• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.15
• /
• pp.69-75
• /
• 1974

This experiment was conducted to investigate the influence of different amount of nitrogen and deficiency of soil moisture on yield components of soybean. Soybean were seeded on 1/2000a wagner pot. Deficiency of soil moisture was treated at each growth atage of soybean. 1.In case of deficiencyt of soil moisture at the flowering time in the plot of non-nitrogen(NO D3), the growth duration of soybean was shortened about three to four days. 2. The leaf area was greatly affected by the influence of both treatments till 49days after germinating. 3.The increase of stem height, stem doameter,number of branches and lengeh of the branches came to an end about 70 days after seeding. These growing condition of tje soybean were lowest the plot of No D$_1$,in which the frowth of the soybeans were poor at the early stage. 4.The number of pods was not increased by the increase of fertilizing nitrogenous fertilizer. The number of pods was much decreased by the influence of soil mousture deiciency, and under this condition, the proportion of main stem pods and two or three grain pods was high. 5.The 3rd and 4h nodes and the 10th to 12th nodes from bottom had more pods than the other nodes had, but of the plants had grown well, they had more pods on the 3rd and 4th nodes, but if the plants had grown poorly, they had more pods on the 10th to 12th nodes. 6.The content of protein in the soybean was low at the plit of N。D$_4$which had not heavy weight of 100 grains, and the content of oil in the soybean was low in the plot in which each plant had a small number of grains.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.29 no.3
• /
• pp.267-274
• /
• 1984

This experiment was carried out to investigate the stomatal aperture of wheat variety 'Chokwang' grown in the two different nitrogen level. Stomatal aperture was measured at the maximal tillering, shooting, booting, flowering and grain filling stages. Stomatal aperture in leaf blades gradually increased in accordance with the successive leaf growth. The maximal opening of stomata was observed at flowering stage and around noon in a day, but stomata closed around six o'clock in the afternoon. Stomata opened wider in the high nitrogen application than in the low nitrogen and their effects were the highest at the booting and flowering stage. Diurnal course at stomatal aperture of upper leaves was wider than that of lower leaves regardless of growth stages. Positive correlation (r=0.66$^{**}$) appeared between nitrogen content in leaf blades and stomatal aperture. The leaves of low position and the developing leaves showed smaller stomatal aperture than the full expanded top leaves irrespective of leaf stages. Water content of leaf, root weight and root activity were increased by the nitrogen application and thus considered as factors increase the stomatal aperture.ication and thus considered as factors increase the stomatal aperture.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.34 no.3
• /
• pp.246-251
• /
• 1989

A medicinal legume crop, Cassia tora L., was grown with four different seeding dates in 1986 field condition to find the flowering and pod setting characteristics. Initial flowering date and flowering duration were almost same between plants sown from April 20 to May 30, but those of plants seeded at June 20 were significantly delayed and shortened. Last flowering date, however, was not different between plants sown from April 20 to June 20. C. tora plants showed indeterminate flowering habit, and bloomed vigorously from fourth date after initial flowering. Numbers of flowers, ovules and pods per plant were decreased along with delaying seeding date, and ovule to flower ratio and pod to flower ratio were greatly decreased in June 20 seeding plot. Flowers bloomed on second week from initial flowering showed the highest number of ovules and pods, and flowers bloomed after early September did not develop to matured pods. Maximum values of pod length, number of seeds per pod and 1000-grain weight were obtained from flowers bloomed on second week from initial flowering of plants sown from April 20 to May 30, and first week in June 20 seeding plot.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.32 no.2
• /
• pp.163-172
• /
• 1987

Results obtained from this study conducted to find the effect of wind-break net on reducing cold wind damage in the eastern coastal cold wind damaged area are summarized as follows. The rice critical safe heading date was up to Aug. 10 in the eastern coastal area, which the frequency of gale Aug. 10 to Sep. 10 is high. The frequencies of westries and cold wind from sea were 25%, respectively, in this area. The effects of wind-break net on reducing wind verocity were 26.9, 34,6% with raising air temperature of 0.4-0.7$^{\circ}C$ and water temperature of 0.3-0.5$^{\circ}C$. The effect of wind-break net was up to 10 time's distance of wind-break net's height from wind-break net. The installation of wind-break inhanced to rice growth, so showed the heading date earlier by 2-5days and increased culm length, no.of panicles per hill and no. of spiklets per panicle. The yield decrease in this area was due to sterilization, poor ripening and light 1,000 grain weight. The yields showed 20-28% increase by installation of wind-break net. The effect of wind-break net was most in the installation plot with wind-break net against cold wind from sea and westries installed in the panicle formation stage.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.55 no.1
• /
• pp.70-75
• /
• 2010

In Korea, standard N application level was amended from 110 to 90kg per ha for high quality rice production in 2005. So far, N application method, however, has not been considered for yield and quality based on changed standard N application level. Therefore, this experiment was conducted to find out more efficient N application method for improving rice quality or labor saving under the amended standard N application level with several varieties at three site (Suwon, Iksan, and Milyang) for two years from 2005 to 2006. Top dressing of N at 15 days before heading compared to the standard (25 days before heading) showed improved rice qualities such as 1000 grain weight and head rice ratio without changing rice yield and protein content of brown rice. In addition, there were no significant differences in yield and quality between different N split application of 70-0-30% and 50-30-20%, indicating that the former would be useful for labor saving without yield decrease and quality deterioration.

• Economic and Environmental Geology
• /
• v.30 no.4
• /
• pp.279-289
• /
• 1997

Dark to pale green-colored, Cr-bearing sericites from hydrothermal alteration zone of the Narim gold deposit were investigated mineralogically and geochemically. The alteration zone is composed mineralogically of quartz, carbonate minerals and green sericite with minor amounts of chlorite, barite and sulfide minerals (pyrite, sphalerite, galena). The zone is enriched in As (967 to 1520 ppm), Cu (31 to 289 ppm), Ni (1027 to 1205 ppm), Pb (0.20 to 1.24 wt.%) and Zn (1.03 to 1.07 wt. %) compared with fresh rocks such as granitic gneiss, porphyritic biotite granite and basic dyke. The Cr, probably the chromophore element, is highly enriched in the alteration zone (1140 to 1500 ppm), host granitic gneiss (1200 ppm) and porphyritic biotite granite (1200 ppm). Occurrence and grain size of sericite are diverse, but most of the Cr-bearing sericites (150 to $200{\mu}m$ long and 20 to $30{\mu}m$ wide) occur along the boundaries between ore veins and host rocks (especially basic dyke and granitic gneiss). X-ray diffraction data of the sericite show its monoclinic form with unit-cell parameters of $a=5.202{\AA}$, $b=8.994{\AA}$, $c=20.103{\AA}$, ${\beta}=95.746^{\circ}$ and $V=935.83{\AA}^3$, which are similar with the normal 2M1-type muscovite. Representative chemical formula of the sericite is ($K_{1.54}Ca_{0.03}Na_{0.01}$)($Al_{3.42}Mg_{0.38}Cr_{0.14}Fe_{0.06}V_{0.02}$)($Si_{6.69}Al_{1.31}$)$O_{20}(OH)_4$. The Cr content increases with decrease of the octahedral Al content, and ranges from 0.36 to 2.58 wt.%. DTA and TG curves of the sericite show endothermic peaks at $342^{\circ}$ to $510^{\circ}$, $716^{\circ}$ to $853^{\circ}$ and $1021^{\circ}C$, which are due to the expulsion of hydroxyl group. The total weight loss by heating is measured to be about 8.8 wt. %, especially at $730^{\circ}C$. Infrared absorption experiments of the sericite show broad absorption band due to the O-H bond stretching vibration near the $3625cm^{-1}$, coupled with the 825 and $750cm^{-1}$ doublet. The vibration bands related with the H-O-Al and Si-O-Al bonds occur at $1030cm^{-1}$ and 500 to $700cm^{-1}$, respectively. Based on paragonite content of the sericite, the formation temperature of the Narim gold deposit is calculated to be $220{\pm}10^{\circ}C$.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 1999.11a
• /
• pp.102-144
• /
• 1999

The major problems of food crop cultivation in Korea are low yield of most crops except rice. inefficient cultivation techniques for aged farmers. and low international competibility. Therefore, development of cultivation techniques of food crops should aim the yield. quality improvement, labor reduction and production cost. The primary issue for increasing the yield of soybean, barely and wheat is to reduce the yield gap between the farmer's yield and recommended ones of experiment station. More advanced cultivation techniques needs to be developed. and/or the conventional breeding methods to be reconsidered. The newly developed labor-saving mechanized technique needs to reduce labor hours , and the cost of agricultural implements and machineries. In other words the labor-saving mechanized technique should be developed based on the improvement of total farming system as well as systemic fundamental innovation of cultural methods. The efficiency of solar energy use in food production of Korea in 1997 is as low as $0.52{\%}$ so there is much room to increase yield. It is recommendable that the concept of food Production should be changed to energy Producing efficiency Per unit area basis from volume and weight of food materials. Moreover, introduction of resonable cropping system is needed to increase yield of main crops, farmer's income, solar energy use efficiency, and decrease of land service expenditure. Current cropping system emphasized on economic crops. especially in vegetables , is not desirable for resonable use of arable land. stability of agricultural management and staple food crop self-sufficiency ratio. It is desirable to increase food crops . that are energy of carbohydrate and protein rich and land dependent crops. in cropping system. And the agronomist should develop the cultural methods to replace food crops for food self-sufficiency and stable farming management instead of economic crops in current cropping system. Low-input and environmentally-sound crop cultivation techniques, especially nitrogen-reducing culture technique which is directly related to food crop quality, also needs to be developed urgently. The extended cultivation of corn in upland and barely and wheat in lowland as a feed stuffs is recommended to prevent further decrease of food self-sufficiency ratio, which is mainly caused by the high reliance on imported feed grain. It is also considered that the calculation and presentation methods of standard agricultural income needs to be improved. The current calculation method uses unit land area of 10a regardless of crop kinds , characteristics of agricultural management and cultivation scale. So, it is apt to lead misunderstanding of farm income value. Therefore. it should show an income of average farmers for certain number of years. Research and developing system for food producing is not desirable because they are conducted currently individual crop and mono-culture basis. But actual agricultural income is usually earned by cropping system including upland and lowland. For example. the barley and wheat is usually cultivated in double cropping system. The cooperation among research institutes such as university agribusiness. government and farmers is indispensible. The public information and education on importance and consumption habit of food crops is necessary in Korean society to increase food self-sufficiency through nationwide cooperation.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.33 no.4
• /
• pp.329-335
• /
• 1988

[n order to find out the effects of nitrogen fertilizer and planting density on the leaf characteristics of high yielding cultivars of rice, Dongjin (Japonica type) and Samkang (Tongil type) were .grown under two nitrogen levels (150 and 250 kg N/ha) and three planting densities (30 ${\times}$ 15 cm, 30 ${\times}$ 12 cm, 30 ${\times}$ 9 cm. Leaf blade, sheath and dry weight of individual leaf. the number of green leaves after flowering were measured. Samkang was characterized as longer and wider leaf blade and sheath than Dongjin, less sensitive to nitrogen fertilizer and planting density, and higher proportions of green leaves after flowering. These morphological characteristics of Samkang caused an increase of grain yield by 30 per cent.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.2
• /
• pp.174-182
• /
• 1993

Performance of 3 indica ${\times}$ japonica(Chilseungbyeo, Samgangbyeo, and Gayabyeo), 7 japonica(Yeongsanbyeo, Yeongdeugbyeo, Hwajinbyeo, Palgongbyeo, Seumjinbyeo, Tamjinbyeo, and Milyang 95), and 2 indica(Tebonnet and Lemont) rice varieties was tested at 1, 3, 5, and 7cm seeding depths in a growth chamber and field. In the growth chamber the number of days from seeding to seedling emergence increased as seeding depth increased, while percent germination and emergence and emergence / germination ratio decreased. However, in the field seedling emergence at 1em seeding depth delayed slightly compared to 3cm probably due to lack of soil moisture. The number of seedlings and maximum tillers at 1, 3, and 5cm seeding depths was similar, but it was higher compared to 7cm seeding depth. Yield and yield components were similar among the seeding depths when all the varieties averaged although 1,000-grain weight was slightly higher at 7cm deeding depth compared to others. At 1cm seeding depth the length of mesocotyl of all varieties was similar and ranged 0.1-0.2cm and that of coleptile ranged 0.8-1.1cm. As seeding depth increased up to 7cm Tebonnet which showed the highest percent emergence emerged by elongation of both mesocotyl and coleoptile, while the other varieties emerged largely by elongation of coleoptile.

• Korean Journal of Environmental Agriculture
• /
• v.3 no.1
• /
• pp.52-56
• /
• 1984

In order to evaluate the applicability of two kinds of antibiotic fermentation residues on rice and tomato growth, yield, yield components, and some indicators for plant growing status were checked including analysis of physico-chemical properties of these two antibiotic fermentation residues. The results obtained are as follows: 1) These two antibiotic fermentation residues contain high organic matter ($21.6{\sim}24.2%$), phosphorus ($2900{\sim}4600 ppm$) and exchangeable cations ($55.4{\sim}138.3 meq/100 g$,), showing their pH values of $7.0{\sim}8.0$ range. 2) Both have developed net positive charge rather high and stiffly that exhibits high negative ion adsorption capacities, accordingly showing higher zero point of charges($pH 7.0{\sim}8.0$) than those of common soils. 3) The effect of the two kinds of antibiotic fermentation residues on rice growth was more or less the same comparable to the effect of the other fertilizers applied, showing the maximum yield at the application rate of 40 ㎏/10a. 4) The effect of these antibiotic fermentation residues on tomato growth was also similar to effects on rice plant showing the yield increment upon fertilizer application including two antibiotic fermentation residues but no significant differences among fertilizers. 5) According to the plant growing status, plant height, dry matter, number of effective tillers and grain number per panicle of rice and plant height and fresh weight of plant of tomato showed similar trend with yield of both plants.