• Journal of Korean Society of Environmental Engineers
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• v.34 no.11
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• pp.720-728
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• 2012

In general, nonpoint pollutant of a watershed is drained out in the form of storm water runoff during rainfall events. As the bulk of the nonpoint pollutant is in adsorbed form on particulate matters, in order to understand the behavior of nonpoint pollutant it is essential to grasp the characteristics of particulate matters in rainfall runoff. Though, previous studies for the relationship between the runoff characteristics of pollutants and the size distribution of particulate matters are very rare. In this study, a small non-urbanized area (basin area of 52.8 ha) with various landuse types including paddy, dry fields and forest was selected and investigated in detail for the runoff properties of each pollutant during several rainfall events. The correlation and effects between particulate matters and nonpoint pollutant were analyzed quantitatively. As a result, the significant first flush was observed on each event and it became clear that fine particulate matters ($80{\mu}m$ or less) has contributed in the runoff process of nutrients and heavy metals. Organic matters ($BOD_5$, TOC), nutrients (TN, TP) and several heavy metals (Al, Cr, Cu, Fe, Hg and Zn) represented high correlations with SS (total), VSS, SS (d < $20{\mu}m$) and SS ($20{\mu}m$ $$\leq_-$$ d < $80{\mu}m$). On the other hand, $COD_{cr}$, Cd, Mn and Pb did not show clear correlations with the behavior of particulate matters. Therefore, we have to examine the introduction of nonpoint pollution mitigation facilities considering the facts that nonpoint pollutant runoff process has high correlation with the behavior of particulate matters and is changeable based on the target pollutants.

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.208-216
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• 2011

The purpose of this study was to find soil-amendment materials those support the growth of Kentucky bluegrass and reduce salt accumulation at the sand based growing media in saline conditions. Rootzone profile in columns consisted of 20 cm of top soil, 20 cm coarse sand as capillary rise interruption layer and 10 cm reclaimed paddy soil as the base of the profile. Top soils were mixtures of dredged sand (DS) and amendment with compositions of 90% sand + 10% peat moss (SP), 80% sand + 10% soil + 10% bottom ash (SSoBa), 80% sand + 20% soil (SSo), 90% sand + 5% peat + 5% zeolite (SPZ), and 80% sand + 20% bottom ash (SBa). The top soil mixtures of DS and amendments were treated with and without gypsum (Gp). The columns were soaked into 5 cm depth saline water reservoir with the salinity level of $3-5dSm^{-1}$. Irrigation of $2dSm^{-1}$ saline water with rate of $5.7mm\;day^{-1}$ was applied by 3 day interval. Application of zeolite decreased SAR, application of gypsum decreased ECe of the sand amended by peat + zeolite and decreased the SAR of sand amended by bottom ash. The SP and SSoGp resulted in higher clipping dry weight of Kentucky bluegrass. The SSoGp and SPZGp showed longer root lengths. The SP and SBaGp showed higher visual quality. Addition of gypsum to soil and bottom ash treatments resulted in the increased shoot growth, whereas additional gypsum to the treatments of peat, soil and zeolite increased the root growth of Kentucky bluegrass.

• Korean Journal of Organic Agriculture
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• v.24 no.2
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• pp.235-251
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• 2016

After carrying out on-the-spot observation targeting each farmhouse of large-scale environment-friendly agricultural district (LEAD), Suncheon, Sancheong, Jangheung, Yeongam, Hamyang, Okcheon, and Jeongseon in 2015, only one LEAD, a farmhouse in Jangheung had used sustainable compost coming out under their own non-antibiotic livestock. The soil pH and EC at a depth of 0-20 cm in the seven LEADs were ranged between 5.3-6.6 and $0.4-1.2dS\;m^{-1}$, respectively, with 0.03- 0.27% for T-N concentration, $22-322mg\;kg^{-1}$ for P, and $0.05-0.29mg\;kg^{-1}$, which were, in particular, low a farmhouse in Jeongseon. When intensively surveying on each farmhouse of Suncheon, Jangheung, and Okcheon for a growing period, seasonal soil pH was maintained above 6.0 and high in a farmhouse in Okcheon, with similar soil EC observed among the three LEADs. Seasonal soil T-N was 0.1% higher on the farmhouse in Suncheon than other two LEADs, with higher seasonal soil P observed on the farmhouse in Okcheon and higher soil K in the Jangheung. T-N concentration in rice (Oryza sativa L.) crops was the highest in Jangheung, and concentrations of T-N, P, and K decreased in a season. Plant height and number of tillers per hill were the highest on the farmhouse in Okcheon, where was similar or low plant diameter and SPAD levels compared to other two LEADs. Dry weight (DW) before harvest was ranged between 52-63 g, and DW, rough rice yield (kg), brown rice/rough rice (%), brown rice yield (kg), head rice (%), and broken rice (%) were not significantly different among the three LEADs. Total annual gross production ha-1 was the highest on the farmhouse in Okcheon (16,230,000 won) planting with high class of variety, 'Milky queen' at early maturation, which was expected to be increased on an agricultural income. However, high amount of fertilizer was applied for growing the following crops on the farmhouse in Okcheon, affecting the highest balance of T-N, P, and K more than $200kg\;ha^{-1}$.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.1
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• pp.8-15
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• 1992

An experiment was conducted to find out effect of soil water condition on shoot and root growth and P, K uptake by soybean plants. Soybean plants were grown under different soil water table levels, 20cm, 40cm and 60cm below the soil surface using minirhizotron with 20cm in diameter, and well irrigated and water stressed conditions using 1/2000a Waganer pots. Three soybean plants, Paldal culfivar, were grown and sampled at the early growing period, 37 days after planting, and at the harvesing period, 115 days after planting. Shoot and root growth were restricted by water stresed condition and by excessive soil water condition with the 20cm water table. Little difference in shoot and root growth were found between well irrigated condition and 40cm or 60cm water table conditions. The P and K contents in shoot under water stressed condition were higher than well irrigated condition at the early growing period but reversed at later harvesting period. The dry weight and length of roots were more severely restricted by water stress than those of shoots. Root morphological difference was found by anatomical observation. Normal cortex was developed under the well irrigated condition, while abnormal cortex with aerenchyma formed by lysis under excessive water conditions of 20 or 40cm water talbes. Aerenchyma was formed at outer skirt of pericycle. Role of formation of aerenchyma of soybean roots might be an adaptation to excessive soil water condition and possibly related to survival of soybean roots growing under near flooding condition on dikes of paddy lands.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.4
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• pp.287-296
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• 2007

The experimental work was conducted to determine the growth characteristics and yield of whole crop rice (cv. Suwon 468 and cv. Chuchungbeo) and soil properties using various type of livestock manure application on rice paddy land for 3 years ($2003{\sim}3005$). Compared Suwon 468 and Chuchungbeo, Suwon 468 has longer plant height and more DM yield than that of Chuchungbeo. Among livestock manure type, plant height was longer in order of liquid swine manure (LSM) > composted swine manure (CSM) > chemical fertilizer (CF) > composted cattle manure (CCM). Number of branch on Chuchungbeo had more than that of Suwon 468. Among livestock manure type, number of branch had more in order of LSM > CSM > CF > CCM. DM yield of whole crop rice (WCR) was affected by various types of livestock manure application and increased in order CSM > CCM = LSM. DM yield on the effects of application level of LSM was highest in LSM 75% + CF 25%. Plant diseases such as rice blast, damage by insect, smut, sheath blight occurred in LSM and CSM and there was not significantly different among application level of LSM. The nitrogen content of WCR by CSM was the highest of all treatments and the ripened ratio by CSM was in contrary order. Moreover the feed value of WCR was not significantly different among treatments. Soil pH, organic matter and total nitrogen was not different by LSM application whereas phosphorus content increased by LSM application. Cu and Zn content increased by LSM and CSM application and were not different by CCM as compared to control plots.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.1
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• pp.57-62
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• 2015

"Nokyang" (Hordeum vulgare L.), a new whole-crop silage barley cultivar, was developed by the breeding team at the Department of Rice and Winter Cereal Crop, National Institute of Crop Science, RDA, Korea in 2012. It was derived from combining "Nagyoung" and breeding line "SB77368-B-145". Among the combinations made in 2001, a promising line, "SB01T2017", showed good characteristics in terms of potential forage yield in the yield trial at Iksan from 2007 to 2009. In 2009, the promising line was designated as "Iksan457" and placed in regional yield trials at six locations around Korea for three years from 2010 to 2012, and was released under the name of "Nokyang." It has the growth habit of a group III creeping plant type, with a light-green leaf and common spike. Its average heading and maturing dates were on May 6 and June 4, respectively, which were later than cultivar "Youngyang." "Nokyang" also showed strong winter hardiness, and a resistance to shattering and barley yellow mosaic virus (BaYMV) similar to those of the check cultivar. The best thing among the traits of one is a new good quality with the plant green at the latter growing period. The average forage dry matter (DM) yields in the regional yield trial were about 12.8 and 11.5 MT $ha^{-1}$ in upland and paddy field, respectively, which were higher than those of the check cultivar, by 7% and 2%, respectively. This cultivar would be suitable for an area of the Korean peninsula where the daily minimum temperature in January is above $-8^{\circ}C$.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.1
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• pp.75-84
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• 2011

This study was conducted to investigate the effect of harvest stage of corn on the quality of square baled corn silage manufactured with corn grown in paddy land of Department of Animal Resources Development, National Institute of Animal Science, RDA from 2009 to 2010. Corn "Kwangpyungok" was harvested at three different growth stages (milk, yellow ripen and ripen stage) and ensiled at each harvest time. Square baled corn silage was manufactured by use of square silage wrapping compressor. Each treatment was replicated three times. The content of crude protein (CP) of corn in square baled corn silage decreased with delayed maturity, but the content of ADF (acid detergent fiber), NDF (neutral detergent fiber), TDN (total digestible nutrient) and in vitro dry matter digestibility (IVDMD) were not changed. The content of moisture, pH and the nutritive values at three different harvest stages were not influenced by the method of silage manufacture and inoculant. The content of lactate of square baled corn silage harvested in milk stage of corn was significantly increased, as compared with that of round baled corn silage (P<0.05), but in stage of yellow ripen was significantly decreased (P<0.05). The content of acetate in square baled corn silage significantly decreased with delayed harvest maturity, as compared with that of round baled corn silage (P<0.05). Flieg's score of square baled corn silage harvested in milk stage of corn was slightly higher than that of round baled corn silage, but Flieg's scores in yellow ripen stage and ripen stage were not influenced by the method of silage manufacture. Flieg's score with delayed maturity was not influenced by the method of silage manufacture and inoculant. The manufacture of square baled corn silage was proved to be suitable for the fermentation of corn silage. Therefore, this study suggest that square baled corn silage can be a way of new silage manufacture technique.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.4
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• pp.243-249
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• 2019

A barley(Hordeum vulgare L.) cultivar 'Youjin' with hooded spike type having good silage quality was developed at National Institute of Crop Science, RDA in 2016. 'Youjin' showed both high yielding and cold resistance through the preliminary and advanced yield trials(PYT, AYT) from 2012 to 2013. We conducted regional yield trials(RYT) of 'Youjin' in six locations around Korea for three years from 2014 to 2016. It had erect plant type, growth habit of II, the green leaf and hooded awn type. In the paddy field its heading date was April 24 and the maturing date was May 25. Plant height was 99 cm and the number of spikes per ㎡ was 696. It has high rate of leaf blades, resistance to BaYMV(Barley Yellow Mosiac Virus) and good winter hardiness. The average dry matter of Youjin was about 17.2 MT ha^-1 in the field. And feed quality of 'Youjin' was 10.6% of crude protein content, 24.8% of ADF(Acid Detergent Fiber), 43.5 % of NDF(Neutral Detergent Fiber), 69.1% of TDN(Total Digestible Nutrients). And also 'Youjin' had grade I of silage quality.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.25-31
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• 1986

This study was conducted to determine the effects of 5 years continuous application of compost and rice straw with the different rates of nitrogen fertilizer on physico-chemical properties of paddy soils and yield of rice. The results obtained were as follows; 1. The yield of rice was 7 and 4% higher at straw and compost treatment compared to the non-application of organic matter. The rate of yield response for nitrogen fertilizer was lowered as the amount of nitrogen application increased under the condition of organic matter application. 2. Dry mayer weight and total nitrogen content of rice plants were increased in the order of straw > compost > non-application of organic matter. Above two factors were positive correlations with yield but total nitrogen content was negative correlation with ripening rate. 3. $NH_4-N$ in the soil was higher at plot applicated with compost and straw than non-application. It was positive correlation ($r=0.62^*-0.79^{**}$) with total nitrogen content in rice plants from 15 days after transplanting to heading stage. 4. The physical properties of soil, hardness and infilteration rate, after 5 years experiment, were improved in the order of straw > compost > non-application of organic matter. Organic matter content in the soil was decreased 0.1% on the straw treatment after 4 years, 0.1% on the compost after 3 and 4 years, and 0.1% on the non-application every years.

• Korean Journal of Weed Science
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• v.3 no.2
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• pp.156-165
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• 1983

This experiment was conducted to find out the effect of competitive duration and density of Cyperus serotinus Rottb. on rice growth and yield. In plant height of both rice and flatsedge, the compacter density of flatsedge, the higher was plant height. Rice in the 50 days competition with flatsedge had shorter culm than in other competition plots at all density. The panicle number was affected during the tillering stage. The spikelet number per panicle was influenced from 25 days to 50 days after transplanting. Grain maturity ratio and 1,000 grain-weight didn't decrease under competition before 50 days after transplanting. The competition during the tillering stage to the young panicle initiation stage decreased significantly rice yield. The rice competed with low density of flat sedge showed small decrement of yield and its components. The period reaching to maximum stem number of flatsedge become shorter as flatsedge density increased. Number of flatsedge tubers competed with rice produced was 40.1, 16.8 and 11.4 times as much in 1: 1, 1:3 and 1:5 density ratio of rice to flatsedge, respectively. Flatsedge dry matter weight and rough rice yield had the relationship of Y = 601. 95-$0.67x^{**}$.