• Asian Journal of Turfgrass Science
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• v.11 no.3
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• pp.173-183
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• 1997

This study was conducted to develop an integrated disease management system against large patch disease. Attempts were made to estimate the effect of calcium hydroxide, silicate fertilizer and urea on the mycelial growth of Rhizoctonia sotani AG2-2 and the development of large patch in vitro and in vivo and to establish the most promising combination of fertilizer, fungicide and antagonistic microbes. 1.The mycelial growth of Rhizoctonia sotani AG2-2 were completely inhibited at 2,000, 1,000 and 3,000ppm concentration by calcium hydroxide, silicate fertilizer and urea, respectively. Inhibition effect of silicate fertilizer was the highest, but that of urea was the lowest compared with other treatments. 2.Treatment of calcium hydroxide at rate of l00g /$m^2$ was the most effective, and control effect appeared from 30 days after treatment in spring, which was better in autumn than in spring. Silicate fertilizer treated at rate of l00g /$m^2$, 200g /m$^2$, in spring and 50g /$m^2$ in autumn were very effective. Urea at rate of 30g /$m^2$ was more effective than 60g /m$^2$ and 120g /m$^2$. 3.The efficacies of mepronil and toclofos-methyl, applied twice in spring and once in autumn, were 83.8% in spring, which persisted to 70% in autumn compared with untreated plot. 4.The efficacies of Trichoderma harzianum were the highest by 55% in spring, but those of Bacillus amyloliquefaciens BL-3 and Peudomonas putida were the highest by 80% in autumn among other antagonists tested, when two organisms were applied twice in spring and once in autumn.

• Korean Journal of Plant Resources
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• v.14 no.1
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• pp.43-47
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• 2001

For the purpose of sweet potato varietal improvement, yulmi, shinyulmi, gunmi, hongmi and seonmi, whose source and sink are different one another, were cultivated at different amount of fertilizers, and then defoliation at initial stage of tuberous root weight increase on the relation of source and sink was observed as follows. The response of stem, leaf and tuberous root weight by amount of fertilizer and defoliation rate of sweet potato varieties was different. Stem and leaf weight increased along with heavy dressing by the following order; shinyulmi> seonmi> hongmi> gunmi> yulmi. Tuberous root number was the most at $N-P_2O_5-K_2O=60-70-190kg/ha$ amount of fertilizer, showing seonmi the most number. The number of stem, leaf and tuberous root increased along with the lowered rate of defoliation. In case of $N-P_2O_5-K_2O=20-30-90kg/ha$ amount of fertilizer, tuberous root weight increased by increase of stem and leaf weight up to 50% defoliation and the difference of stem, leaf and tuberous root number was low as defoliation rate increases. The total dry weight matter was the most at heavy dressing amount of fertilizer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.5
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• pp.294-299
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• 2000

Hairy vetch (Vicia villosa Roth) winter annual is very effective on reducing chemical nitrogen fertilizer for subsequent com by fixed organic green manure nitrogen fixed during hairy vetch growth. In this experiment, hairy vetch produced above-ground dry matter of 5 ton/ha, nitrogen yield 200 kgN/ha, at com planting on the average during 1997 and 1998. Changes in com yield and nitrogen uptake for two years were investigated after application of nitrogen fertilizer 0, 60, 120, 180, 240 kgN/ha on plot of winter fallow and hairy vetch green manure, respectively. Nitrogen status such as ear-leaf N%, SPAD value at silk and dough stage, and com yield decreased in proportion to reduction of nitrogen fertilizer at winter fallow, but nitrogen status and yield of com were not different among nitrogen fertilizer rate at hairy vetch green manure. Com yield (total dry matter) at 0 kgN/ha plot of hairy vetch was 22, 20 ton/ha in 1997, 1998, respectively and com could produce more dry matter 9, 13 ton/ha by hairy vetch green manure compared with winter fallow under the condition of no nitrogen fertilizer in 1997, 1998, respectively. Com yield (total dry matter) at 60kgN/ha of hairy vetch green manure was higher than that of high N fertilizer rate such as 180, 240 kgN/ha of winter fallow. Nitrogen uptake of com at plot of hairy vetch-no nitrogen fertilizer slightly decreased than at plot of hairy vetch - nitrogen fertilizer, but com absorbed more nitrogen of 141, 159 kgN/ha by hairy vetch green manure compared with winter fallow under no nitrogen fertilizer condition in 1997, 1998, respectively. Nitrogen fertilizer reduction for com by hairy vetch green manure was 149, 161kgN/ha in 1997, 1998, respectively. Still more, com could absorb more soil nitrogen by nitrogen fertilizer 60kgN/ha of hairy vetch green manure than by high nitrogen fertilizer such as 180, 240 kgN/ha at winter fallow. It is concluded that nitrogen fertilizer for corn could be reduced by winter cultivation and soil incorporation of hairy vetch at com planting.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.3
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• pp.147-152
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• 2001

This study was carried out to investigate the effect of application time and amount of liquid pig manure on growth and yield of rice plant and infiltration water quality. Liquid manure treatment with higher application rate and closer application time to transplanting time showed higher plant height and number of tiller at panicle formation stage, but it caused the plant disease and pest and lodging. In liquid manure treatment with higher application rate, number of panicles per hill and number of spikelets per panicle were higher but yield of rice was less than chemical fertilizer treatment due to low rate of ripeness and 1,000 grain weight. $NO_3-N$ concentration in infiltration water sample was increased with increasing application amount of liquid manure and closer application time to transplanting of rice plant. With consideration yield of rice and environment such as groundwater quality, the proper application amount were 150% and 100% of recommending N fertilizer level (11kg) at before winter and April or May treatment, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.3
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• pp.217-224
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• 2014

Ground-based remote sensing can be used as one of the non-destructive, fast, and real-time diagnostic tools for predicting yield, biomass, and nitrogen stress during growing season. The objectives of this study were: 1) to assess biomass and nitrogen (N) status of tobacco (Nicotiana tabacum L.) plants under N stress using ground-based remote sensors; and 2) to evaluate the feasibility of spectral reflectance indices for estimating an application rate of N and predicting yield of tobacco. Dry weight (DW), N content, and N uptake at the 40th and 50th day after transplanting (DAT) were positively correlated with chlorophyll content and normalized difference vegetation indexes (NDVIs) from all sensors (P<0.01). Especially, Green NDVI (GNDVI) by spectroradiometer and Crop Circle-passive sensors were highly correlated with DW, N content and N uptake. The yield of tobacco was positively correlated with canopy reflectance indices measured at each growth stage (P<0.01). The regression of GNDVI by spectroradiometer on yield showed positively quadratic curve and explained about 90% for the variability of measured yield. The sufficiency index (SI) calculated from data/maximum value of GNDVI at the $40^{th}$ DAT ranged from 0.72 to 1.0 and showed the same positively quadratic regression with N application rate explaining 84% for the variability of N rate. These results suggest that use of reflectance indices measured with ground-based remote sensors may assist in determining application rate of fertilizer N at the critical season and estimating yield in mid-season.

• Korean Journal of Weed Science
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• v.30 no.3
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• pp.258-265
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• 2010

The effects of organic-compound fertilizer on weed control and rice growth in the transplanting rice cultivation were researched in this article. The results showed that the growth of transplanted rice was promoted (the increased rate was 10.3~27.2%), but the plant number for Echinochloa crus-galli was controlled (the inhibition rate was 50.3~89.2%), besides, small amount of organic-compound fertilizer in controlling Aneilema keisak was highly effective when the transplanted rice was treated with 125~250 kg $10a^{-1}$ organic-compound fertilizer. Moreover, E. crus-galli, Monochoria vaginalis and A. keisak were inhibited largely by increasing the water depth (1~5 cm), whereas Eleocharis kuroguwai and other sedges weeds were not effected by water depth. Compared with the temperature of $20{\sim}35^{\circ}C$, the plant occurrence of E. crus-galli and M. vaginalis at high temperature was inhibited (the inhibition rate were 75.4~92.2% and 49.5%~81.6%, respectively). When the transplanted rice was treated with the above organic-compound fertilizer after 10day, the inhibition rate of plant occurrence for E. crus-galli and M. vaginalis was 33.7% and 23.3%, respectively. Similarly, in the later period of rice growth, the plant height and the numbers of tiller grew slowly in conventional soil in comparison with the soil treated with organic-compound fertilizer. It has been found that the rice yield in experimental soil was decreased by 4%. This result in the field experiment showed that organic material contents in conventional soil were lower than that in soil which used the organic-compound fertilizer. Weed control in experimental soil showed 60.5% lower effects than that in conventional soil.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.558-562
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• 2014

Cover cropping and liquid manure application are considered as effective ways to replace the use of chemical fertilizer in orchard. This study was conducted to investigate the effect of cover crop species and liquid manure application rate on green manure production, leaf mineral content, fruit quality and soil chemical properties in pear orchard. The treatments include rye and hairy vetch as cover crops, two liquid manure application levels based on N and $K_2O$ requirement on each cover crop species, and chemical fertilizer as control. Green manure production was higher in hairy vetch than in rye. K content of pear leaves and soil exchangeable K content increased in N based liquid manure application treatments. The yield was higher in rye + liquid manure and fertilizer treatments, and fruit quality was not different between the treatments. Taking all of these into account, rye + $K_2O$ requirement-based liquid manure application is recommended in pear orchard for not only sufficient nutrient supply but also prevention of any problem related with soil $K_2O$ accumulation in pear orchard in long-term perspective.

• Journal of the Korean Society of Tobacco Science
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• v.4 no.1
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• pp.29-35
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• 1982

Potassium deficiency symptoms were studied with flue-cured tobacco which was applied with different levels of compound fertilizer (10-15-20) ; 75kg, 100hg, and 125kg/10a. Ratio of N/$K_2O$ in leaves was increased from bottom to top stalk position due to the increase of nitrogen content in leaves. Nitrogen content in leaves was increased from stalk to tip as wall as from midrib to laminae, but vice versa in potassium content. Consequently, resulting in potassium deficiency symptoms in tip of leaves. Rate of reabsorption by rainfall during the latter part of growth was highest at top stalk position in case of nitrogen, but lowest in potassium. This observation was more evident with higher application rate of fertilizer. Nitrogen content of about 4 % in leaves of top stalk position applied with 125kg/10a was maintained up to 85days after trans planting. No increase in potassium in upper leaves was observed over the level of 100kg/10a fertilizer application. As the result, N/$K_2O$ ratio in leaves of top stalk position applied with 125kg/10a was kept at more than 1.0 up to 85days after transplanting, but it was less than 0.9 at 65days after tracts planting with less than 100kg/10a fertilizer application.

• Ecology and Resilient Infrastructure
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• v.5 no.1
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• pp.11-18
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• 2018

Phosphorous remains as one of the most limiting nutrients to plant growth, second only to nitrogen. Research on use of biochar as a soil amendment for available phosphorus in temperate calcareous soils has limited studies compared with to tropical acidic soils. An incubation experiment to assess phosphorous availability in a biochar amended calcareous soil under inorganic (Fused superphosphate, FSP) and organic fertilizer (bone meal, BM) and respectively, at the dose of 40, 80 and $120mg\;P\;kg^{-1}$ was carried out. Soil was incubated at $25^{\circ}C$ for 70 days. Results show that the rate of increase in available P was proportional to the fertilizer application rate with or without biochar amendment. Biochar did not have a significant effect on soils amended with either fertilizeron the values of available P. However, time had a significant effect (p<0.001) on the amount of available P during the incubation period. Inorganic fertilizer treatments had recorded high amount of available P with time compared to organic fertilizer treatments. Organic fertilizer treatment sample were significantly not different from control and for most of the incubation time biochar acted as a soil conditioner. Further research is required to understand the holistic and long-term effect of biochar.

• Radioisotope journal
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• v.21 no.4
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• pp.33-37
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• 2006

A fertilizer mixed with an electron beam irradiated sewage sludge and a starfish powder was developed. By the irradiation of sewage sledge, it could be hygienic from harmful microorganism and be free from Rely nucleonic Aromatic Hydrocarbons (PAHs). The quality of fertilizer mainly consisted of electron beam irradiated sewage sledge could be enhanced by addition of starfish powder rich in organic calcium ion. The growth rate for a grass and a rose tree was enhanced about 35% when a fertilizer applied. By the development of new type of fertilizer, a large amount of sewage sledge and star fish con be utilized as a fertilizer.