• Applied Biological Chemistry
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• 제9권
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• pp.125-147
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• 1968

This experiment was carried out as a part of the studies on reasonable application of nitrogen in rice plant to determine: (I) Nitrogen absorption. and rooting of rice seedlings as affected by urea foliar application at late seedling stage (II) Effect of leaf prunning and foliar application of urea at late heading stage on the maturation and yield of rice (III) Effect of foliar application of urea and its time during the stage of ear formation on yield of rice plant. Results obtained are summarized as follows. Exp.I: Nitrogen absorption and rooting of rice seedlings as affected be urea foliar application at late seedling stage. 1 : The foliar application of urea plots$(T_{1},T_2)$ snowed mare N-content than non-urea foliar application plot(T0) at lane seedling stage, being significant among treatments and foliar application of urea seemed more effective in increasing the N-content of seedlings. and promoted root settlement and early growth alter the transplanting. 2 : The carbon contents of the plants of $T_1$, and $T_2$ at late seedling stage increased than T0, and the carbon contents. of $T_1$ and $T_2$ plots became higher in amount in proportion to the nitrogen absorption as compared with those of $T_0$. 3 : C/N ratio appeared significant among soil application plots($N_1, \;N_2$) and foliar application of urea plots ($T_1$, $T_2$ and $T_0$). C/N ratio was lower in case of increased amount of nitrogen. The higher contents of nitrogen and carbon and lower C/N ratio resulted in the increment of root numbers and root lengths. Exp.II: Effect of leaf prunning and foliar application of urea at late heading stage on the maturation and yield of rice. 1 : There was a highly significant decrease in the maturing rate by severe leaf prunning. In the mean time, significant increase in maturing rate was observed with urea foliar application and it was found the more frequent application the more effective for higher maturing rate with a moderate significance. A correlationship between the level of prunning and maturing rate was enumerated to 0.961 of correlation coefficient, which indicated an increased maturing rate by the increased number of remaining leaves. 2 : The 1.000 grain weight, grain weight and hulled rice yield increased by leaf prunning in order (plot a$A_1$, $A_3$, $A_2$ and $A_0$ were 89.8%, 89.4%, 87.8% and 87.5% respectively, showing the highest of rate in $A_1$ and $A_3$ in methods of ear fertilization and being highly significant between its treatment. 3 : 1000 grain weights were highly significant between time of application, showing a tendency of increase of weights with the time lagging until days before earings as that of maturing rates. High significance was recognized between methods of ear fertilization, showing the highest in $A_2$ 23.18 gr. 4 : Yields per $3.3m^2$ were not significant between time of ear fertilization, whereas were highly significant between methods of ear fertilization. Those of $A_1$, $A_3$, $A_2$ and $A_0$ were 1.486 kg, 1.491 kg, 1.381 kg and 1.328 kg, respectively, showing the highest in $A_1$ and $A_3$. 5 : Hulling ratios showed significant different between time of ear fertilization, showing the highest in $T_2$, whereas those of methods of ear fertilization were highly significant between its treatment, Those of $A_1$, $A_3$, $A_2$ and $A_0$ were 84.72%, 84.06%, 83.29%, and 82.56% respectively, showing the highest m $A_2$ and $A_3$ among others. 6 : Yields of hulled rice per $3.3m^2$ showed significant different between time of ear fertilization, showing the highest in $T_1$ 1.192 kg. Whereas, those were highly significant between methods of ear fertilization. Those of $A_1$, $A_3$, $A_2$ and $A_0$ were 1.259 kg, 1.254 kg, 1.149 kg and 1.095 kg, respectively, showing the highest in $A_1$ and $A_2$. 7 : Contents of nitrogen on rice plant increased in case of nitrogen application as ear fertilizer and showed that the case of urea foliar application was more effective than that of soil application, showing the increased nitrogen content of rice plant was accompanied by carbon content.

• Korean Journal of Medicinal Crop Science
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• 제7권2호
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• pp.101-106
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• 1999

These studies were carried out to investigate the quality of green tea processed by different 1st-pan-firing time and to select the best conditions of green tea processing. The results were as follows. At harvesting tea plant leaf, tea plants had 4 leaves, each leaf size was $6.4cm\;{\times}\;2.4cm$, and weight of 100 buds was 40.2g. The content of moisture of green tea was decreased with the prolongation of 1st-pan-firing time, and the yield of green tea at 10 min. pan-firing time was the highest value of 20.12%. After processing green tea, 1st 10 min. pan-fired one had much more contents of total nitrogen(TN 5.41%) and total amino acid(T.A.A; 3,282mg/100g) and less content of tannin(13.22%) and caffeine(1.64%) than the other treatments. The content of chlorophyll and vitamin C went down with the extension of 1st pan-firing period. Sixteen kinds of free amino acid including theanine as a good taste component of green tea were isolated and measured by HPLC. T.A.A contents were in the range of $2,447{\sim}3,192mg/100g$ and among various pan-firing methods, 10 min. 1st pan-fired one had the highest content of T.A.A. The taste-determinants such as theanine, aspartic acid, serine, glutamic acid and arginine in green tea liquor, occupied as much as $89.4{\sim}90.0%$ of T.A.A.s. Among these, theanine was more than 50%, Lightness and yellowness of green tea were increased with delay of pan-firing time, while green color appeared to be more distinct at 10 min. 1st pan -firing time than other treatments. Besides, it gained the highest score of sensory evaluation among them. These above results suggested that 10 min. pan-fired green tea was considered to be the best level as pan-firing time of green tea processing.

• Korean Journal of Soil Science and Fertilizer
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• 제2권1호
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• pp.53-68
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• 1969

The nutriophysiological response of rice plant to root environment was investigated with eye observation of root development and rhizosphere in situation. The results may be summarized as follows: 1) The quick decomposition of organic matter, added in low yield soil, caused that the origainal organic matter content was reached very quickly, in spite of it low value. In high yield soil the reverse was seen. 2) In low yield soil root development, root activity and T/R value were very low, whereas addition of organic matter lowered them still wore. This might be contributed to gas bubbles around the root by the decomposition of organic matter. 3) Varietal difference in the response to root environment was clear. Suwon 82 was more susceptible to growth-inhibitine conditions on low-yield soil than Norin 25. 4) Potassium uptake was mostly hindered by organic matter, while some factors in soil hindered mostly posphorus uptake. When the organic matter was added to such soil, the effect of them resulted in multiple interaction. 5) The root activity showed a correlation coeffieient of 0.839, 0.834 and 0.948 at 1% level with the number of root, yield of aerial part and root yield, respectively. At 5% level the root-activity showed correlation-coefficient of 0.751, 0.670 and 0.769 with the uptake of the aerial part of respectively. N, P and K and a correlation-coefficient of 0.729, 0.742 and 0.815 with the uptake of the root of respectively N.P. and K. So especially for K-uptake a high correlation with the root-activity was found. 6) The nitrogen content of the roots in low-yield soil was higher than in high-yield soil, while the content in the upper part showed the reverse. It may suggest ammonium toxicity in the root. In low-yield soil Potassium and Phosphorus content was low in both the root and aerial part, and in the latter particularly in the culm and leaf sheath. 7) The content of reducing sugar, non-recuding sugar, starh and eugar, total carbohydrates in the aerial part of plants in low yield soil was higher than in high yield soil. The content of them, especially of reducing sugar in the roots was lower. It may be caused by abnormal metabolic consumption of sugar in the root. 8) Sulfur content was very high in the aerial part, especially in leaf blade of plants on low yield soil and $P_2O_5/S$ value of the leaf blade was one fifth of that in high yield soil. It suggests a possible toxic effect of sulfate ion on photophosphorization. 9) The high value of $Fe/P_2O_5$ of the aerial part of plants in low yield soil suggests the possible formation of solid $Fe/PO_4$ as a mechanical hindrance for the translocation of nutrients. 10) Translocation of nutrients in the plant was very poor and most nutrients were accumulated in the root in low yield soil. That might contributed to the lack of energy sources and mechanical hindrance. 11) The amount of roots in high yield soil, was greater than that in low yield soil. The in high-yield soil was deep, distribution of the roots whereas in the low-yield soil the root-distribution was mainly in the top-layer. Without application of Nitrogen fertilizer the roots were mainly distributed in the upper 7cm. of topsoil. With 120 kg N/ha. root were more concentrated in the layer between 7cm. and 14cm. depth. The amount of roots increased with the amount of fertilizer applied.

• Korean Journal of Soil Science and Fertilizer
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• 제16권3호
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• pp.235-241
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• 1983

Major cation uptake by the rice plant and its leachates in submerged condition were studied at 3 different levels of potassium and nitrogen application with three texture soils (Clay loam, Loam, Sandy loam) by pot experiment. The results are as follows. 1. Potassium uptake and grain yields of rice plant were increased and calcium and magnesium uptake of rice plant were decreased by application of potassium. 2. The potassium application caused to increase Ca, Mg, K and $NH_4$ Content in leachate. 3. In the rice leaf at heading stage, the optimum cation ratios of K/Ca, K/Mg in me and $K_2O/N$ in % at N 3.3g/pot level were 1.59, 4.26 and 3.62, respectively, but the ratios were increased to 1.65, 4.32 and 3.94 at high level of nitrogen. 4. Similar trends of cation ratios were found in rice straw. leaching soil solution and soils after harvest by potassium application.

• Journal of Korean Society of Forest Science
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• 제85권3호
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• pp.416-425
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• 1996

Aboveground biomass, distribution of N and P in tree components, forest floor and the top 20cm of mineral soil, and litterfall were determined in adjacent 37-year-old plantations of Pinus rigida Mill. and Larix leptolepis Gord. on a sandy clay loam soil in Yangpyeong, Kyonggi Province. Total above-ground tree biomass for P. rigida and L. leptolepis were 138.2 and 127.2 t/ha, respectively, and did not differ between the two species. Nitrogen concentrations in stembark and foliage were all greater in L. leptolepis. Understory biomass contributed less than 2.0% of the total aboveground biomass but contributed up to 12.0% of the aboveground nutrient contents. Soil below L. leptolepis had higher concentrations of N and P. Total ecosystem N content (kg/ha) was greater for L. leptolepis (5,579) than P. rigida (4,147). Litterfall dry mass (kg/ha/yr) was greater for P. rigida (6,020) than L. leptolepis (4,191) whereas N contents in leaf litterfall (kg/ha/yr) was almost twice as large in L. leptolepis (28) than P. rigida (16). This common garden experiment suggests a strong influence of tree species on nutrient distribution and cycling in a forest ecosystem.

• Korean Journal of Soil Science and Fertilizer
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• 제15권4호
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• pp.233-240
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• 1982

This study was conducted to elucidate the translocation pattern of photosynthate labelled by $^{14}C$ in rice cultivars and the effects of nutrient composition on the translocation in rice plant during ripening, Showing coincidence between the grain filling rate and the translocation of $^{14}C$ into the grain during ripening period, the translocation patterns of cultivars tested were grouped by three; 1) the late dominance type (Akibare), 2) the early dominance type (Taebaegbyeo, Chupungbyeo), and 3) the semi-late dominance type (Milyang #23, Milyang #42, and Yushin). The negative relation ship existed between the translocation ratio of $^{14}C$ into the grain and the nitrogen content in plants, but not significant, The nutrient depletion of P, K, Ca, Mg, and Si in water medium from the panicle initiation to the heading stage resulted in the decrease of grain weight by 4 to 12 percent and the increase of translocation of $^{14}C$ into grain assimilated at heading. The effect of resupply of these nutrients after heading was recognized by the order of P>Mg>K and Ca. But the effect of Si resupply was hardly recognized in increasing grain weight. The photosynthetic rate was greatly affected by the nitrogen status and the depletion of P, K, and Ca decreased the photosynthetic rate in single leaf at heading, while the depletion of Si enhanced the rate.

• Korean Journal of Environmental Agriculture
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• 제27권4호
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• pp.428-434
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• 2008

The objective of this study is to investigate the effect of the level of $CO_2$ (370 and $650{\mu}mol\;mol^{-1}$) and temperature (ambient and ambient+$5^{\circ}C$) on tomato growth and fruit characteristics as affected by the application rate of N-fertilizer (68 and $204\;N\;kg\;ha^{-1}$), for the purpose of evaluating the influence of elevated $CO_2$ and temperature on tomato crop. The elevated atmospheric $CO_2$ and temperature increased the plant height and stem diameter for tomato crop, while the differences among the nitrogen(N) application rates were not significantly different. Under the elevated $CO_2$, temperature, and a higher N application rate, the biomass of aerial part increased. The fruit yield showed the same result as the biomass except for the elevated temperature. The elevated temperature made the size of fruit move toward the small, but the elevated $CO_2$ and the application of N-fertilizer were vice versa. The sugar content and pH of fruit juice were affected by nitrogen application rate, but not by the elevated $CO_2$ and temperature. These results showed that both the elevated $CO_2$ and temperature stimulated the vegetative growth of aerial parts for tomato, but each effects on the yield of fruit showed an opposite result between the elevated temperature and $CO_2$. In conclusion, the elevated $CO_2$ increased tomato yield and the ratio of large size of fruit, but the elevated temperature did not. Therefore, to secure the productivity of tomato as nowadays in future environment, it will need to develop new breeder as high temperature-tolerable tomato species or new type of cropping systems.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제25권1호
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• pp.1-7
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• 1980

In 1976, a newly released rice variety, Yushin, was planted in 300,000 ha of the 533,000 ha of cultivated total hecterage with new rice varieties. High productivity and quality were achieved by farmers around country. However, the wilting phenomena of Yushin occured in some regions where were employed poor cultural management, and flowed sewage into the paddy field from industrial factories. This study was identified some factors for the wilting phenomena of Yushin rice variety in morphological and physiological aspects. The Yushin variety showed greater internode elongation on low part of the stems that close related to lodge at heavier nitrogen levels, excessive number of spikelets per unit leaf blade weight i.e. higher sink/source ratio, and greater consumption of respiratory substrate by increased respiration rate of rice plant as compared with those of Tongil rice variety. In physilogical aspects, the Yushin variety was significantly declined root development and root activities under heavy nitrogen conditions. Yushin rice variety was decreased $K_2$O/N ratio, carbohydrate content in stem of rice plant, and physiological root activities specially in low light intensity, 50% light interception plots. Therefore, above factors were mainly promoted the wilting phenomena of Yushin rice variety.

• Korean Journal of Soil Science and Fertilizer
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• 제38권1호
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• pp.38-44
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• 2005

In addition to the variation in nitrate accumulation of vegetables due to environmental conditions, there is also a distinct genetic variation. The variation of nitrate accumulation in some cultivars of lettuce and spinach commonly cultivated in Korea was investigated. Ten cultivars for both lettuce and spinach were grown in plastic containers filled with a 1:1 mixture of perlite and vermiculite with application of Hoagland No. 2 nutrient solution of high nitrate content (17.3 mM N) in a greenhouse condition. Plants were harvested four weeks after transplanting four-leaf stage seedlings. Plant growth was measured by fresh and dry matter of shoot, and contents of nitrate and other inorganic ions and organic solutes including sugar, amino acids and organic acids were measured. Large and significant genotypical variations in the nitrate content of the plants were found for both lettuce and spinach, and high negative correlations between nitrate content and fresh or dry weight were found in lettuce and spinach. Variation in nitrate accumulation of lettuce and spinach cultivars was not directly related to the differences in contents of organic and inorganic solutes, and this result indicates that photosynthesis and osmotic regulation are not directly related with the nitrate accumulation. Considering the correlations between nitrate content and plant growth of this study, it can be simply suggested that different cultivars of lettuce and spinach have their own inherited growth and physiological characteristics and also optimum nitrogen level required for the growth. Therefore when available nitrogen in root media is higher than the optimum level required for the inherited growth potential, some of the excess nitrate supplied can be accumulated in plants.

• Korean Journal of Soil Science and Fertilizer
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• 제20권2호
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• pp.107-113
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• 1987

A pot experiment was carried out using Seomjinbyeo to investigate the effects of some sulfur-containing substances on the growth of rice plants and on soil characteristics. The results are summarized as follows: 1. Soil pH in plots given the sulfur treatments was lower than that in the urea plot during the growing stages. Soil pH in plots given the mineral sulfur treatments was higher than that in the ammonium sulfate plot at the early growth stage of rice. However, as the stage of rice growth progressed, soil pH became similar. After the experiment, soil pH was higher, but the sulfur content of soil was lower in the urea plot compared with that in other sulfur plots. After the experiment, the sulfur content of soil in the ammonium sulfate plot was the lowest among the plots given the sulfur treatments. 2. Plant heights and the number of tillers of the rice plants in plots given the sulfur treatments were higher than those in the urea plot, specially in the number of tillers of the rice plants. 3. Nitrogen and sulfur contents of the tops of rice plants in plots given the sulfur treatments were slightly higher than those in the urea plot. nitrogen and sulfur contents in the ammonium sulfate plot were higher than those in plots given the mineral sulfur treatments at the early growth stage of rice. However, as the stage of rice growth progressed, those in plots given the mineral sulfur treatments were higher. 4. The chlorophyll content in the leaf blade at heading stage in plots given the gypsume and given the mineral sulfur treatments was significantly higher than that in the urea plot. The N/S ratio was negatively correlated with the chlorophyll content.