• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.616-623
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• 2010

Plant samples from 49 sites for Chinese cabbage, 28 sites for radish, 16 sites for cabbage, 8 sites for head lettuce, 20 sites for onion from farmers' and experimental fields in highland of Korea were collected and analyzed to find out the uptake patterns of nitrogen (N), phosphorus (P) and potassium (K) by altitude. Dry weight and uptake of N, P and K were increased at higher altitude in most vegetable crops. Nutrition uptake by Chinese cabbage was 163 ~ 283 kg $ha^{-1}$ for N, 42 ~ 69 kg $ha^{-1}$ for $P_2O_5$ and 146 ~ 270 kg $ha^{-1}$ for $K_2O$ according to altitude. Nutrient uptake by radish according to altitude was 153~159 kg $ha^{-1}$ for N, 38 ~ 46 kg $ha^{-1}$ for $P_2O_5$, and 151 ~ 185 kg $ha^{-1}$ for $K_2O$. In case of cabbage, the plant uptakes of N, P, and K were increased at altitudes of 600 ~ 1,000 m. Nutrient uptake of cabbage was 280 ~ 348 kg $ha^{-1}$ for N, 34 ~ 87 kg $ha^{-1}$ for $P_2O_5$, and 209 ~ 290 kg $ha^{-1}$ for $K_2O$ according to altitude. Uptakes of N-$P_2O_5-K_2O$ by head lettuce at an altitude of 800 ~ 850 m were 93-26-126 kg $ha^{-1}$, respectively. Uptakes of N-$P_2O_5-K_2O$ by onions at an altitude of 600 ~ 800 m were 313-140-234 kg $ha^{-1}$, respectively, but there was no tendency in nutrition uptake patterns by altitude. Small cultivation areas used for leaf vegetable crops do not have fertilizer recommendation standards in alpine regions. It might be preferable to use a correction factor equivalent to the index of available nutrient uptake for the determination of N, P and K fertilizer application rates.

• Journal of Applied Biological Chemistry
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• v.57 no.4
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• pp.331-336
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• 2014

Sediment and nutrient loading caused by the forest to conversion of agricultural lands have led to the deterioration in near water ecosystem. This study was carried out to examine the effects of agroforest culture field and open field culture field on water quality and runoff loading of nutrient. The runoff loading of Tot-N and Tot-P in agroforest culture field were similar to open field culture field. The runoff loading of total suspended solids (TSS) in agroforest culture field and open field culture field were $2,721kg{\pm}196/10a$ and $420{\pm}29kg/10a$ in 2011 and $696kg{\pm}59/10a$ and $463{\pm}36kg/10a$ in 2012, respectively. Our investigation showed that the runoff loading of TSS from agroforest culture field decreased when soil cover and soil stabilization increased. Therefore, protect facility of soil erosion for early alteration of agricultural lands are needed to minimize the soil erosion from agroforest culture field.

• Korean Journal of Remote Sensing
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• v.34 no.5
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• pp.829-846
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• 2018

Crop monitoring can provide useful information for farmers to establish farm management strategies suitable for optimum production of vegetables. But, traditional monitoring has used field measurements involving destructive sampling and laboratory analysis, which is costly and time consuming. Unmanned Aerial vehicle (UAV) could be effectively applied in a field of crop monitoring for estimation of cultivated area, growth parameters, growth disorder and yield, because it can acquire high-resolution images quickly and repeatedly. And lower flight altitude compared with satellite, UAV can obtain high quality images even in cloudy weather. This study examined the possibility of utilizing UAV in the field of crop monitoring and was to suggest the application method for production of crop status information from UAV.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.273-281
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• 2013

Based on the results of continuous flux measurements at the Gimje paddy flux site in the southwestern coast of Korea, carbon dioxide and energy exchanges between customarily cultivated rice-barley double cropping paddy field and the atmosphere during the 2012 rice growing season (from $9^{th}$ Jun. 2012 through $20^{th}$ Oct. 2012) were analyzed. Carbon dioxide and energy (H, LE) fluxes were estimated by the eddy covariance method. Environmental parameters (net radiation, precipitation, etc.) and plant biomass (LAI, plant height, etc.) were measured along with fluxes. After the quality control and gap-filling, the observed fluxes were analyzed. The results have been showed that net ecosystem exchange (NEE), gross primary production (GPP), and ecosystem respiration (Re) during the rice cropping period were -277.1, 710.3, and 433.2 g C $m^{-2}$, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.6
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• pp.486-491
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• 2009

To evaluate the potential value of the major bioenergy crops which are wheat, canola, barley, corn, and sweet potato in Korea, we investigated the production of biomass and calorific value of crops, and also compared input and output factors among bioenergy crops during the cultivation period. There was difference between the biomass values in Agricultural and Forestry statistical yearbook(2006) and the one investigated in this experiment, also there was difference in crops and in species. Among the crops investigated, sweet potato(Jinhongmi, Yulmi) was shown the highest amount of biomass production and corn(Gangdaok) was shown the highest amount of the total biomass which is the total aboveground biomass at harvest. Oilseed canola which is presently a major source of bio-diesel had highest calorific value as $6,673{\sim}6,725cal\;g^{-1}$. Wheat and corn grains which are source of bio-ethanol were in the range of $3,879{\sim}4,317cal\;g^{-1}$. Gangdaok(Corn) produce the highest total calorific value in unit cultivating area among the crops as $8,263kcal\;m^{-2}$. Corn was shown that the input and output factors were the highest level among bioenergy crops during cultivation period. Sweet potato also was shown that output factor was the highest level though its input factors were average level. It is needed to be investigated more crops for collecting the higher potential value of bioenergy production further considering small land area and its effective utilization in Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.spc
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• pp.47-52
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• 2008

This study was carried out to improve the rice grain quality of Ilpum cultivar, especially to reduce the chalky rice rate by controlling top dressing of nitrogen application ratio at the tillering and panicle initiation stage. In the rice plant growth, the number of tiller and leaf area index of maximum tillering stage were influenced by basal dressing and top dressing at tillering stage; however those of heading stage were mainly influenced by top dressing at panicle initiation stage. In yield and yield components, they were influence by the top dressing at panicle initiation stage and the rice yield was increased by percentage of the top dressing. The protein content of rice grain was increased as the rate of top dressing at panicle initiation stage was increased. The rate of chalky and damaged rice was remarkably increased as the top dressing ratio was increased, resulting in reducing the rate of head rice rate. As the results, the characteristics of milling and rice quality was improved when the amount of top dress was reduced as 50% at the panicle initiation stage, and the yield of head rice also increased.

• Journal of Climate Change Research
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• v.5 no.1
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• pp.71-81
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• 2014

Using the Eddy Covariance technique, we analyzed seasonal variation in net ecosystem $CO_2$ exchange (NEE) and investigated the effects of environmental factors and aboveground biomass of rice on the $CO_2$ fluxes in a rice-barley double cropping paddy field of Gimje, Korea. Quality control and gap-filling were conducted before this investigation of the effects. The results have been showed that NEE, gross primary production (GPP), and ecosystem respiration (Re) during the rice growing period were -215.6, 763.9, and $548.3g\;C\;m^{-2}$, respectively. Relation between NEE and net radiation (Rn) could be described by a quadratic equation, and about 65 % of variation in NEE was explained by changes in Rn. On the other hand, an exponential function relating Re to soil temperature accounted for approximately 43 % of variation in Re under the flooded condition of paddy field. Aboveground biomass showed significant linear relationships with NEE ($r^2=0.93$), GPP ($r^2=0.96$), and Re ($r^2=0.95$), respectively.

• Korean Journal of Medicinal Crop Science
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• v.2 no.3
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• pp.181-186
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• 1994

Vegetative node and rhizome of Ligusticum chuanxiong Hort. were planted in spring and autumn and harvested after one and two years to determine the appropriate harvesting time which produced a high yield. Plant height, leaf number and branch number per plant were increased in order of rhizome planted in spring and harvested after two year(RST), rhizome planted in autumn and harvested after one year(RAO), vegetative node planted in autumn and harvested after one year(VNAO), and vegetative node planted in spring and harvested after one year(VNSO). Leaf area index and dry leaf weight in VNSO were highest on August 16, but dry weights of stem and rhizome was increased until harvesting time. The appropriate harvesting time was October 17, in RST, November 9 in RAO and VNAO, and November 13 in VNSO. Yield in autumn planting was more increased than that in spring planting and also that in RST was 443kg per 10a and increased by 2.8 times compared to RAO. However the yield in the rhizome planting was more increased by 17 percent than the vegetative node planting, the latter planting was inexpensive and economic for purchasing seed materials.

• The Korean Journal of Pesticide Science
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• v.21 no.1
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• pp.97-105
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• 2017

This study was carried out to determine residual characteristics and to evaluate safety of bifenthrin, carbendazim and metconazole in minor crop, Angelica gigas Nakai. The test pesticides were sprayed onto the crop according to the combinations of spray days before harvest and frequency and then sampling was performed at the harvest day. Non-systemic pesticide bifenthrin was not detected in all samples, whereas systemic pesticides, carbendazim and metconazole, were detected from the crop in the range of from 0.14 to 0.49 and from 0.19 to 0.26, respectively. These results indicated that residual characteristics of the test pesticides in Angelica gigas Nakai were affected by their systemic properties. Also, residual concentration of carbendazim and metconazole in the crop was increased as more spraying frequency and spraying more closer to harvest day. And residual concentration of carbendazim in the crop on the last spraying day was 2.1 times higher than that of metconazole because nominal spraying dose of carbendazim was higher than that of metconazole by 1.9 times. The residue levels of the test pesticides in the crop were evaluated to be safe, considering their %ADIs were less than 0.9%.