• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.304-311
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• 1993

To find out suitable crops and their rotation years with rice for paddy-upland rotation, continuous rice cropping and rice with 1, 2 and 3 years cropping of upland crops(soybean, maize and job's tears) were tested for four years from 1989 to 1992. Rice yield, when averaged over rotation years for each crop, was increased ranging from 7% to 12% when compared with that of continuous rice cropping. With every crop, rice yield of 2 year upland rotation was higher than that of 1 year upland rotation, but rice quality seemed to deteriorate in paddy-upland rotation. When considering yields of the upland crops, 1 year rotation was the best condition for soybean and job's tears, with 3 years rotation being the best for maize. In paddy-upland rotation, number of weed species and its occurrence rates were reduced in paddy and upland condition and the reduction rates in paddy condition were higher than those in upland condition. Physical properties of soil were improved in paddy-upland rotation and airphase seemed to increase with increasing upland period.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.6
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• pp.463-471
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• 2000

A pot experiment was carried out to find out the effects of the sludge application on corn and Chinese cabbage growth and changes in soil chemical properties with sludges collected from 4 plants at 0, 12.5, 25, 50, and $100Mg\;ha^{-1}$ levels and chemical fertilizer. With the corn experiment, the pot where sludge and chemical fertilizers were treated together, greater amount of sludge resulted in initial growth inhibition. In general, higher sludge treatment rates resulted in better growth in the end, whereas initial growth was inhibited due to high the electrical conductivity of saturated extracts(ECe) for the Chinese cabbage. However, the highest yield among sludge treatments was lower than the yield with chemical fertilizers. While the treatments resulted in chemical changes in soil showing differences of cation exchange capacity, organic matter contents, and nitrogen contents, hardly any changes were detected before and after crops were grown. Inorganic nutrients such as Na, K, Ca and Mg showed similar changes. The ECe in soil saturation extract decreased after crops were grown. The more sludge was treated, the greater was the decrease. The differences of ECe in the soil saturation extract with varying degrees of treatment were also reduced after crops were grown. Available phosphorus content increased during growth. Due to the low nitrogen content in sludge, when nitrogen becomes the determining factor for the amount of sludge treatment, phosphorus buildup resulted from continued application of sludge could be raised. Therefore, it is advisable to use phosphorus, not nitrogen content, in determining the amount of sludge treatment and chemical fertilizer as supplementary sources for nitrogen.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.6
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• pp.625-635
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• 1990

The purpose of this study was focused on investigation of biochemical properties of amylases in germinating corn(Zea mays L.) the amylase(I), (II) and (III) from germinating corn seeds were partially purified by ammonium sulfate precipitation, DEAE-Sephadex A-50 ion exchange column chromatography and Sephadex G-100 gel filtration. The last step was effective for separation of the corn amylases to a homogeneous slate. the purified amylase(I) was identified as a kind of $\alpha$-amylase from the fact that 5％ starch solution was hydrolysed into mainly maltose and maltotetrose by it, and amylase(II) and amylase(III) were enzymes producing maltotetrose as main product. The molecular weight and specific activity of the amylase(I), (II) and (III) were determined to be 54,000 and 70.47 unit/mg, 39,000 and 62.98 unit/mg, and 51,000 and 80.39 unit/mg, respectively. It showed a tendency to increase the amylases activities in presence of Ba, Ca, Co and Fe groups, but inhibits in that of Ag, Sn, Hg and Zn groups, and amylase(I), (II) and (III) remained stable at pH 5-6 and 2$0^{\circ}C$ for 40 days in containing of 1 mM CaCl$_2$. The optimum pH and optimum temperatures were pH 6, pH 5 and pH 6 and 35$^{\circ}C$, 55$^{\circ}C$ and 55$^{\circ}C$, respectively. These results suggest that the amylase(I), (II) and (III) were different amylases.

• Korean Journal of Agricultural Science
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• v.30 no.2
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• pp.123-127
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• 2003

In order to develop the crude forage maize hybrids with high dry matter and grain yield, several hybrids evaluated as superior hybrids at three regions in 2001. They were planted and surveyed again for second selection in 2002. The selected hybrids showed large difference in some major characteristics according to planting areas and dates(Suwon ; April 25, Daejeon ; May 15 and Milyang ; May 25), but insect and disease injury were similar to check. Fresh and dry weight of the H67 hybrid at Suwon and Daejeon was the highest among hybrids including check, but low in Milyang due to raining after flowering. Grain yield was higher than check in H15 at Suwon, H45 and H37 at Daejeon and H67 at Milyang.

• Current Research on Agriculture and Life Sciences
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• v.32 no.2
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• pp.105-109
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• 2014

The soybean [Glycine max (L.) Merr.], an edible legume, has a high protein content in both its hay and grain, so it is often used as a supplement for other forages that have a deficient protein concentration. Therefore, this study investigated the forage quality and yield in the case of mixed planting of soybean and corn. The forage yield and quality were assessed for three cropping patterns: soybean mono planting, corn mono planting, and mixed planting of soybean and corn. For planting, this study used a forage corn cultivar, Kwangpyeongok, and three recombinant inbreed lines, W2, W4, and W11, selected from Glycine soja (PI483463)${\times}$G. max (Hutcheson). The mixed planting of soybean and corn produced a higher forage yield than the corn mono cropping. The crude protein and crude fat content were also increased with the mixed planting of soybean and corn when compared with the corn mono cropping. Some decrease of ADF and NDF, and increase for RFV in mixed planting of soybean and corn than corn mono cropping. Therefore, the results show that mixed planting of soybean and corn is an effective cropping system to improve the forage quality.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.416-425
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• 2020

This study evaluated the productivity of early maturity silage corns during continuous monocropping and the possibility of expanding forage production. Continuous monocropping of three silage corns, such as Kwangpyeongok (medium maturity), Sinhwangok (early maturity), and Sinhwangok2 (early maturity) was planted twice, in April and July from 2018 to 2019 at Suwon. The number of days from the sowing date to the silking date was 78 for the preceding crop and 52 for the succeeding crop. The number of days from the silking date to the harvesting date was 26 for the preceding crop and 46 for the succeeding crop. The sums of the temperature from the sowing date to the silking date were 1,512℃ for the preceding crop, 1,246℃ for the succeeding crop. The sums of the temperature from the sowing date to the harvesting date were 2,198℃ for the preceding crop and 1,951℃ for the succeeding crop. The dry matter yield of the preceding crop (1,637 kg/10a) was similar to that of the succeeding crop (1,565 kg/10a). The dry matter yields of Sinhwangok2 (1,673 kg/10a), Sinhwangok (1,660 kg/10a) and Kwangpyeongok (1,579 kg/10a) were similar to those of the preceding crop. The dry matter yields of Sinhwangok (1,669 kg/10a) and Kwangpyeongok (1,651 kg/10a) were similar to those of the succeeding crop and Sinhwangok2 (1,374 kg/10a) was the lowest among the three corn varieties. The total digestible nutrients (TDN) yield of the preceding crop (1,135 kg/10a) was similar to that of the succeeding crop (1,037 kg/10a). The TDN yields of Sinhwangok2 (1,183 kg/10a), Sinhwangok (1,158 kg/10a), and Kwangpyeongok (1,063 kg/10a) were similar to those of the preceding crop. The TDN yields of Sinhwangok (1,150 kg/10a) and Kwangpyeongok (1,100 kg/10a) were similar for the succeeding crop and Sinhwangok2 (970 kg/10a) was the lowest among the three corn varieties. The total dry matter yields of Sinhwangok (3,329 kg/10a) and Kwangpyeongok (3,230 kg/10a) were similar, but Sinhwangok2 (3,047 kg/10a) was the lowest among the three corn varieties. The total TDN yields of Sinhwangok (2,307 kg/10a), Kwangpyeongok (2,162 kg/10a), and Sinhwangok2 (2,152 kg/10a) were similar. It was concluded that Sinhwangok and Sinhwangok2 have high TDN yields as well as early maturity, and therefore are advantageous for direct continuous monocropping.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.4
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• pp.253-258
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• 2002

NC+4880, a forage com hybrid, is bred by NC+hybrids Co. in US, and Gast 8396 IT is by Garst Seeds Co. We have tested these two cultivars in Suwon and Chonan over three years to test their regional yield trial. Through above experiments, the excellence is testified, in result, they are determined as new recommended cultivars by NACF. The main characteristics of these cultivars are as tallows ; 1. NC+4880 a. The seed coat is yellow, the mean tasseling date is 7th of July and it takes about 74 days from emergence to tasseling date. This hybrid is a day ahead and the culm length is 242 cm, moreless shorter comparing with a check hybrid, Suwon 19. The ear height 117 cm which is short and its stay green is moderate. b. It shows resistance to H maydis, and MBSDV is barely observed and its stay green is moderate. c. The fresh yield, dry matter yield, and TDN yield per a ha are 55.4 tons, 18.3 tons, 12.4 tons, respectively, which are increased by 6%, 7%, and 9%, respectively, comparing with a check hybrid, Suwon 19. The percent ear among total dry matter yield is 50.9%. 2. Garst 8396 IT a. The seed coat is yellow, the mean tasseling date is 9th of July and it takes about 76 days from emergence to tasseling date. This hybrid represent a day delayed compared with a check hybrid, Suwon 19. The Culm length and the ear height are 275 cm, and 138 cm, respectively. b. It resists moderately to H. maydis, and highly resists to lodging in the field conditions. MBSDV is barely observed and its stay green is moderate. c. The fresh yield per a ha is 64.9 tons, dry matter yield, 20.9 tons, and TDN, 13.8 tons, respectively, which are increased by 25%, 23%, and 22% comparing with a check hybrid, Suwon 19. The percent ear among total dry matters is 43.3%.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.2
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• pp.94-99
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• 2013

Yanganok, a new single cross variety, was developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA in 2012. This hybrid, which has a high yield of grain was produced by crossing two inbred lines, KS164 and KS163. KS164 is the seed parent and KS163 is the pollen parent of Yanganok. It is a yellow-orange intermediate maize hybrid (Zea mays L.). After a preliminary yield trial and advanced yield trial of Yanganok (Suwon180) in Suwon for 2 years, a regional yield trial was carried out for its growth characteristics, and yields were determined at 4 different locations from 2009 to 2012, with the exception of 2010. It was named 'Yanganok'. The silking date of Yanganok is 2 days earlier than that of the check hybrid, Kwangpyeongok. Plant height of Yanganok is similar to Kwangpyeongok, but its ear height ratio is higher than that of Kwangpyeongok. It has resistance to lodging. Stay-green features of Yanganok are similar to those of Kwangpyeongok. The ear ratio of Yanganok is similar to Kwangpyeongok. It has moderate resistance to southern leaf blight (Bipolaris maydis) and strong resistance to northern leaf blight (Exserohilum turcicum). It has moderate resistance to black streaked dwarf virus (BSDV), ear lot and corn borer. The dry matter yield of Yanganok, 17.45 ton/ha, was similar to that of Kwangpyeongok. The total digestible nutrients (TDN) yield of Yanganok, 11.96 ton/ha, was similar to that of Kwangpyeongok. The grain yield of Yanganok, 8.32 ton/ha was similar to that of Jangdaok. Seed production of Yanganok went well due to a good match during crossing between the seed parent, KS164, and the pollen parent, KS163, in Yeongwol, and F1 seed yield was 1.79 ton/ha. Yanganok would be a suitable cultivar to all plain areas in the Korean peninsula.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.2
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• pp.137-144
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• 2015

This study was carried out to investigate the growth characteristics, yield, and chemical compositions of corn hybrids for silage according to the drainage depths in a lowland paddy field. The experimental design was arranged in a randomized block design with four treatments and three replications. The drainage depths of the four treatments were 0 cm, 20 cm, 30 cm and 50 cm. Tip-filling degree, ear length, and ear circle were higher in the 30 cm and 50 cm treatments compared with the other treatments (p < 0.05); but the plant length, leaf length, leaf width, ear height, stem diameter, and stem hardness were not significantly different (p < 0.05). The brix was higher in the order of 20 cm > 0 cm > 50 cm > 30 cm treatment. The fresh yield, dry matter yield, and TDN yield increased as the drainage depth increased (p < 0.05). The crude-protein and crude-ash content were highest in the 50 cm treatment (p < 0.05), but the crude-fat, NDF, ADF, and crude-fiber levels were not significantly different (p < 0.05). The total mineral content was higher in the order of 0 cm > 30 cm > 20 cm > 50 cm treatment (p < 0.05). Fructose, glucose, and sucrose were highest in the 20 cm treatment. The total amino-acid (EAA + NEAA) content was the highest in the 50 cm treatment. Based on these results, greater drainage depths increased the yield and feed value of silage corn.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.4
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• pp.396-399
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• 1989

Pearl millet (Pennisetum americanum (L.) Leeke) is a promising forage crop that is resistant to biotic and abiotic stresses, and has a capability to grow well not only in the fertile soil, but also in the poor and dry soil, The objective of the study was to investigate the effects of increased fertilizer application level on the productivity and Quality of pearl millet in the old and newly reclaimed upland soils of Suwon, Chungju, Jeonju, Jinju and Jeju in Korea from 1986 to 1988, Plant height, green fodder yield, protein content and digestibility were increased by the increased fertilizer application level. However, the increased fertilizer application caused lodging, so that the plants grown above one meter in canopy height would be desiable to be clipped remaining 20cm above the ground surface before lodging, and fed to cattle, Mean green yields of the N 45-60kg/l0a application were 12.7-13.4t/l0a in the old upland soil. Increased phosphorus and potash fertilizer application also increased productivity, especially with potash fertilizer effect being higher than that of phosphorus fertilizer, In the newly reclaimed upland soil, improved and doubled fertilizer application plot of 60-60-40-4000kg/10a in N-P$_2$O$\sub$5/-K$_2$O-Compost was 38％ higher being 12.6t/10a of green fodder yield as compared with standard fertilizer application plot, Pearl millet productivity and Quality were higher than those of maize and sorghum/sudan grass hybrids, particularly in green fodder yield, protein content and digestibility.