• Asian Journal of Turfgrass Science
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• v.26 no.2
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• pp.116-122
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• 2012

The study was conducted to know whether turfgrass wear tolerance, growth, and quality could be improved by the application of silicon and potassium. First, turf responses to silicate and potassium were evaluated by several parameters such as, turf visual quality, root length, shoot density, and dry weight under the field condition. Second, turf responses to traffic frequencies were examined by turf growth (root) length, shoot density and dry weight) and soil hardness under the field condition. Finally, under traffic stress condition, the effects of silica and potassium application on wear tolerance were evaluated through the methods described above. Creeping bentgrass (Agrostis stolonifera) rooting were significantly improved by silica. The root length was enhanced by an increase in potassium silicate application. Certain level of light traffic is beneficial while frequent traffic cause serious adverse effect on visual quality of bentgrass. Under a traffic stress condition with 10 times of footing a day for 30 days, silica and potassium increased turf visual quality by 6.38% and 10.25% respectively when compared to the control. Silica and potassium treatment on trafficked plot increased turf visual quality by 11.4% and 10.2% respectively in comparison with the control with significant reduction of wear injury from the traffic. A co-application of potassium silicate with potassium sulfate provided the enhanced visual quality of turf as compared to application of silica or potassium fertilizer, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.4
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• pp.74-83
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• 2011

In this study, to estimate the transforming (runoff and leachate) rate of the livestock resources applying to agricultural crop land as fertilizer, field scale test was conducted and the results were obtained as follows. According to results of livestock resources effect to agricultural land, the total amount of harvested crop from testing bed was $0.437kg/m^2$, and nutrient contents were $0.024{\pm}0.006%$ and $0.020{\pm}0.004%$ for N and P, respectively. Dynamics of contaminants in the livestock resources to be supplied to agricultural crop land showed that concentrations were continuously decreased to the level of blank test bed until 60 days of planting. The amount of runoff from farm land showed the tendency to increase according to the increase of rainfall intensity. Run-off ratio of 10mm/h rainfall intensity for agricultural land showed that each contaminant concentration was increased due to rainfall intensity with 8 mm/h, specifically SS showed the highest increase.

• Journal of Animal Environmental Science
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• v.1 no.2
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• pp.173-178
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• 1995

The aim of this study was to describe the NO$_3$ leaching in grassland ecosy-stems. Field study was performed in the southwestern district of Germany from 1991 to 1993. The study included 3 different slurry application, conventional slurry application, 50% reduced slurry application and without slurry application. On each plot were installed 3 ceramic cups at 120cm depth. Samples were collected twice a month and analysed for NO$_3$ colorimetrically using a Tecator Auto-Analyzer. Percolation was calculated as the difference between precipitation and potential evapotranspiration. The NO$_3$ concentration in soil water was remarkably variable during the year. The average NO$_3$ concentration during the experiment was the lowest (8.5mg/l) without slurry application and the highest with 240kg N/ha cattle slurry (25.3mg/l). the NO$_3$-N leached per year were respectively 29, 23, and 12kg/ha in case of 240, 120 and 0kg N/ha when cattle slurry was applied. The conventional feeding density of cattle husbandry in the district caused the NO$_3$ contamination in ground water. When the amount of cattle slurry applied was reduced to 50%, the NO$_3$ loading in ground water was reduced greatly. Therefore, the reduction policy of cattle slurry can positively contribute to the prevention of the NO$_3$-contamination in groundwater.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.3
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• pp.99-107
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• 2013

In this study, field scale test was conducted to estimate the TMDL coefficients (runoff and leachate:(${\beta}4$)(${\beta}5$)(${\beta}8$)) for the livestock resources applying to agricultural crop land as fertilizer, and the results were obtained as follows. Each waste reduction coefficient(${\beta}4$) was shown to be in the range of 0.94~0.75 for public waste treatment plants and 0.99~0.83 for private waste treatment in the analysis of BOD, COD, SS, T-N, T-P, TOC. Thus private plants showed higher rate. Waste treatment discharge into the land coefficient (${\beta}5$) was also shown to be in the range of 0.4.~0.24 for public plants and 0.75~0.16 for private plants, so it is much lower than other coefficients. However SS and T-P were shown to be much higher for land discharge in private plants than in public plants. Treatment coefficient in the public plants (${\beta}8$) appeared to be average 0.75 for T-P but over 90% treatment efficiency and also large deviation were observed due to 0.2 of some other treatment plants.

• Korean journal of applied entomology
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• v.14 no.3 s.24
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• pp.111-131
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• 1975

The study has been carried out to investigate the occurrence, damage, characteristics of the pathogen, environmental conditions affecting the disease outbreak, varietal resistance, forecasting, and chemical control of bacterial leaf blight of rice in Korea since 1964. Bacterial leaf blight of rice became a major disease in Korea since 1960. A correlation was found between the annual increase of epidemics and increase of cultivation area of susceptible varieties, Jinheung, Keumnampung etc. Areal damage within the country showed that the more was at southern province, Jeonnam, Gyeongnam and western coast, and at flooded rice paddy. Yield reduction directly related with the amount of infection on upper leaves at heading stage. Fifty per cent of reduction resulted when the lesion area was more than 60 per cent. Less than 20 per cent of lesion area, however, was not affected so much on yield loss One hundred and six isolates collected from all over the country were classified as 8 strains by using 4 different bacteriophages in 1973. It was, however, only two in 1965. There were some specificities on varietal distributions among the strains such as that the Jinheung attacked mainly by strain A, B, C and I, those attack Kimmaze were A, B, H and I. Most strains were found from Tongil except D and E, whereas Akibare was only variety that attacked by strain E. Low temperature, high humidity, heavy rainfall and insutficient daylight favored the disease epidemics. Especially, typhoon and flooding at heading stage were critical factors. The earlier transplanting the more disease was resulted, and more nitrogen fertilizer application accerelated the diseased development in general. The resistance to the disease varied by growing stage of the sane plants. All of recommended varieties in Korea were susceptible to the disease except Norm No. 6 and Sirogane which moderately resistant. The pathogen, Xanthomonas oryzae, was detectable from extract of healthy seedlings that were grown in the field with an heavy infection previous year. The more bacteriophage in irigation water resulted the more disease outbreak, and the existence of more than 50 bacteriophages in 1ml. of irrigation water were necessary to initiate the disease out break. The curves representing occurrence of bacteriophages and disease outbreak were similar with 15 days interval. The survey of bacteriophage occurrence can be utilized in forecasting of the disease two weeks ahead of disease outbreak. Three applications of chemicals, Phenazin and Sangkel, in weekly intervals at the early satage of out-break depressed the symptom development, and increased yield by 20per cent. Proper period for the chemical application was just before the number of bacteriophage reaches 50 in 1ml. of irrigation water.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.4
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• pp.21-27
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• 2014

Pig slurry has been considered as environmental waste to be treated in an appropriate manner. Moreover, water-born pollution loads by agricultural non-point source(NPS) pollution are expected to become intensified due to ongoing precipitation change. This study was conducted to develop a best management practice to reduce NPS pollution load by agricultural activity with pig manure compost. An eco-friendly way, small drainage pond, was suggested in this study to avoid direct drainage of agricultural runoffs and eventually reduce the amount of pollutants discharged into the surrounding aqua-environment. A small pond($12m^2$) was constructed at the corner of a rice paddy field($17,15m^2$) located in Suwon, Korea. Water was allowed to drain only via a small drainage pond. Sampling was repeatedly made at two locations, one from an entrance and the other from an exit of a pond, during the rice cultivation period(May to October, 2013). Generally, sampling was made only when runoff water drained through a pond, such as during and/or after rain(irrigation). The water quality analysis showed that all quality parameters(SS, $COD_{Mn}$, T-N, and T-P) were improved as water passed through the pond. The amount of runoff water was reduced by 67.8%. Suspended solids and $COD_{Mn}$ concentrations were reduced by 79.8% and 71.9%, respectively. In case of T-N and T-P amounts, the reduction rates were 73.6% and 74.9%, respectively. Our data implies that agricultural NPS pollution from rice paddy fields with pig manure-based fertilizer can be effectively managed when an appropriate drainage water management practice is imposed.

• Journal of Animal Environmental Science
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• v.10 no.1
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• pp.1-10
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• 2004

A field-scale(8.6${\times}$2.5${\times}$2.4 m) and pilot-scale(1.39${\times}$0.89${\times}$0.89 m) thermophilic aerobic oxidation (TAO) units were installed to investigate the volume reduction efficiency of slurry, by varying the aeration and treatment temperature of swine manure, and the collected liquid was evaluated as a liquid fertilizer. In the field-scale unit, the aeration level and numbers of foam breakers made different effects on the slurry volume and temperature in the TAO system. The experiments were peformed for three cases, using different levels of aeration and numbers of foam breakers: Treat-A (aeration rate; 120 ㎥ air/hr using 2 air pumps and 2 foam breakers), Treat-B (aeration rate; 180 ㎥ air/hr using 3 air pumps and 3 foam breakers) and Treat-C (aeration rate; 180 ㎥ air/hr using 3 air pumps and 4 foam breakers). With the same input volume (5 ㎥/day) of swine manure slurry, the resulting liquid levels, temperatures and evaporation rates were 50∼100 cm, 31∼$64^{\circ}C$ and 55 $\ell/m^2$/day for Treat-A; 40∼90 cm, 29∼$52^{\circ}C$ and 75 $\ell/m^2$/day for Treat-B; and 40∼70 cm, 45∼$54^{\circ}C$ and 120.0 $\ell/m^2$/day for Treat-C. In the pilot-scale unit, semi-continuous flow of swine manure slurry was introduced. 50 $\ell$ every 2hr(T-1), 50 $\ell$ every 3hr(T-2), 40 $\ell$ every 2hr (T-3) and 60 $\ell$ every 4hr (T-4) within 24 hours, in order to find the maximum slurry volume reduction conditions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.479-485
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• 2002

This study was conducted in order to elucidate the effects of nitrogen level and split application method, and shading treatment during reproductive stage on sink formation. Japonica variety Choocheongbyeo and Hwaseongbyeo and indica$\times$japonica cross type variety Nampoongbyeo were used. Five levels (6 to 30 kg/10a at 6 kg/10a interval) of nitrogen fertilization, and two split application methods (50-25-25% and 30-30-40% as basaltillering-panicle fertilizer) for each nitrogen treatment were applied. In addition shading treatments (shading rate, 65%) were performed for N 12 kg/10a and 24 kg/10a plot. Shading were applied for 30 days from panicle initiation to heading, 15 days from panicle initiation and 15days before heading. Panicle per square meter, and primary rachis branches per panicle and differentiated number of secondary branch per panicle increased according as applied nitrogen amount increased up to 18 to 24 kg/10a, and there was no significant difference between two nitrogen application methods. Primary rachis branch and secondary branch per square meter also increased according as the amount of applied nitrogen increase up to 18 to 24 kg/10a, and there was no significant difference between nitrogen application methods. Panicle per square meter and primary rachis branch per panicle were significantly decreased due to shading treatments only in Choochengbyeo. In all varieties, shading reduced secondary rachis branch per panicle significantly and the reduction was greatest in 30 days shading during reproductive stage. Spikelets per square meter increased according as the amount of applied nitrogen increases up to 18 to 24kg/10a, but showed no move increase above this nitrogen application level. Significant difference was not shown between nitrogen split methods. Spikelets per square meter also decreased significantly due to shading treatment during reproductive stage, showing the greatest reduction by 30 days shading during reproductive stage, and the least by 15 days shading during booting stage. The variation of spikelets per square meter was influenced greatest by the variation of panicles per square meter and spikelets per secondary rachis branch.

• Journal of Bio-Environment Control
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• v.27 no.2
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• pp.140-146
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• 2018

This research was conducted to determine the influence of incorporation levels of sulfur into a coir dust+pine bark medium (1:1, v/v) on the changes in the bicarbonate ($HCO_3{^-}$) concentrations and pH of soil solution, crop growth, and nutrient uptake of 'Ssanta' strawberry. In the preparing of the mixed medium, sulfur powder was added with the rate of 0 (control), 0.23, 0.45, 0.90, and $1.80g{\cdot}L^{-1}$ and Hoagland nutrient solution containing $240mg{\cdot}L^{-1}$ $HCO_3{^-}$ was supplied during the crop cultivation. The growth measurements and tissue analysis for the determination of nutrient contents were carried out 140 days after solution application and the soil solution analysis was performed every two weeks. As the level of sulfur was elevated, the overall growth of mother plants became better showing that the growth indexes except chlorophyll contents were the lowest in control treatment but the statistical differences were not found among the three treatments of $0.45g{\cdot}L^{-1}$ or higher sulfur. The higher the levels of sulfur incorporation, the higher the occurrence of runners and the growth of daughter plants. The length of the runners and the number of daughter plants occurred per mother plants were higher in the treatments of 0.90 and $1.80g{\cdot}L^{-1}$ than the three treatments of 0, 0.23, and $0.45g{\cdot}L^{-1}$, but the statistical differences were not observed between the 0.90 and $1.80g{\cdot}L^{-1}$ treatments. The rose of pH and $HCO_3{^-}$ concentrations in soil solution of root media continued all the cropping period, but those decreased slightly in the treatments of $0.90g{\cdot}L^{-1}$ or higher. The soil solution concentrations of $K^+$ and $PO_4{^3-}$ in the treatments of 0.90 and $1.80g{\cdot}L^{-1}$ was lower than those in other treatments and the statistical differences in the $Ca^{2+}$ and $Mg^{2+}$ concentrations were not observed among all treatments. The nutrient contents in tissue analyzed in this experiment were the lowest in the control treatments and those increased as incorporation rates of sulfur were elevated. Above results indicated that when 'Ssanta' strawberry is grown hydroponically and the root medium is coir dust and the pine bark (5:5, v/v) mix, the sulfur incorporation rate as pre-planting fertilizer has to be higher than $0.9g{\cdot}L^{-1}$ root medium to reduce the $HCO_3{^-}$ injury.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.14
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• pp.173-189
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• 1973

The followings are the results obtained in a series of experiments concerning of the varieties, the short-day-treatment, the fertilizer application, and the planting space of soybean, which were carried out to investigate the methods best suited for cultivating green soybean as the preceding crop of the rice. in the paddy-field in the middle parts of Korea at the practice farm attached to Agriculture College of Kon Kuk University in 1972. 1. Though the varieties of soybean was planted on the hot-bed on March 15 and then set in the main plot, none of them did flower within May 15, which is the limit time of flowering in growing soybean as the preceding crop of the rice in the paddy-field without the short-day-treatment being applied during raising seedlings. 2. The earliest-maturing variety groups such as HOKKAl#l, WASEMIDORI, YAEHUSANARI, MIT AKARAHAKUCHO, and VERDE flowered within May 15 by the short-day-treatment during raising seedlings. 3. The optimum hours of the day length was known to be 7 to 9 in the medium-maturing and late-maturing variety groups and 7 to 11 in the early-maturing and the earliest-maturing variety groups in the case of appling the short-day-treatment for 10 days from the beginning of the primary regular compound leaf development. 4 The optimum days in appling the short-day-treatment for 11 hours a day was recognized to be about 10 days regardless of the maturity of varieties. 5. Reduction of days required to flower by the short-clay-treatment, that is, light-sensitivity was remarkably higher in the medium-maturing and the late-maturing variety groups than in the earliest-maturing and the early-maturing variety groups. 6. The yield showed an increase of about 17 per cent in the case of appling the standard amount of nitrogen(4.0 kg/10 a), but it tended to reduce on the contrary in appling the increased amount of nitrogen. 7. The application of increased amount of phosphate had less significant effect on the yield increase than in the case of application of its standard amount( 4.0 kg/l0 a). 8. When the number of transplantation plant was changed from 54 to 130 per 3.3 $m^2$, the yield in 130 plant plot was about two times so higher than in 54 plant plot that the effect of close planting cultivation on the yield was proved to be remarkable. 9. Conditions possible for cultivating green soybean as the preceding crop of the rice in the paddy-field in the middle parts of Korea are turned to be as follows: (a) to plant the earliest-maturing-variety groups on the hot-bed on March 15. (b) to apply the short-day-treatment by 11 hours a day for 16 days from April 16, which is about the time when the primary regular leaf begin to develop. And it was, found to be a most remarkable in the increased yield that apply nitrogen 4.0 kg, phosphate 4.0 kg, and potassium 6.0 kg per 10 a as basic manuring totally and apply the close planting by 130 plants per $3.3{m^2}$(50 cm $\times$ 5 cm).