^{-2}$ in LCU and MS10 plot at early grow stages were higher than those of Urea plot. MS10 and LCU plot showed similar tendency on the plant height but MS10 plot was higher than LCU plot on the number of tillers $m^{-2}$. The number of seedling $m^{-2}$ were no significant differences among None-N, urea, and MS10 plot. Heading date and leaf color were no significant differences among None-N, urea, and MS10 plot. Culm length in LCU and Ms10 plot were longer compared with urea plot, but panicle length were similar among with Urea, LCU and MS10 plot. Number of panicles $m^{-2}$ was highest in MS10 plot and it was similar between LCU and Urea plot. Yield were greater in order of Ms10 > LCU > Urea plot. Nitrogen uptake and nitrogen efficiency were greater in order of MS10 > LCU > urea plot. After the experiment, total content of nitrogen in soil was not changed at all treatments, but pH, P and K of soil were lower than that of before experiment at all treatments.

• Journal of Embryo Transfer
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• v.16 no.1
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• pp.47-51
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• 2001

This study was done to examine the relationship between serum chemical values (urea nitrogen, glucose, total protein and cholesterol) of recipients and pregnancy rate following embryo transfer. Blood samples were taken from 184 Holstein heifers or cows on Day 6 or 7 (Day 0=day of estrus) to analysis for serum urea nitrogen, glucose, total protein and cholesterol concentrations. After selection of recipients, frozen Holstein embryos were thawed and directly transferred to recipients non-surgically. The average serum concentrations of urea nitrogen, glucose, total protein and cholesterol were 13.8 mg/dl, 56.5 mg/dl, 7.2 mg/dl, 124.8 mg/dl, respectively. The average concentrations of serum urea nitrogen and cholesterol were lower (P<0.05) in pregnant recipients (10.7 mg/dl, 99.2 mg/dl) than in non-pregnant recipients (13.0 mg/dl, 122.2 mg/dl), respectively, although the concentrations of glucose and total protein were not different. These results show serum urea nitrogen and cholesterol concentrations can be used important factors for selection of recipients in Holstein.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1583-1591
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• 2003

The influence of varying levels of urea and additives on nitrogen (N) retention and chemical composition of wheat straw was studied. The wheat straw was treated with 4, 6 and 8% urea and ensiled with 1.5, 2 and 2.5% of acetic or formic acid and 2, 4 and 6% of corn steep liquor (CSL) or acidified molasses for 15 days. The N content of wheat straw was significantly different across all treatments. The N content of urea treated wheat straw was increased with the increasing level of urea. The N content was higher in urea treated wheat straw ensiled with acetic or formic acid as compared to urea treated wheat straw ensiled without these organic acids. The N content of urea treated wheat straw was further enhanced when it was ensiled with CSL or acidified molasses. This effect was significant across all levels of urea used to treat the wheat straw. Nitrogen retention in urea treated wheat straw was decreased linearly as the urea level was increased to treat the wheat straw. The N content was increased linearly when higher levels of CSL or acidified molasses were used to ensile the urea treated wheat straw. Most of the N in urea treated wheat straw was held as neutral detergent insoluble N (NDIN). The NDIN content was increased linearly with the increasing levels of urea and additives. The neutral detergent fiber (NDF) contents were higher in urea treated wheat straw ensiled with acetic or formic acid as compared to urea treated wheat straw ensiled without additive. The NDF content further increased in urea treated wheat straw ensiled with CSL and acidified molasses. The entire increase in NDF content was because of fiber bound N. The hemicellulose content of urea treated wheat straw ensiled with CSL or acidified molasses was higher as compared to urea treated wheat straw ensiled with acetic or formic acid. The acid detergent fiber content of urea treated wheat straw ensiled with or without additives remained statistically non-significant. The cellulose contents of wheat straw was linearly reduced when urea level was increased from 4 to 6 and 8% to treat the wheat straw. This effect was further enhanced when urea treated wheat straw was ensiled with different additives. The results of the present study indicated that fermentable carbohydrates might improve the Nitrogen retention and bring the favorable changes in physiochemical nature of wheat straw. However, biological evaluation of urea treated wheat straw ensiled with fermentable carbohydrates is required.

• Journal of Plant Biology
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• v.7 no.1
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• pp.11-14
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• 1964

Change of the amount of carbohydrates in relations with nitrogen metabolism was studied under the different manners of supply and with different sources of nitrogen. In barley plant supplied with nitrogen through root, the depression periods of glucose and sucrose content occurred at 2 days after, but the amounts of both sugars were different with the different sources of nitrogen; there were in sequence diminished by treatment of NO3, NH4 and urea. In sunflower leaves sprayed with urea both sugar contents were inversely related to the urea concentration sprayed, and depressing periods of the sugars appeared immediately in the N-deficient plant but late in the N-abundant one.