• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.878-886
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• 2011

The soybean is one of the oldest cultivated crops in the world. Microwave remote sensing is an important tool because it can penetrate into cloud independent of weather and it can acquire day or night time data. Especially a ground-based polarimetric scatterometer has advantages of monitoring crop conditions continuously with full polarization and different frequencies. In this study, soybean growth parameters and soil moisture were estimated using polarimetric discrimination ratio (PDR) by radar scatterometer. A ground-based polarimetric scatterometer operating at multiple frequencies was used to continuously monitor the soybean growth condition and soil moisture change. It was set up to obtain data automatically every 10 minutes. The temporal trend of the PDR for all bands agreed with the soybean growth data such as fresh weight, Leaf Area Index, Vegetation Water Content, plant height; i.e., increased until about DOY 271 and decreased afterward. Soil moisture lowly related with PDR in all bands during whole growth stage. In contrast, PDR is relative correlated with soil moisture during below LAI 2. We also analyzed the relationship between the PDR of each band and growth data. It was found that L-band PDR is the most correlated with fresh weight (r=0.96), LAI (r=0.91), vegetation water content (r=0.94) and soil moisture (r=0.86). In addition, the relationship between C-, X-band PDR and growth data were moderately correlated ($r{\geq}0.83$) with the exception of the soil moisture. Based on the analysis of the relation between the PDR at L, C, X-band and soybean growth parameters, we predicted the growth parameters and soil moisture using L-band PDR. Overall good agreement has been observed between retrieved growth data and observed growth data. Results from this study show that PDR appear effective to estimate soybean growth parameters and soil moisture.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.4
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• pp.386-408
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• 1988

A study was conducted to develop a model for estimating evapotranspiration and yield of Chinese cabbages from meteorological factors from 1981 to 1986 in Suweon, Korea. Lysimeters with water table maintained at 50cm depth were used to measure the potential evapotranspiration and the maximum evapotranspiration in situ. The actual evapotranspiration and the yield were measured in the field plots irrigated with different soil moisture regimes of -0.2, -0.5, and -1.0 bars, respectively. The soil water content throughout the profile was monitored by a neutron moisture depth gauge and the soil water potentials were measured using gypsum block and tensiometer. The fresh weight of Chinese cabbages at harvest was measured as yield. The data collected in situ were analyzed to obtain parameters related to modeling. The results were summarized as followings: 1. The 5-year mean of potential evapotranspiration (PET) gradually increased from 2.38 mm/day in early April to 3.98 mm/day in mid-June, and thereafter, decreased to 1.06 mm/day in mid-November. The estimated PET by Penman, Radiation or Blanney-Criddle methods were overestimated in comparison with the measured PET, while those by Pan-evaporation method were underestimated. The correlation between the estimated and the measured PET, however, showed high significance except for July and August by Blanney-Criddle method, which implied that the coefficients should be adjusted to the Korean conditions. 2. The meteorological factors which showed hgih correlation with the measured PET were temperature, vapour pressure deficit, sunshine hours, solar radiation and pan-evaporation. Several multiple regression equations using meteorological factors were formulated to estimate PET. The equation with pan-evaporation (Eo) was the simplest but highly accurate. PET = 0.712 + 0.705Eo 3. The crop coefficient of Chinese cabbages (Kc), the ratio of the maximum evapotranspiration (ETm) to PET, ranged from 0.5 to 0.7 at early growth stage and from 0.9 to 1.2 at mid and late growth stages. The regression equation with respect to the growth progress degree (G), ranging from 0.0 at transplanting day to 1.0 at the harvesting day, were: $$Kc=0.598+0.959G-0.501G^2$$ for spring cabbages $$Kc=0.402+1.887G-1.432G^2$$ for autumn cabbages 4. The soil factor (Kf), the ratio of the actual evapotranspiration to the maximum evapotranspiration, showed 1.0 when the available soil water fraction (f) was higher than a threshold value (fp) and decreased linearly with decreasing f below fp. The relationships were: Kf=1.0 for $$f{\geq}fp$$ Kf=a+bf for f$$I{\leq}Esm$$ Es = Esm for I > Esm 6. The model for estimating actual evapotranspiration (ETa) was based on the water balance neglecting capillary rise as: ETa=PET. Kc. Kf+Es 7. The model for estimating relative yield (Y/Ym) was selected among the regression equations with the measured ETa as: Y/Ym=a+bln(ETa) The coefficients and b were 0.07 and 0.73 for spring Chinese cabbages and 0.37 and 0.66 for autumn Chinese cabbages, respectively. 8. The estimated ETa and Y/Ym were compared with the measured values to verify the model established above. The estimated ETa showed disparities within 0.29mm/day for spring Chinese cabbages and 0.19mm/day for autumn Chinese cabbages. The average deviation of the estimated relative yield were 0.14 and 0.09, respectively. 9. The deviations between the estimated values by the model and the actual values obtained from three cropping field experiments after the completion of the model calibration were within reasonable confidence range. Therefore, this model was validated to be used in practical purpose.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.1
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• pp.13-21
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• 1985

This experiment was carried out to study the effect of the autumnal cutting times on the regrowth, the accumulated carbohydrate and dry matter yield of Italian ryegrass The results were summarized as follows: 1. In dry matter yield, the plot of earlier cutting was shown the highest yield (p<0.05), and that of the last-cutting was shown lower yield of dry matter than that the none-cutting plot. 2. TSC (Total Water Soluble Carbohydrate) content slightly decreased after the first cutting and gradually increased according to the regrowth, and then decreased again to the second cutting time. And also the TSC content levels of stubble, stem and leaf at one week before falling to sub-zero temperature were all the highest in the eariler cutting plot (p<0.01), and there was significant correlation between the TSC content level and the second harvested dry matter yield (p<0.05). 3. CGR (Crop Growth Rate) was decreased below $8^{\circ}C$. RLGR (Relative Leaf area Growth Rate) and NAR (Net Assimilation Rate) were both high during 30 days after regrowth, and low after regrowth in all plots. LAI (Leaf Area Index) rapidly increased during 50 days after cutting, and then slowly increased in all the plots, and maximum LAI was 3.4-5.8. Also dry matter yield increased in the plots having a high LAI to 70 days after cutting. 4. It was recognized that there were significant correlation between TSC, LAI, CGR, NAR, LWR (Leaf Weight Ratio) and the second harvested dry matter yield during the low temperature periods, and the degree of contribution to dry matter yield was in order of LWR>LAI>TSC>NAR>CGR.

• Journal of Korean Society of Forest Science
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• v.49 no.1
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• pp.11-31
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• 1980

The morphological, anatomical and physiological traits were eximined for Populus alba ${\times}$ glandulosa which is an important planting species in Korea. The results obtained are as follows: 1. External characters in the leaf shape and chaff shape in the catkin were inherited as incomplete dominance but nectar gland was inherited as dominance. 2. Among the 15 selected clones, 9 clones were male, 2 clones female and 2 clones monoecious. 3. There were well-developed cork layers and bast fiber bundles in the bark. 4. Primordial leaves composed of 3 layers of cells and those undifferentiated into palisade and spongy parenchymas differed in its origin. 5. Leaf scare consisted of two kinds of tissues; one is connected to vascular bundle and the other not to vascular bundle. Tissues which had been connected to vascular bundle were isolated with only 2 or 3 layers of cork cells from the outside. 6. There was complicated arrangement in the vascular bundle of petioles. 7. Growth of the hybrid was sensitively influenced by external temperature, day-length and amount of light. In particular, it was apparent in height growth. 8. Flatness, loam soils and a $60{\times}60cm$ spacing might be best factors for the growth of P. alba ${\times}$ glandulosa. 9. The rooting of 15 clones was dependant upon external factors. 10. The growth of P. alba ${\times}$ glandulosa was best at around 80% of soil moisture content on the basis of plot water capacity. 11. Temperature difference between inside and outside stems below 100cm during the winter was the greatest at the south among seasons and among directions. 12. The sap movement was markedly influenced by air temperature, relative humidity in forest stand and moisture content in stem. 13. Total sugars in the cortex changed with season but did not differ in the dircetion of the stem. 14. Isoperoxidase variations in the leaf were different among 15 clones. Thus, it may be useful as a criterium for clonal identification. 15. The rate of soil moisture content decreased at a rapid slope was faster than that at a slow slope. Poor growth of P. alba ${\times}$ glandulosa at the slope was probably due to depletion of soil moisture.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.2
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• pp.105-110
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• 2013

This study was carried out to investigate the effect of nitrogen (N) fertilization on the forage growth, production and quality of native reed (Phragmites communis) grasses. Field experiments were conducted in Cheonan and in Ansan, 2012. Treatments were control (no N fertilization), 50 kg/ha and 100 kg/ha in Cheonan plots (fertilization on April $30^{th}$, and harvest on June $21^{st}$). Treatments in Ansan plots were control (no N fertilization) and 60 kg/ha (fertilization on May first, and harvest on August first). Forage growth and leaf colors were improved in N fertilized plots. However, the drymatter (DM) percentage was slightly decreased with N fertilization. Forage yields, in terms of DM, crude protein (CP) and digestible DM (DDM), were significantly increased with N fertilization in both sites. In Cheonan, DM, CP and DDM yields per ha were 4,026 kg, 235 kg and 1,850 kg, respectively, in the control plot, and were 4,658 kg, 306 kg and 2,388 kg, respectively, in the N 50 kg plot, and 5,622 kg, 446 kg and 3,143 kg, respectively, in the N 100 kg plot. In Ansan, DM, CP and DDM yields per ha were 2,802 kg, 177 kg and 1,288 kg, respectively, in the control plot, and were 3,876 kg, 294 kg and 1,853 kg, respectively, in the N 60 kg plot. Forage quality in terms of CP content, in vitro DM digestibility (IVDMD) and relative feed value (RFV) were also increased with N fertilization in both sites. In Cheonan, the CP content, IVDMD and RFV were 5.85%, 45.96% and 64.5 (grade 5), respectively, in the control plot, 6.58%, 51.27% and 72.3 (grade 5), respectively, in the N 50 kg plot, and 7.94%, 55.91% and 72.7 (grade 5), respectively, in the N 100 kg plot. In Ansan, the CP content, IVDMD and RFV were 6.30%, 45.98% and 70.2 (grade 5), respectively, in the control plot, and 7.59%, 47.80% and 78.3 (grade 4), respectively, in the N 60 kg plot. In conclusion, N fertilization of 60~100 kg/ha was desirable for greater forage production, with a higher quality of native Phragmites communis achievable. This should only be applied if the fertilization area is not located at a riverside/streamside or in riparian land where there is a high risk of water pollution by fertilization.

• Journal of Nutrition and Health
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• v.54 no.2
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• pp.211-223
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• 2021

Purpose: A total of 39 seafood menus were prepared according to the Korean standard recipe, and analyzed for vitamin B₉ (folate) and B₁₂ (cobalamins) contents, using validated applied analytical methods. The menus included Guk/Tang/Jjigae (boiled or stewed dishes, n = 10), Bokkeum (stir-fried dishes, n = 10), Jjim/Jorim (braised or steamed dishes, n = 7), Gui (baked or grilled dishes, n = 7), Twigim (deep-fried dishes, n = 2) and Muchim (dried or blanched-seasoned dishes, n = 3). Methods: The contents of vitamin B₉ and B₁₂ in all food samples were determined by the trienzyme extraction-Lactobacillus casei and immunoaffinity-high-performance liquid chromatography/photodiode array detection methods. Analytical quality control was performed in order to assure reliability of the analysis. Results: Accuracy (97.4-100.6% recoveries) and precision (< 6% relative standard deviations for repeatability and reproducibility) of vitamin B₉ and B₁₂ analyses were determined to be excellent. The vitamin B₉ and B₁₂ contents of the 39 seafood menus evaluated, varied in the range of 1.83-523.08 ㎍/100 g and 0.11-38.30 ㎍/100 g, respectively, depending on the ingredients and cooking methods. The vitamin B₉ content was highest in Jomi-gim (523.08 ㎍/100 g), followed by Geonsaeu-bokkeum (128.34 ㎍/100 g) and Janmyeolchi-bokkeum (121.53 ㎍/100 g). Vitamin B₁₂ was detected in all seafood menus, with highest level obtained in Kkomack-jjim (41.58 ㎍/100 g). The seaweed dish was found to have high levels of both vitamin B₉ and B₁₂. All assays were performed under strict quality control. Conclusion: Guk and Tang menus, which contain a large amount of water, were relatively lower in the vitamin B₉ and B₁₂ contents than the other menus. Bokkeum menus containing various vegetables were high in the vitamin B₉ content, but the vitamin B₁₂ content was dependent on the type of seafood used in the menu.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.298-302
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• 2016

This study evaluated the effect 3 types of conditioning (Untreated, Impeller, Roller) and the number of times for tedding (rake-teder) performed in one day on the drying rate of tall fescure hay. The experiment was performed at The forage site of Cheonan-si seongwhan-eup National Institute of Animal Sciencee. It took 3 days to make tall fescue hay. The Impeller and Roller conditioning types shortened the haymaking period by 1 day compared to untreated hay. Impeller and roller samples had less than 20% of water content by the $23^{rd}-day$ at 13 o'clock. Tedding frequency failed to affect haymaking. There was no correlation between the three types of conditioning or tedding frequency and acid digestible fiber (ADF), neutral detergent fiber (NDF), total digestible nutrients (TDF), crude protein (CP), or relative feed value (RFV) in tall fescue hay. CP was 12.5~12.9% for the three types of conditioner with 1 or 2 times of tedding a day, Threrfore, conditioner types and gedding frequency had no significant effect on CP.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.3
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• pp.359-366
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• 1993

Molds are eucaryotic, multicellular, multinucleate, filamentous organisms that reproduce by forming asexual and sexual spores. The spores are readily spread through the air and because they are very light-weight and tend to behave like dust particles, they are easily disseminated on air currents. Molds therefore are ubiquitous organisms that are found everywhere, throughout the environment. The natural habitat of most molds is the soil where they grow on and break down decaying vegetable matter. Thus, where there is decaying organic matter in an area, there are often high numbers of mold spores in the atmosphere of the environment. Molds are common contaminants of plant materials, including grains and seeds, and therefore readily contaminate human foods and animal feeds. Molds can tolerate relatively harsh environments and adapt to more severe stresses than most microorganisms. They require less available moisture for growth than bacteria and yeasts and can grow on substrates containing concentrations of sugar or salt that bacteria can not tolerate. Most molds are highly aerobic, requiring oxygen for growth. Molds grow over a wide temperature range, but few can grow at extremely high temperatures. Molds have simple nutritional requirements, requiring primarily a source of carbon and simple organic nitrogen. Because of this, molds can grow on many foods and feed materials and cause spoilage and deterioration. Some molds ran produce toxic substances known as mycotoxins, which are toxic to humans and animals. Mold growth in foods can be controlled by manipulating factors such as atmosphere, moisture content, water activity, relative humidity and temperature. The presence of other microorganisms tends to restrict mold growth, especially if conditions are favorable for growth of bacteria or yeasts. Certain chemicals in the substrate may also inhibit mold growth. These may be naturally occurring or added for the purpose of preservation. Only a relatively few of the approximately 100,000 different species of fungi are involved in the deterioration of food and agricultural commodities and production of mycotoxins. Deteriorative and toxic mold species are found primarily in the genera Aspergillus, Penicillium, Fusarium, Alternaria, Trichothecium, Trichoderma, Rhizopus, Mucor and Cladosporium. While many molds can be observed as surface growth on foods, they also often occur as internal contaminants of nuts, seeds and grains. Mold deterioration of foods and agricultural commodities is a serious problem world-wide. However, molds also pose hazards to human and animal health in the form of mycotoxins, as infectious agents and as respiratory irritants and allergens. Thus, molds are involved in a number of human and animal diseases with serious implication for health.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.62-67
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• 1991

The characteristics of Tongjinbyeo(Japonica) and Samgangbyeo($J{\times}Indica$) rice starches including physicochemical properties, differential scanning calorimetry and enzymatic digestion of lintnerized starches were investigated. Degree of hydrolysis of Tongjinbyeo starch with 2.2N HCI for 48 hr was higher than that of Samgangbyeo starch. Apparent first order reaction of starches was slow reaction for first period, and fast reaction second period on the datum point of acid treatment 24 hr. Absorbance at ${\lambda}_{max}$ and 680 nm, and ${\lambda}_{max}$ of iodine stained starch and amylose content decreased upon acid treatment. But water binding capacity, swelling power and solubility considerably increased as hydrolysis progressed. Relative crystallinity of two starches increased with acid treatment, and that of Tongjinbyeo starch was higher than that of Samgangbyeo starch. Differential scanning colorimetry(DSC) data continuously decreased for lintnerization periods, and those of Tongjinbyeo starch have higher than those of Samgangbyeo starch. The onset temperature of starch by DSC continuously decreased by treatment, but conclusion temperature increased until 24 hr and then decreased. The enthalpy for gelatinization decreased for both starches. Degree of hydrolysis of lintnerized Tongjinbyeo starch with glucoamylase was slightly higher than that of Samgangbyeo starch.

• Environmental Mutagens and Carcinogens
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• v.15 no.2
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• pp.115-121
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• 1995

Bacterial mutagenicity of shellfish or canned products of red-muscle fish affected by hot-airdry processings and/or during storages was investigated by Ames preincubation method. Mussel (Mytilus edulis) and surf clam (Tapes japonica) dried under either 40$\circ$C, 50$\circ$C or 60$\circ$C until remained about 25 % water content was stored at 4$\circ$C or 25$\circ$C for 6 months. Commercially available canned product of pacific saury (Cololabis saira) and mackerel saury (Scotnberjaponicus), whose producer or date of manufacture was identical each other, was stored at 25$\circ$C for 6 months. Mutagenic substances from sample (25 g dry weight) were extracted and purified for mutagenicity assay against S. typhitnurium TA98 by the simultaneous distillation extraction (SDE) method (Lee et al. 1955). Mutagenicity of sample was expressed number of revertant per 25 g dry sample. Number of revertant from unheated mussel sample was appeared to be 135, relative to 22 from unheated surf clam sample. Mutagenicity of both shellfish was strongly affected by heat treatment, but a lesser extent by storage conditions, even at 25$\circ$C for 6 months. Revertants of the mussel sample dried at 40$\circ$C, 50$\circ$C, or 60$\circ$C was found to be 227, 779, and 883, respectively. Similar, but lower, mutagenicity was observed from the sample of surf clam dried at 40$\circ$C, 50$\circ$C, or 60$\circ$C than mussel. Mutagenicity of canned pacific saury and mackerel samples was not influenced by storage conditions. Number of revertant from pacific saury was 175 which was relatively higher than 5 from mackerel. Mutagenicity of fresh pacific saury and mackerel samples was significantly higher than that of their counterparts from canned products. These results indicate that mutagenicity of the shellfish was affected by heat treatment (40$\circ$C, 50$\circ$C, or 60$\circ$C) used for drying process, but not much by storage for 6 months at 4$\circ$C or 25$\circ$C and the mutagenicity of canned products of red-muscle fish was not influenced by storage, even at 25$\circ$C for 6 months.