• Korean Journal of Soil Science and Fertilizer
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• v.44 no.4
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• pp.597-599
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• 2011

This study was conducted to find out the optimum nitrogen application rate for the stable production of rape in the newly reclaimed land located at Gangwhal region of Saemangum reclaimed land in which the soil is sandy loam (Munpo series). There were five treatments of nitrogen fertilization from zero to 60% increment based on the standard fertilization of $150kg\;ha^{-1}$. The growth of rape (Sunmang) was not affected by salt content while soil salinity was increased at blossoming season of rape. Compared to yield of standard fertilization the yield and the content of oleic acid of rape were increased by 4~26% with the increasing additional nitrogen fertilizer. The results obtained from the growth and yield of rape in this study indicated that it was possible to cultivate rape in a newly reclaimed land if soil salinity was kept below $3dS\;m^{-1}$.

• Journal of Korean Society of Forest Science
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• v.87 no.1
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• pp.98-105
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• 1998

We measured seedling growth, foliar nutrient and extract concentrations of 3-year-old Ginkgo biloba seedlings growing in a nursery following a single fertilization with nitrogen (N), phosphorus (P) and nitrogen plus phosphorus (N+P) fertilizers. Fertilization did not change foliage, stem and root biomass of the seedlings except for the high N+P treatment, Foliar N and P concentrations following fertilization varied according to the amount of fertilizers. In general, foliar N and P concentrations increased with fertilization, but fertilization with 400kg N/ha and 100kg P/ha decreased foliar N and P concentrations, respectively. Seedling growth and foliar nutrient concentrations showed that N and P were the growth-limiting nutrients in our study site. It was found that fertilization reduced the concentrations of secondary metabolites (Ginkgo flavon glycosides and terpene lactones) in foliages. It seemed there was a relationship between foliage biomass production and secondary chemicals in G. biloba seedlings.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.3
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• pp.358-363
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• 2011

To investigate the effect of nitrogen fertilization on the quality of tropical grass silage, guinea grass grown with 3 types of nitrogen fertilizers, namely, urea, ammonium sulfate, and compound fertilizer 804, at 2 fertilization levels, 0.5 and 2.5 kg $Na^{-1}$ (0.5 N and 2.5 N, respectively), was subjected to silage fermentation. Silage fertilized with 0.5 N showed butyrate-dominant fermentation, irrespective of the type of fertilizer used. On the other hand, fermentation of silage fertilized with 2.5 N was significantly affected by the type of fertilizer used; fertilization with ammonium sulfate and compound fertilizer 804 resulted in silage that contained a large amount of butyrate and no lactate; this silage was considered to be of a significantly low quality as compared with silage fertilized with 0.5 N. Among silage fertilized with 2.5 N, the desirable butyrate-free fermentation was found only in urea-fertilized silage, which had the best quality. Grass material fertilized with a high level of urea accumulated a relatively high concentration of nitrate nitrogen (0.22% dry matter). Our results presented here suggest that nitrogen fertilizer management could affect the quality of tropical grass silage and that a relatively high concentration of nitrate in silage may promote butyrate-free fermentation even in tropical grass silage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.14
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• pp.65-69
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• 1973

This experiment was carried out to determine the adequate amount of nitrogen for densely and lately seeded soybean, and the results obtained are as follows, 1) Various fertilization amounts of nitrogen did not effect the date of emergency, but the flowering and the maturing dates were delayed at the plots fertilized the nitrogen heavily. 2) In accordance with an increasing amount of nitrogen fertilization, the length of the stem and the internode was significantly elongated but the stem diameter was thinned down, and the latter was suggested to be the cause of lodging. 3) The 1, 000 grain weight and the number of pods per hill were decreased according to the increasing the amount of nitrogen fertilization. 4) A highly significant difference in grain yield was recognized between varieties but among treatments. However, in case of the extremly late cultivation, the grain yield of the early maturing variety (Choongbukbaeg) was increased at the plot of 6 kg nitrogen.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.6
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• pp.384-392
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• 2000

To establish N fertilizer recommended scheme for the Chinese cabbage cultivation in green house based on the soil test of nitrate nitrogen, relationship among the content of soil nitrate and fertilizer effects and fertilizer N use efficiency were investigated from nine soils which differed amount of nitrate nitrogen from $14mg\;kg^{-1}$ to$226mg\;kg^{-1}$. The amount of nitrate nitrogen in soil showed a positive correlation with the dry weight of chinese cabbage in the plot of no fertilization. When the fertilizer effects were calculated by difference between the plots of fertilization and no fertilization in the dry weight and the amount of N uptake, a negative correlation was obtained between the amount of nitrate nitrogen in soils and the fertilizer effects. There was also a negative correlation between the amount of nitrate nitrogen in soils and fertilizer use efficiency. Recommendation of application rate of nitrogen fertilizer based on content of $NO_3-N$ in soils was evaluated by the regression equation among the content of soil nitrate, fertilizer effects and fertilizer N use efficiency. Incase the content of $NO_3-N$ nitrogen in soil is more than $200mg\;kg^{-1}$, No N fertilization is recommended; However, The standard N fertilization($320kg\;ha^{-1}$) is recommended for the soils with less than $50mg\;kg^{-1}$. For the soils ranged from $50mg\;kg^{-1}$ to $200mg\;kg^{-1}$ in the amount of nitrate nitrogen, an equation has been developed in order to calculate the recommended amount of fertilizer N.

• Journal of The Korean Society of Grassland and Forage Science
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• v.12 no.1
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• pp.59-66
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• 1992

An experiment was conducted to determine the effects of seeding rates and nitrogen fertilization levels on the agronomic characteristics, nutritive value and forage yield of spring oat(Avena sativa L.). This experiment was undertaken over a period of 2 months from September to November, 1987. The results obtained are summarized as follows : Increased seeding rates of 120, 160 and 200kg/ha decreased emergence rates by 93.4, 71.4 and 70.6 %, respectively(P<0.05). Tillering was decreased by higher seeding rates(P<0.05) and that of 120kg/ha of seeding rate with 200kg/ha of nitrogen fertilization level was highest by 3.3. Among three seeding rates, tillering of 200 kg/ha of nitrogen fertilization level was lowest by 2.1. Leaf width was influenced by seeding rates. When seeding rate was increased, narrow leaf width (P

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.1
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• pp.1-6
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• 1994

This experiment was carried out to study the effect of cutting frequencies(2, 3: one time grazed after 2 cuts, 3, 4, 6 cuts per year) and nitrogen fertilization(0 and 120 kg per ha and year) on botanical composition of permanent grassland at the "Federal Research Institute for Agriculture in Alpine Regions(Gumpenstein)," Austria The results are summarized as follows: 1. With only fertilizing phosphorus(P) and potassium(K),mean annual dry matter yields were 6.9 - 8.4 ton per ha and highest when only one time grazed after 2 cuts, but fell progressively with increase in cutting frequency and additonal fertilization of nitrogen. The average nitrogen efficiences expensed as dry matter yieldsfig) per feltilized nitrogenfig per ha) were 10.3 kg. 2. When N fertilizer was applied, the proportion of tall and medium grasses in the mixed swards increased by 30 - 50% compared with only fertilizing PK. Whereas swards with fertilizing only PK generally stimulated composition of the legumes at the expense of the grasses(30 - 50%). 3. Although the proportion of tall and medium grasses(Trisetum flavescens and Dachlis glomerara) and tall herbs(hntodon hispidus, Taraxacum oflcinale and Aegopodium podagraria) increased by infrequent cutting, frequently cutting plots helped increase the proportion of short grasses(Poa pratensis and Poa trivialis), especially where plots both had been applied with nitrogen fertilizer. 4. Nitrogen fertilization resulted in higher existence of herbs and weeds such as Taramcum oficinale. Aegopodium podagraria, Galium mllugo, Anthriscus silvestris and Lamium album. 5. Due to unusually high or low cutting frequencies such as 4 cuts or 2 cuts per year increased botanical compostion of Heracleum sphondylium.hondylium.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.421-427
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• 2015

Angelica gigas Nakai is one of the most widely used herbal medicines and is known to have many pharmaceutical effects including an anti-oxidant, anti-cancer etc. This study was carried out to investigate an effect of fertilization on leaf yield, production of dry-matter and accumulation of pyranocurmarine compounds such as decursin (DE) and decursinol angelate (DA) in Angelica gigas Nakai. Effect of fertilization was determined from response surface regression equation composing of 2 by 3 factorial arrangement of urea, sodium dihydrogen phosphate and potassium chloride. Yield of leaf in Angelica gigas Nakai significantly increased until 100 days after transplanting. Production of leaf also tended to increase with increasing nitrogen fertilization. Model of regression equation showed that leaf production depended upon nitrogen ($Pr>{\mid}t{\mid}$ : 0.087, 0.256 and 0.079). Also, statistical results between nitrogen application level and production of dry-matter showed significant relationship (p<0.05) and contents of dry-matter was highest in 10 kg 10a-1 treatment on 24 Sep. Active compound isolated and purified from leaf and root of Angelica gigas Nakai was identified as DE and DA by gas chromatograph-mass spectrophotometry (GC-MS). Concentration of DA as prevalent compound in leaf was highest on 20 Aug. but decreased on 24 Sep. Amount of DE and DA accumulated in Angelica gigas Nakai significantly increased with growth stages and nitrogen level. The result of our investigation imply that nitrogen fertilization is important factor for production of leaf and accumulation of pyranocurmarine in Angelica gigas Nakai as a medicinal/food materials.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.5
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• pp.340-346
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• 2000

This experiment was conducted to investigate the effect of nitrogen fertilization in job's tears (Coix lachryma-jobi L.) on the growth characteristics, grain yield, nitrogen accumulation, and chemical property of soil after harvest. Heading and budding stages were shorter than control but growth periods was increased because of the increase of ripening periods according to the increase of nitrogen fertilizer applications. Number of main culm node and culm diameter was similar but culm length and tiller number per plant were better according to the increment of nitrogen fertilizer applications than control but the decrease of grain yield was attributed to the fact that damage by corn borer was 30% in $240kg\;ha^{-1}$ of nitrogen treatment. Some of yield components was better according to the increment of nitrogen fertilizer applications but grain number per plant of $160kg\;ha^{-1}$ of nitrogen treatment was greater. So grain yield was the highest ($3,410kg\;ha^{-1}$) at the $160kg\;ha^{-1}$ of nitrogen fertilization. Nitrogen use efficiency decreased according to the increase of nitrogen fertilization. Total nitrogen of soil after experiment in 0, $80kg\;ha^{-1}$ of nitrogen treatments was lower and in 160, $240kg\;ha^{-1}$ of nitrogen treatments was higher than that before the experiment.

• Weed & Turfgrass Science
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• v.3 no.2
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• pp.137-142
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• 2014

This study was conducted to investigate the effect of silicate mixed with nitrogen fertilizer on improving the growth and reducing nitrogen input of zoysiagrass. Plant height, fresh and dry weight of shoots, roots, and stolons, the number of shoots and total of stolons length were increased with highest in silicate mixed with nitrogen 24 kg/10a than nitrogen 24 kg/10a, and it showed no significance in silicate mixed with nitrogen 18 kg/10a. Nitrogen use efficiency in mixed silicate fertilizer was increased by 25-30% than single nitrogen fertilization. Moreover, the contents of available $SiO_2$, and organic matters of silicate fertilization on soil was higher than not silicate fertilization on soil. The silicate enhanced the growth and density of zoysiagrass, while it was a crucial factor to affect the chemical property of the soil.