• 아시안잔디학회지
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• 제11권2호
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• pp.105-115
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• 1997

Responses of 'Penncross' creeping bentgrass turf to various fairway cultural practices are not well-established or supported by research results. This study was initiated to evaluate the effects of irrigation frequency, clipping return or removal, and nitrogen rate on leaf and soil nitrogen con-tent in the 'Penncross' creeping bentgrass (Agrostis palustris Huds.) turf. A 'Penncross' creeping bentgrass turf was established in 1988 on a Sharpsburg silty-clay loam (Typic Argiudoll). The experiment was conducted from 1989 to 1991 under nontraffic conditions. A split-split-plot experimental design was used. Daily or biweekly irrigation, clipping return or removal, and 5, 15, or 25 g N $m-^2$ $yr-^1$ were the main-, sub-, and sub-sub-plot treatments, respectively. Treatments were replicated 3 times in a randomized complete block design. The turf was mowed 4 times weekly at a l3 mm height of cut. Leaf tissue nitrogen content was analyzed twice in 1989 and three times in both 1990 and 1991. Leaf samples were collected from turfgrass plants in the treatment plots, dried immediately at 70˚C for 48 hours, and evaluated for total-N content, using the Kjeldahl method. Concurrently, six soil cores (18mm diam. by 200 mm depth) were collected, air dried, and analyzed for total-N content. Nitrogen analysis on the soil and leaf samples were made in the Soil and Plant Analyical Laboratory, at the University of Nebraska, Lincoln, USA. Data were analyzed as a split-split-plot with analysis of variance (ANOVA), using the General Linear Model procedures of the Statistical Analysis System. The nitrogen content of the leaf tissue is variable in creeping bentgrass fairway turf with clip-ping recycles, nitrogen application rate and time after establishment. Leaf tissue nitrogen content increased with clipping return and nitrogen rate. Plots treated with clipping return had 8% and 5% more nitrogen content in the leaf tissue in 1989 and 1990, respectively, as compared to plots treated with clipping removal. Plots applied with high-N level (25g N $m-^2$ $yr-^1$)had 10%, 17%, and 13% more nitrogen content in leaf tissue in 1989, 1990, and 1991, respectively, when compared with plots applied with low-N level (5g N $m-^2$ $yr-^1$). Overall observations during the study indicated that leaf tissue nitrogen content increased at any nitrogen rate with time after establishment. At the low-N level treatment (5g N $m-^2$ $yr-^1$ ), plots sampled in 1991 had 15% more leaf nitrogen content, as compared to plots sampled in 1989. Similar responses were also found from the high-N level treatment (25g N $m-^2$ $yr-^1$ ).Plots analyzed in 1991 were 18% higher than that of plots analyzed in 1989. No significant treatment effects were observed for soil nitrogen content over the first 3 years after establishment. Strategic management application is necessary for the golf course turf, depending on whether clippings return or not. Different approaches should be addressed to turf fertilization program from a standpoint of clipping recycles. It is recommended that regular analysis of the soil and leaf tissue of golf course turf must be made and fertilization program should be developed through the interpretation of its analytic data result. In golf courses where clippings are recycled, the fertilization program need to be adjusted, being 20% to 30% less nitrogen input over the clipping-removed areas. Key words: Agrostis palustris Huds., 'Penncross' creeping bentgrass fairway, Irrigation frequency, Clipping return, Nitrogen rate, Leaf nitrogen content, Soil nitrogen content.

• International Journal of Industrial Entomology and Biomaterials
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• 제5권1호
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• pp.131-134
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• 2002

Mulberry being the only food of silkworm, Bombyx mori L., is of great economic importance to the silk industry, The success in cocoon production mainly depends on the supply of quality leaves in sufficient quantity. In mulberry, where the economic product is leaf, the uptake of nitrogen from soil is very heavy and high responses to application of nutrients have been reported. Nitrogen supports vegetative growth particularly the leaf biomass. Variation in nitrogen harvest index and other physiological and yield contributing traits were estimated in five mulberry genotypes. Considerable variation was observed for nitrogen harvest index, protein yield per plant and harvest index. The correlation studies indicated the protein yield per plant was significantly correlated with leaf yield, nitrogen content in leaf, nitrogen harvest index and harvest index. The broad sense heritability estimates revealed that harvest index showed highest heritability (88.07%) followed by nitrogen content (82.52%), protein yield (70.28%) and nitrogen harvest index (66.52%).

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1262-1262
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• 2001

The rice plant is one of the important staple crops in Korea. The high yield with low cost in rice is required the soil fertility and the development of new precise method of fertilizer application by nutritional diagnosis. Now, in Korea, the nitrogen application system for the rice plant is composed of the basal fertilization, fertilization at tillering stage and fertilization at panicle stage, which the nitrogen fertilization at panicle stage amount to about 30 percent in the total amount. Thus, this experiment carried out to the development of the system that can measure the nitrogen content in the rice plant at panicle stage rapidly with the near infrared spectroscopy, and to predict the appropriate quantity of the nitrogen fertilization at panicle stage based on calibration model for test of nitrogen content in rice plant. The samples were collected from 48 varieties in 4 regions which are mainly cultivated in the southern part of Korea. And then, it collected by classifying into the leaf, the whole plant and the stem since 7 days before the nitrogen fertilization at panicle stage. The ranges of the nitrogen contents were 1.6∼4.0%, 1.7∼3.0% and 1.4∼2.7% in the leaf, the whole plant and the stem, respectively. In the calibration models created by each part of the plant under the Multiple Linear Regression(MLR) method, the calibration model for the leaf recorded the relatively high accuracy. The mutual crossing test on unknown samples were carried out using Partial Least Square(PLS) calibration model. That is, the nitrogen content in the stem was tested by calibration model made by the leaf model and that of stem was tested by calibration model made by whole plant sample. When unknown leaf sample was tested by calibration model made by all sample that collected from each part in rice plant such as leaf, stem and whole plant, it recorded the highest accuracy. As a result, to test the nitrogen content in the rice plant at panicle stage, the nitrogen content in the leaf shall be tested by the calibration model composed of the leaf, the stem and the whole plant. In future, to estimated the amount of nitrogen fertilization at panicle stage for rice plant , it will be calculated based on regression model between rice yield and nitrogen content of leaf measured by calibration model made by mixed sample including leaf, stem and whole plant.

• 한국연초학회지
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• 제13권1호
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• pp.74-81
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• 1991

This study was conducted to find out physical and chemical characteristics of burley and flue-cured tobacco leaves followed by location, growing season and leaf position during the period 1985 to 1989. The locations of flue-cured tobacco were 7(65farms) and burley tobacco were 4(40 farms). 1. Flue-cured tobacco leaves The locations of Ch'unch'on and Suwon were higher nicotine and ether extract content, Taegu and Chinju were higher total nitrogen content but Chiniju was lower red color of cured leaves than that of other location. Nicotine content increased but total sugar content decreased during the period 1985 to 1989. Nicotine and total nitrogen content increased but crude ash decreased from lower leaf position to higher leaf position. Total sugar and ether extract content were variable followed by leaf position. 2. Burley tobacco leaves. The location of Ch'onju was higher ether extract content than that of others location, but there was no significant difference the others chemical component among location. Nicotine content and red color of cured leaves increased during the period 1985 to 1989. Nicotine, total nitrogen and ether extract content increased but decreased crude ash content and brightness of cured leaf from lower leaf position to higher leaf position.

• 한국연초학회지
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• 제10권1호
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• pp.3-9
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• 1988

Effect of several nitrogen fertilizer sources on the chlorine absorption by the burley tobacco plants was investigated under the field and pot condition. The nitrogen sources included compound fertilize.(containing 3.9% NH4-N and 6.1% NH2-N), (NH4)2SO4, NaNO3. (NH2)2CO and NH4NO3. The chlorine content of leaf during growing stage was high in (NH4)2SO4 plot , and the differences among nitrogen sources was remarkable at maximum growing stage. The chlorine content of cured leaf was high in (NH4)2SO4 plot. When the (NH4)2SO4 was applied, the total alkaloid content of cured leaf was increased and the color of cured leaf became undesirable with the increment of leaf chlorine. The yield, quality and value of cured leaf were high in NaNO3 plot , while low in (NH4)2SO4 plot.

• The Korean Journal of Ecology
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• 제21권4호
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• pp.329-335
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• 1998

The growth of Phytolacca L. grown under three light regimes at three nutrient concentrations was analyzed. The effect of shading treatment on plnat growth was greater than that of nutrient treatment. Plant dry mass increased more than 5-fold during 21 days under 33% and 100% irradiances, whereas that was strongly reduced under 8% irradiance. Net assimilation rate decreased with plant growth irrespective of light and nutrient treatments, though the highest net assimilation rate was shown under 100% irradiance. Under 33% irradiance leaf area in plants supplied with nutrient solution increased to such extent as to compensate reduction in net assimilation rate, whic maintains almost identical growth rate with that under 100% irradiance. The relatonship between total plant nitrogen and leaf nitrogen content was dependent on the growth irradiance. Moreover, leaf nitrogen and specific leaf weight were also changed depending on the light and nutrient conditions. Based on these findings, it is suggested that the adaptive characteristics of Pokeberry plant to light and nutrient conditions may contribute to rapid extension of Pokeberry habital in Korea rocently.

• 환경생물
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• 제24권2호
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• pp.186-194
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• 2006

Nitrogen dynamics of Seagrass Zostera marina were investigated in both Dongdae Bay and Ojiri from March to August, 2004. All seagrass samples were separated into four fractions such as leaves (new and adult), sheath and rhizome in order to understand temporal variations of nitrogen content in different fractions of Zostera marina. There are temporal variations of shoot production rates and total nitrogen contents in their different fractions at both study areas. Leaf production were almost 4 to 5 fold higher in summer than in winter. The irradiance is the primary factor controlling the leaf production of Zostera marina in both sites although water temperature also influence its productivity. Nitrogen contents of leaves were overall low in summer than in winter, but nitrogen content of rhizome increased during the summer season. In addition, nitrogen contents of new leaves were mostly higher than adult leaves in spite of lower nitrogen content of new and adult leaves in high productivity period. This result suggests that Zostera marina seems to have significant translocation ability of nitrogen in a shoot. The nitrogen content of leaf tissue may reflect nutritional nitrogen availability.

• Journal of Plant Biology
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• 제17권3호
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• pp.127-136
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• 1974

The effect of potassium metabolism on the soybean leaves was studied with comparison of other elements during the successive growing period. The results were as follows; 1. The percentage of potassium content showed remarkable increase not only in the first compound leaf at a stage which was growing vigorously and producing new leaves, but also in the fifth compound leaf at a stage which was taking a active metabolism of nitrogen and carbohydrate but not producing new leaves. However, the percentage of potassium content was decreased in the second compound leaf than in the first one. Such a result could be regarded as a potassium removal from mature leaves into immature and flowing out from stoma through respiration. During the pod-development the percentage of potassium content in the soybean leaf was decreased. 2. If nitrogen, phosphorus and potassium were added excessively in the nutrient solution, the percentage of potassium content in the soybean leaf had increased. The effects of these elements showed a remakable increase in the excessive plot of nitrogen than in that of phosphorus. At early stage the redtarded effect of phosphorus on the growth of soybean could be covered by potassium, however, at late stage it could not. The growth of soybean plant was much more inhibited by potassium, compared with nitrogen and phosphorus. New leaves could not be produced in the potassium deficient soybean plant after the third compound leaf. The normal growth of soybean plant could not be observed if only one element was excessively added to the culture solution, compared with the deficiency of other two elements.

• 한국연초학회지
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• 제26권1호
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• pp.17-26
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• 2004

This study was conducted to get the informations for reducing the variation of chemical contents of leaf tobacco. The contents and variations of some chemical constituents of leaf(Leaf, Grade 2) produced in various growing areas from 1999 to 2003 and the effects of meteorological factors on the chemical constituents of leaf were analysed. The contents of analysed constituents of leaf showed high significant differences among crop years in flue-cured and burley, particularly the variation among crop years were higher in chlorine and nicotine contents while lower in total nitrogen content. There were significant differences among growing areas in nicotine and total sugar contents of flue-cured leaf and chlorine content of burley leaf. The total sugar content were negatively correlated to the nicotine and total nitrogen contents in flue-cured leaf. The average air temperature in June and July were positively correlated to the nicotine content of leaf while negatively to total sugar, and the precipitation in May were negatively correlated to the nicotine while positively to total sugar.

• 한국연초학회지
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• 제14권1호
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• pp.48-56
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• 1992

This studies were carried out to investigate the effects of leaf loading quantity and circulating air volume during bulk curing on the variation of physical and chemical characteristics in flue-cured tobacco. The results are as follows : 1. The content of sugar in cured leaves was decreased with more circulating air volume and leaf loading quantity at bulk curing. 2. Total nitrogen and protein nitrogen were decreased with less circulating air volume and more leaf loading quantity, while amino nitrogen was increased. 3. The contents of linolenic acid and linoleic acid were increased with more leaf loading quantity and oxalic acid and citric acid had a tendency of being increased in case of high circulating air volume. 4. In general, major aromatic compounds were increased through flue-curing. Relatively high content of solanone in case of lower air volume and less leaf loading were observed, while megastig matrienone was increased when leaf loading was small. 5. The more circulation air volume with leaf loading quantity caused lowering equilibrium moisture content and higher shatter index, which resulted in poor quality of cured leaves based on quality index, nitrogen number, taste index phillips index, and sugar-nicotine ratio.