• Korean Journal of Soil Science and Fertilizer
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• v.21 no.2
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• pp.161-167
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• 1988

Studies were carried out to examine the effects of simulated acid rain on the various crops of rice, peper, tomato, pumpkin, egg plant, potato, soybean, radish, cucumber, common pea, sweet potato, corn, lettuce, chinse cabbage, spinach, under the condition of the rains of pH 3.0. The rain was adjusted to pH 4.0, 3.0, 2.0 with sulfuric acid, and soybeans were exposed with the various pH levels, eighteen times every other days. The symptoms of damage, ratios of destroyed leaf and sulphur content by leaves were investigated. The results obtained were as follows. 1. The exposure to the rain resulted in the reddish brown or white pigment spots in the leaves surface and the colour was developed red and darker along the edge of spots. 2. Most crops were affected with acid rain of pH 3.0 at which the amount of chlorophyl was decreased. 3. The spinach, chinese cabbage, lettuce were sensitive to the acid rain, however, the peper, tomato pumpkin were resistance to it. 4. The content of chlorophyl was decreased with increasing leave injury. 5. The sulphur content in leave was increased with increasing acidity of the rain, however the yield was decreased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.1
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• pp.56-60
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• 1997

In order to investigate the relationships between the responses of four crops (rice, soybeans, potatoes, and red pepper) to acid rain, the simulated acid rain(SAR) of pH 1.8, 2.3, and 2.8 and normal rain of pH 6.0 were applied from 30 days after emergence to harvest at the two-week interval for rice, soybeans and red pepper and at a week interval for potatoes. SAR of pH 1.8 and 2.3 caused brown spots in the leaves of rice, soybeans, and red pepper and the damages were severer as the pH of SAR lowered, while no visual damages were observed in potatoes. The SARs did not affect chlorophyll content of rice and potatoes, while chlorophyll content of soybeans and red pepper decreased as the pH of SAR lowered. Photosynthetic activity was not significantly different among the pHs of SAR in rice, while decreased as pHs of SAR lowered from pH 2.8 to 1.8 in soybeans, potatoes, and red pepper. Yield of rice, soybeans, and potatoes was not affected by the pHs of SAR, but in red pepper the length, diameter, and weight of a fruit, the number of fruits per plant, and total matured fruit yield decreased as the pHs of SAR lowered. In rice and potatoes visual damages caused by SAR did not correlated with other observed traits. However, visual damages were negatively correlated with chlorophyll content and photosynthetic activity of soybeans and photosynthetic activity and yield of red pepper.

• Journal of Aquaculture
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• v.9 no.3
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• pp.255-264
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• 1996

A 15-week growth trial was conducted to evaluate the economical feed formulations for Korean rockfish (Sebastes sehlegeli). Three replicate groups of fish averaging 33 g were fed one of 8 isoproteic ($49\%$) and isolipidic ($8\%$) diets containing various practical ingredients such as fish meal, meat meal, feather meal, blood meal, soybean meal, corn gluten meal, and wheat flour with or without supplemental essential amino acids. A control diet with white fish meal and brown fish meal as the only protein sources was included. Practical ingredients were substituted from $40\%$ up to $65\%$ for portions of the fish meals in the control diet. Essential amino acids (EAA) were added to the diets for balancing EAA composition of each dietary protein source. In addition, these experimental diets were compared with raw fish-based moist pellet containing $50\%$ frozen horse mackerel and $50\%$ commercial binder meal. Results indicated that animal and plant protein sources could substitute for fish meal up to $55\%$ in diet without any adverse effects on growth and chemical composition of fish. Fish growth, body composition, nutrient utilization, and cost of fish production are discussed in relation to nutritional values of the dietary protein sources.

• Korean Journal of Weed Science
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• v.30 no.1
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• pp.34-42
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• 2010

Competitive ability, allelopathy, made the common ragweed (Ambrosia artemisiifolia var. elatior ) one of the most dangerous weeds in Korea. The aim of this research was to evaluate the role of common ragweed as test species under laboratory bioassay and glasshouse conditions. Inhibition effect of the leaf extract was higher than that of stem and root parts extracts on germination and seedling growth of weeds. The 5% concentration of leaf extract of common ragweed inhibited the germination rate of Echinochloa crus-galli, Digitaria sanguinalis and Cyperus microiria by 68.3, 74.6 and 87.3%, respectively, as compared to the control. Generally, increasing incorporation concentration inhibited seedling growth of weeds. Incorporation of 5% common ragweed residue significantly reduced the plant length of E. crus-galli, D. sanguinalis and C. microiria by 48, 63 and 68%, respectively, as compared to the control. Also, the values of dry weight were 72, 78 and 71%, respectively. Contrarily, the emergence rate of soybean and corn was not affected by the incorporation of 5% concentration of common ragweed residue. However, the dry weight was inhibited by 37 and 28%, respectively. These results suggest that common ragweed had the ability to control some weed species using toxic compounds like natural herbicide.

• Food Science and Preservation
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• v.15 no.6
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• pp.872-877
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• 2008

This study was carried out to provide basic information related to improvement of flavor and consumption of cheonggukjang. Red ginseng cheonggukjang (RGC) and Rubus coreanum cheonggukjang (RCC) extracts were prepared, and their physicochemical characteristics were compared with either general cheonggukjang (GC) or non-fermented boiled soybean (BS). The moisture and crude fat contents were not significantly different among samples. RGC had the highest reducing sugar content and BS had the lowest. The free sugar content of RGC was higher than that of either GC or RCC, and the major free sugars present were glucose, fructose and sucrose. Seventeen free amino acids were detected in BS and cheonggukjang, and the content of free amino acids ranged from 1,233.8 to 2,599.6 mg/100 g. The greatest content of free amino acids was found in RGC. Color L, a and b values were highest in BS and lowest in RCC. The hardness and strength of RGC and RCC were lower than for GC.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.4
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• pp.334-341
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• 1992

The effects of the various pattern of paddy-upland switching system on rice yield and the nutrient absorption characteristics were examined in the paddy field of Seokcheon silty soil for three years from 1989 to 1991. The obtained results of the two years from 1990 to 1991 are as follows : 1. Rice grain yields were high in the order of potato-cabbage>soybean>continuous paddy plot for the second and third year. Among the rice yield components the numbers of grains per panicle and the rate of ripening grain exerted the yield increase. 2. The contents and absorption amounts of nutrient in harvested straw plant increased with the incease of rice yields during the second and third year(1990~1991). The amounts of all nutrient absorption increased with the increased level of nitrogen fertilization at the third year(1991). 3. The periodical change of leaf green color was responded well with the content of ammonia concentration of soil solution.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.1
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• pp.59-65
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• 2014

Generally, nitrogen (N) fertilization higher than the recommended dose is applied during vegetable cultivation for increasing in productivity. However, excessive N application rate beyond plant requirement could cause adverse environmental impact such as nitrate leaching and nitrous oxide emission. In this experiment, the impacts of N fertilization was studied on nitrous oxide ($N_2O$) emission to standardize the optimum fertilization level for minimizing of $N_2O$ emission as well as most of the crop productivity. Herein, we assessed the $N_2O$ emission in the flat upland soil which was cultivated with different N application rates on red pepper for 3 years (2010~2012). $N_2O$ emission was measured in chemical N fertilizer amounts 0 (N 0), 95 (N 0.5), 190 (N 1.0), $380(N_2.0)kgha^{-1}$ by using the abnormal shape chamber closed repeating three times. In average for 3 years, the total $N_2O$ emissions of each treatment in field of soybean were 2.110 (N 0), 3.165 (N 0.5), 5.039 (N 1.0), and $7.228(N_2.0)kgN_2Oha^{-1}yr^{-1}$, respectively. And then the primary regression between nitrogen fertilizer amount and the total $N_2O$ emission was showed as y = 0.0138x + 2.0942 ($r^2=0.9885$), and an average of the emission factor was $EF_1$ 0.0148(0.0118~0.0191) $N_2O-NkgN^{-1}kg^{-1}$ from 2010 to 2012. The result was a little higher than the emission default of the IPCC 1996 Guideline ($EF_1$ 0.0125) when the results are converted into $N_2O$ emission factor.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.2
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• pp.3-9
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• 1964

Root tips of wheat, soybean, cotton and barley were treated with cold temperature (12 or 24 hrs in $0^{\circ}C$ or 2$^{\circ}C$), 8-Hyd.exyquinolin (2 or 10 hrs in 0.03 or 0.1%) and colcllicine (2 or 10 hrs in 0.2 or 1, 0%), and the frequency of metaphase were observed. The results were summarized as follow; 1. Chilling the seminal roots before or after sooting from the seed significantly increased tile number of mitotic cells and the rate of metaphase cells to mitotic cells. The optimal duration of chilling seemed to be differ depending on the kinds of plant and 24 hours to be too long except wheat so far examined here. 9. 8-Hydroxyquinolin treatment, about 2 hours in 0.03%, increased the rate of metaphase cells. The higher concentration and the longer treatment of this chemical caused the lower frequency of mitotic cells generally. 3. Colchicine treatment, 2 to 10 hrs in 0.2 to 1.0%, increased the frequency of mitotic cells and the rate of metaphase cells. Colchicine treatment was same or superior than any other treatments on the increase of metaphase cells. 4. All the treatments examined here caused chromosome contraction with most serious in colchicine following by 8-Hydroxyquinolin and chilling. 5. The feasibility of general application of chilling under the check of proper temperature and proper duration depending on the kinds of crops were discussed.

• Journal of Applied Biological Chemistry
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• v.58 no.4
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• pp.325-332
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• 2015

Rapeseed (Brassica napus) is now the second largest oilseed crop after soybean. Cold temperature tolerance is an important agronomic trait in winter rapeseed that determines the plant's ability to control below freezing temperatures. To improve cold tolerance of rapeseed plants, an expression vector containing an Barley Ice recrystallization inhibition protein (HvIRIP) cDNA driven by a cauliflower mosaic virus 35S promoter was transferred into rapeseed plants. Transgenic expression of HvIRIP was proved by southern- and northern-blot analyses. The level of freezing tolerance of transgenic $T_3$ plants was found to be significantly greater than that of wild-type rapeseed plants by freezing assay. Proline accumulation during cold stress was also highly induced in the transgenic rapeseed plants. The transgenic plants exhibited considerable tolerance against oxidative damage induced by cold stress. Our results indicated that heterologous HvIRIP expression in transgenic rapeseed plants may induce several oxidative-stress responsive genes to protect from cold stress.

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.414-420
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• 2008

To investigate the actual condition of orchard and pest management of persimmon orchards, a questionnaire was ask to the farmers in major cultivated areas of persimmon and dried persimmon, Sangju, Gyeongbuk in 2007 and 2008. 91.1% of persimmon farmers was over fifties in age and 94.7% of persimmon farmers was cultivated 'Sangjudungshi'. The greatest limiting factor for persimmon production was thought to be disease by the 58.4% of persimmon farmers and the most serious disease was anthracnose by Colletotrichum gloeosporioides. 60.2% of them was answered that the most serious insect pest was scale insects. Obtaining of knowledge or information on pest management depended own experience (37.2%) and 48.7% of answered farmers was decision-marking of pesticides depending on agrochemical market. 54% of persimmon farmers was applied pesticides $3{\sim}5$ times per year. Just 17.7% of them recorded the diary of pesticide application. The greatest problem for management of pest in persimmon orchard was lack of knowledge of pest (60.2%) and farmers considered increasing cost for pest management as the greatest problem with 52.2% in proportion. 66.4% of farmers was mixed cultivation with soybean (37.7%) and hot pepper (26.1%) in persimmon orchard. 44.2% among answered farmers mixed cultivation of persimmon with production of dried persimmon and 54.5% of farmers considered lack of labor as the greatest problem in production of dried persimmon.