• 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 Agricultural Engineers
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• v.60 no.3
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• pp.107-112
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• 2018

In this study, we conducted to analyze and quantify the amount of nitrogen supply into the rice paddies from the rainfall during cropping and non-crop periods. Rainfall monitoring conducted 85 times from June 2015 to December 2017. Nitrogen supply of cropping season ranged from 5.37 to 7.70 kg/ha, while non-cropping season were supplied from 3.97 to 4.42 kg/ha. The supply of T-N in the crop period was more than 60% of the total supply. And as a result of analyzing the correlation between the characteristics of rainfall and the supply amount, nitrogen concentrations in rainfall were decreased with increasing rainfall, but the supply amount was increased. Therefore, efforts should be made to increase the rainfall utilization and to increase the nitrogen supply of crops by increasing rainfall storage through drainage management.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.1
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• pp.96-102
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• 1981

Effect of shifting planting-time and different nitrogen on the yield and characteristics of plant growth in safflower, Chrthamus Tinctorius L. This study was carried out to investigate the optimum sowing-date and the ecological variations due to differerent amount of nitrogen for safflower on the Experiment Farm of Sang Ji college from March 17 to may 16, 1980, sowing seeds with an interval of 10 days and the amount of nitrogen were applied in 5 levels (Non, half-standard, standard, one and half-ordinary amount-No and twice amount). The triple super phosphate and pottassium chloride were applied only in standard amount. The results obtained are summarized as follows; 1. As sowing-date was delayed, the germination-ratio decreased, germinating speed increased, and the time required to attain the most vigorous germinating stage and days required for germination shortened. 2. Plant height, number of branch and stem diameter showed a decrease as sowing-date was delayed. And at the same time, plant height and number of branch showed a tendency to increase as amount of nitrogen was increased. 3. As sowing-date was delayed, the number of pods and the weight of 1000-grains were decreased. Moreover, the earlier sowing-date was, the more it increased. And as amount of nitrogen was increased, number of pods and yield also were strikingly increased. 4. The fresh-weight of flower with orange and orange-red colour, as influenced by the different sowing-date, was found out to be largest at the begining of April. But increasing amount of nitrogen did not show influence upon the promotion of flowering. 5. Judging from the results reported above, the optimum sowing-date of safflower seemed to be the begining of April; also the culture of safflower seemed to be the effects of much amount of nitrogen.

• Korean Journal of Plant Resources
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• v.20 no.2
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• pp.129-132
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• 2007

It summarize result that test 3 years since 2002 allowing back 4 processing for disregard to supply basis data of method of cultivation establishment examining raw meat and quantity by the nitrogen additional fertilizer amount after Saururus chinensis 1th harvesting, is as following, Plant height, size of leaf, Stem diameter, water saving, goods leave, foliar such as the number of tillering and growth of rhizoma are good by long or, thick or, many tendency the nitrogen additional fertilizer using as a trial amount is much after the first harvesting. When foliar amount uses 158 kg/10a provision for disregard 3, 6, 9kg/10a because is increased the nitrogen additional fertilizer using as a trial amount is much night watch, each 20%, 42%, 60% rose, Rutin of constituent content was augmented tendency nitrogen additional fertilizer amount used is much, and quercitrin is high more or less in nitrogen additional fertilizer 3kg/10a using as a trials.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.384-390
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• 2015

Remote sensing can be used to provide information about the monitoring of crop situation. This study was conducted to estimate the amount of nitrogen present in paddy fields by measuring the amount of nitrogen in hairy vetch using an UAV (Unmaned Aerial Vehicle). NDVIs (Normalized Difference Vegetation Index) were calculated using UAV images obtained from paddy fields in Seocheon on May $14^{th}$ 2015. There was strong relationship between UAV NDVI and the amount of nitrogen in hairy vetch ($R^2=0.79$). Spatial distribution maps of green manure nitrogen were generated on each paddy field using the nitrogen-vegetation index relations to help farmers determine the amount of N fertilizers added to their rice fields after the application of green manure such as hairy vetch.

• Journal of Plant Biology
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• v.18 no.3
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• pp.101-108
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• 1975

The nitrogen economy and primary production of a Helianthus annuus "Manchurian" population were studied with special reference to the pattern of seasonal changes of vertical distributions of dry matter and nitrogen quantities, and its quantitative significance was discussed in relation to the pattern of the plant population growth, distribution ratios among organs, and turnover rates of dry matter and nitrogen. The population was established in plant density of 11.1plant/$m^2$ at the experimdntal field of Kyungpook National University, Daegu. During the period of population developemnt (April-September, 1973), the annual inflow rates and outflow rates of dry matter and nitrogen were 5560 gDM/$m^2$/year and 89 gN/$m^2$/year, respectively. The distribution ratios of dry matter and nitrogen to leaves were 28% and 45%, to stems 48% and 18%, to roots 13% and 5%, and to flowers and seeds 11% and 32%, respectively. The maximum turnover rates of inflow of dry matter and nitrogen were attained in May-June, and were 216%/month and 210%/month, respectively. The amount of nitrogen demand was 52gN/$m^2$/year (58%) for the foliage growth, 13 gN/$m^2$/year(15%) for the stem growth, 20 gN/$m^2$/year(23%) for the reproductive organs, and 4 gN/$m^2$/year(4%) for the growth of the underground parts. The amount of nitrogen supply by the nitrogen withdrawn from senescing leaves and stems was 25gN/$m^2$/year(28%) and the amount of nitrogen absorption by the root from the environmental soil was 64 gN/$m^2$/year(72%). The ratiio of the a mount of produced dry matter to that of assimilated nitrogen during a year was calculated for this annual plant population as 60, which can be used as the nitrogen utility index.ity index.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.5
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• pp.253-263
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• 2002

To test for the effect of applied fertilizer and nutrients on uptake and transport for paddy rice, two paddy field trials were conducted with Dongjinbyeo in degenerated salt paddy field of Jeonbuk series from 1999 to 2000. After experiment, soil acidity, content of organic matter phosphate, silicate, potassium, calcium, and total nitrogen was increased by application of fresh cattle manure(FCM). Content of Nitrogen in soil layer leached inorganic nitrogen $NO_3$ was higher that that of $NH_4$ and was high in treatment of FCM. Content of $PO_4$ was higher in FCM than other treatments. But content of potassium was in high control. During the growth of rice plant, the amount of water consumption was 477mm. The amount of supplied nitrogen was high in treatment of no nitrogen(NN), 20% reduced application of LCU(LCU-20%), and no fertilizer. In case of phosphate, the supplied amount was more than the consumed amount with the exception of treatment "no phosphate(NP) and no fertilizer(NF)". In case of potassium, the consumed amount was more than the supplied amount in all treatments. The amount of applied nitrogen in the nutrient infiltrated water was high in treatment soil test(ST), C+FCM+Si(Silicate) and the ratio of recovered nitrogen was high in 20% reduced application of LCU. The amount of applied phosphate in the nutrient infiltrated water was high in FCM and that of applied potassium was high in 20% reduced application of LCU. Nitrogen use efficiency of paddy rice was high in 20% reduced application of LCU and use efficiency of phosphate and potassium was high in C+Si(Silicate). Grain yield of rice was high in order of 20% reduced application of LCU>C+Si=C+FCM+Si>C+FCM.

• Korean Journal of Soil Science and Fertilizer
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• v.7 no.3
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• pp.147-154
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• 1974

Relationship among grain yield (Y) nitrogen efficiency (E) and nitrogen uptake amount (N) was investigated using the data from Korea and Japan in order to find out the way of increase nitrogen efficiency. The relationship between E and N could be grouped in various classes. In each class the equation. Y=EN=(b-aN)N, is valid where b is a theoretical maximum of E and a is the E/N at theoretial maximum yield. Present technique for high yield in the rice research seems to achieve 56.8 of nitrogen efficiency with 15.5kg of nitrogen uptake. Future target appears to be 63 of efficiency with 17kg of nitrogen uptake at which some farmers in Japan might reach already. It seems that the increase of nitrogen uptake for high yield is restricted without increase of nitrogen efficiency. The increase of efficiency and uptake amount of soil nitrogen seems essential to increase total nitrogen efficiency.

• Korean Journal of Plant Resources
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• v.5 no.1
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• pp.57-68
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• 1992

The effects of various kind and amount of nitrogen fertilizers on the plant grorth. physiological , yield and extracts. ligustilide, butylidene phthalide contents of curdsdrug "Tou-ki" (AnTelica acutiloba Kitagawa) were investigated in 1989. Five plots variouskind of nitrogen fertilizers. Namely, no nitrogen, urea. ammonium nitrate, ammoniumchloride and control plot of ammonium sulfate. The other, by providing five plotsdifferent composed ratio of nitrogenous fertilizers. containing no nitrogen (No. o) .0.5-fold nitrogen (No s), control plot of 1.0-fold nitrogen(Nl.o). 1.5-fold nitrogen(Nl s)and 2.0-fold nitrogen Na. o), but nitogen was used the ammonium sulfate. The results showedthat the crude drug "Tou-ki" can ammonium chloride be produced in good yield, displayingboth good plant growth and remarkable physiologically-active conditions, and it can beproduced such that the extracts is maximized. Additionally, using methods of gaschromatography (GC) , it was established that ligustilide and butylidene phthalide, majorcomponents in the crude drug was recovered in a good yield from the fully grown plants.The other, the plant growth, the physiologically-active, the weight of whole plant, theyield of extracts and ligustilide, butylidene phthalide were seen to be best at the plotof 2.0-fold nitrogen and according to the increase or decrease of nitrogen decreasedgradually. Therefore. about 2 fold of standard quantity seems to be the most suitablequantity of nitrogen for "Tou-ki" cultivation .uot;Tou-ki" cultivation .ion .