• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.1
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• pp.42-47
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• 1990

Silage productivity of 7 corn and 3 sorghum hybrids was determined at two planting dates differing in rice black-streaked dwarf virus (RBSDV) infection rates in the southern part of Korea where RBSDV is prevalent. 1. Percent stand was similar between two planting dates, but that of corn hybrids (85.0-99.5 %) was higher compared with sorghum (59.8-82.3 %). Culm length of corn hybrids at April 23 planting was longer compared with May 20 planting, but that of sorghum hybrids was similar between two planting dates. 2. RBSDV infection rate of corn hybrids at April 23 planting was lower compared with May 20 planting, but sorghum was not infected at both planting dates. Among corn hybrids Suweon 19 was most severely infected, but Suweon 99 was least infected at both planting dates. 3. Percent ear bearing plants and earltotal dry matter (TDM) ratio of corn hybrids at April 23 planting was higher than those of May 20 planting. Among the corn hygrids percent ear beraring plants, ear/TDM ratio of Suweon 19 was lowest at both planting dates due to severe RBSDV infection. Ear/TDM ratio of sorghum hybrids was below 17.8 % due to sterility and partially bud damages. 4. Silage yield at April 23 planting was higher than that at May 20 planting and sorghum hybrids outyielded corn hybrids. Silage yield of Suweon 19 and Jinjuok was lowest due to severe RBSDV infection. 5. Crude protein was similar regardless planting dates, species, and varieties except the lowest P 931. Ether extract at April 23 planting was lower then that at May 20 and corn was lower compared with sorghum hybrids. Crude fiber and nitrogen free extracts(NFE) was similar between planting dates. Crude fiber of corn was lower, but NEF was higher compared with sorghum, but similar among hybrids in a species. 6. In vitro dry matter digestibility (IVDMD) at May 20 planting was higher than that of April 23 planting and corn was higher than sorghum hybrids. Digestible dry matter (DDM) of both corn and sorghum at April 23 planting was higher than that of May 20 planting. At April 23 planting DDM of all corn and sorghum hybrids was similar, but DDM of Suweon 19 and Jinjuok was lower than other corn and sorghum hybrids.

• Journal of Mushroom
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• v.3 no.4
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• pp.140-144
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• 2005

This study was conducted to verify the cause of suppression symptom in mycelial growth during summer and to be able to establish a countermeasure. Cultivation of Flammulina velutipes was experimented with varying elapsed time of 0, 3, 6, 9 hours after mixing the sawdust media and two kinds of water temperature (normal water, $24^{\circ}C$ and cold water, $6^{\circ}C$) for mixing sawdust media. There were trends of increased media temperature from $24^{\circ}C$ to $31^{\circ}C$ and decreased pH from 6.5 to 5.2~5.6 with varying elapsed time from mixing the media to sterilization. Bacterial density also increased with bacterial density in Medium $24^{\circ}C$ being 1.9~4.1 times higher than that in Medium 6. Growth of F. velutipes was delayed with dual culture of bacteria isolated from sawdust media. Total nitrogen content of sawdust media was lowered by elapsed time from mixing the media to sterilization. The use of normal water($24^{\circ}C$) delayed mushroom growth by 1~2 days compared with that of cold water($6^{\circ}C$). Furthermore, mycelial growth of F. velutipes in the bottle cultivation ceased 9 hours after mixing the media. Primordia formation of F. velutipes was delayed by 1~3 days by elapsed time after mixing sawdust media, while fruit-body yield decreased by 7~12% 6 hours after mixing the media. Fruit-body yield was more stabilized with the use of cold water($6^{\circ}C$) than with that of normal water($24^{\circ}C$). Results showed that it is effective to use cold water as low as $6^{\circ}C$ in mixing media for F. velutipes cultivation, especially during summer when environmental temperature is high, high pressure sterilization after bottling work can prevent bacterial propagation in the media and can stabilize media ingredient.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.2
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• pp.129-136
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• 1973

In order to study the effects of climatic factors on barley responses to NPK fertilizers, the responses under the conditions of cold, moisture and drought damages and in different temperature regions, Nothern, Central, and Southern, which were devided according to average temperature for growing season of barley (from Nov. to May) were investigated from the results of NPK experiments which were carried out from Nov., 1965 to May 1969. The relationships between occurrence rate of cold, moisture, and drought damages and average or average lowest temperature in winter (Dec., Jan., and Feb), and the amount of precipitation in spring (Mar., Apr,. and May) were also investigated. 1. The lower the average lowest temperature, the higher the occurrence rate of cold damage of barley. When affected by cold damage, barley responded more significantly to P and K fertilizers. 2. The more the amount of precipitation in spring, the more the moisture damage and the less the drought damage. Damage from both moisture and drought were the lowest at 280mm. Since the average precipitation in spring in Korea is 230mm, drought damage is always more problem in terms of occurrence of damage, but total yield reduction is greater by moisture damage. 3. When affected by moisture damage, barley responded more to P and K fertilizers. In case of drought damage, only response to K was recognizable. 4. The reductions of barley yield due to cold, moisture, and drought damages were in average 31 (29-33), 42, and 19(12-25)%, respectively. 5. Average barley responses to NPK fertilizers were 44(34-58), 19(5-38), and 9(1-34)%, respectively by percent responses with regard to maximum possible yields. 6. Responses to nitrogen increased as the sunshine hours increased. Under dry condition, the response increased as the precipitation increased. However if the amount of precipitation was excessive or too little, the response was dropped markedly. 7. The responses to P and K were higher in North than South to the same degree. As the average temperature for growing season of barley (from Nov. to May) increased by $1^{\circ}C$, the percent responses to both P and K increased by 4.3%.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.667-682
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• 2014

The effects of liquid pig manure (LM) on the yield and quality of rice as well as soil chemical properties were determined in the field of sandy loam soil under the different fertilizer management. Treatments consisted of 100%, 130% and 160% N application rates of liquid manure as calculated on the basis of the recommended rate of nitrogen (9 kg N/10a) for rice cultivation. Chemical fertilizer (CF) was used as control. Concentrations of T-N and T-P in paddy water were measured by 5-day intervals up to 20days after application. LM treatments significantly increased T-N concentrations in paddy water proportionally with increasing rates of LM (13.2 to 25.7 mg/L). Similarly Total-P content in paddy water was increased right after LM applications but was well below the quality standard of wastewater and manure. Plant height and tillers in 100% and 130% N LM treatments were lower than those in CF control. In the 160% LM treatment, however, plant height and numbers of tillers were higher than those in the CF control. Yields in 100% LM and 160% LM plots were decreased by 3 and 5%, respectively, as compared with 422 kg per 10a in the CF plot. Rice protein contents were similar between 100% LM and CF control (about 6.8%) but it was increased to 7.2% and 7.7% in 130% LM and 160% LM treatments, respectively. Toyo-taste value in the 100% LM treatment was higher than in CF control plot. The proportions of perfect grain of the brown rice were lower in 130% LM and 160% LM treatments than that in CF control. Soil organic matter content, heavy metal and exchangeable cations were highest in the 160% LM plot. Thus considering yield and quality of rice and heavy metals contents in soil, 130% N basal application of liquid manure can be recommended for rice cultivation in this experiment.

• Horticultural Science & Technology
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• v.31 no.1
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• pp.65-71
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• 2013

This research was conducted to evaluate the influence of $NO_3{^-}:NH_4{^+}$ ratios in fertilizer solution on the vegetative growth and fruit yield of hot pepper (Capsicum annuum L.) through pot cultivation. The Hoaglad's solution was modified to contain various $NO_3{^-}:NH_4{^+}$ ratios such as 100:0 (A), 73:37 (B), 50:50 (C), 27:73 (D), 0:100 (E), and no nitrogen (F). Plants were transplanted into root substrates and the modified solutions were applied as plant needed in plastic house. There were no statistical significances among the treatments from A through D in the fresh and dry weights, and number of leaves 31 days after transplanting, but elevation of $NH_4{^+}$ ratios in the solution decreased the fresh fruit weight 62 days after transplanting with statistical differences. In the results of inorganic element analysis based on the dry weight of fully expanded mature leaves, N and P contents as well as micro cations such as Fe, Mn, Zn, and Cu increased as $NH_4{^+}$ ratios were elevated 62 days after transplanting. However, those of macro cations such as K, Ca, and Mg resulted in decreasing tendency. The elevation of $NH_4{^+}$ ratios in fertilizer solution resulted in the increase of EC and total N concentrations ($NO_3{^-}+NH_4{^+}$), but this decreased the pH as well as Ca and Mg concentrations in soil solution 62 days after transplanting. The K concentration in soil solution was the highest in the treatments of C and followed by D, B, E, and A. The above results indicate that the proper $NO_3{^-}:NH_4{^+}$ ratio in the nutrient solution is 73:27 (B) or 100:0 (A) and the B solution is proper for the vegetative growth and that of A is proper for reproductive growth stage.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.3
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• pp.187-194
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• 1985

This field experiment was carried out to determine the effects of thirteen different fertilizer levels of nitrogen(N), phosphorus($P_2O_5$) and potassium($K_2O$) on the content of crude protein, crude fiber, mineral constituents of product and tree growth forest pasture with 40-50% shading. The experiment was arranged as a randomized block design and performed in the suburban forest of Suweon in 1984. The results obtained are summarized as follows: 1. Crude protein content and total protein yield were higher in the plot of 28 and 42kg $N/_{10a}$, regardless of $P_2O_5\;and\;K_2O$ level, while those were the lowest in zero fertilizer and N-zero fertilizer plots. 2. The contents of lignin and silica were significantly low in the high N fertilizer level, and the contents of NDF, ADF, cellulose and hemicellulose were not affected by different fertilizer levels. However, the content of crude fiber tended to be low with high N, regardless of $P_2O_5\;and\;K_2O$. 3. The contents of N,K and $SiO_2$ of grasses were influenced by different fertilizer levels. However, those of P,Ca,Ma and Na showed little differences. 4. The recovery percentage of NPK was higher in the plot of standard fertilizer level with 28-20-24 kg/10a, and higher recovery percentage was observed in $K_2O$, followed by N and $P_2O_5$ in that order. 5. The growth of tree was increased as the level of N fertilizer was increased, but no such trend was noted by $P_2O_5\;and\;K_2O$ levels. 6. Crude protein, crude fiber, some mineral contituents of grasses, and growth of tree were influenced by N level, regardless of $P_2O_5\;and\;K_2O$. And the optimum fertilizer level of $N-P_2O_5-K_2O$ seemed to be 28-20-24 kg/10a for the production of grasses with higher quality and more yield in the forest.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.1
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• pp.72-77
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• 1989

A study was conducted to obtain acid tolerant and superior Rhizobium meliloti strain for alfalfa on hilly acid soils. With host plant, eight isolates of R, meliloti selected in the vicinity of Milyang were evaluated for their ability to establish symbiotic effectiveness in acidified tube culture medium and vermiculite pot with different urea levels. Among isolates "YA03" was characterized for the ability to manifest to acid tolerance in three different soils of which pH were 5.0, 6.0, and 7.5. The results obtained were summarized as follows: 1. Of eight isolates "YA03" and "YA09" performed nodule in the tube medium of pH5.0, and in the symbiotic effectiveness YA03 was superior to others. 2. Alfalfa growth and $N_2-fixing$ activity by the inoculation of "YA03" isolate were better than others at the level of urea 1.25mM as well as nonurea. 3. Application of urea with inoculation of "YA03" islate to alfalfa was one of the effective factors for symbiotic effectiveness. 4. In infertile soil of pH5.0 inoculation of R. meliloti "YA03" to alfalfa caused the increase of shoot dry matter of 320% as compared to the control, and the total amount of yield was 131% as much yield in moderate fertile soil of pH7.5. Finally R. meliloti "YA03" isolate was selected as an acid tolerant strain.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.2
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• pp.108-117
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• 2005

Pharmaceutical byproduct sludge and cosmetic industry wastewater sludge can be used as a raw material of compost. Effects of three types of pharmaceutical byproduct sludge and one type of cosmetic industry wastewater sludge on soil properties and red pepper growth were investigated in a field based concrete pot ($2{\times}2m$). These sludges and pig manure ($5Mg\;ha^{-1}$, dry basis) were incorporated into the upper of loam soil 30 days prior to transplanting red pepper. Changes in soil properties and contents of heavy metals and toxic organic compounds in soil and plant were measured. And also plant growth measurement and bioassay of soil phytotoxicity were included. Contents of heavy metals were increased in the soils treated with the sludges. Plant growth in the sludge treatments were mostly inferior to that of NPK treatment, especially in early stage. Content of N in plant was lower in all sludge treatments at early and middle growth stages, and it was especially caused by characteristics and concentration of nitrogen and organic matter of sludges. Total yield of red pepper was highest in the NPK treatment and followed by pharmaceutical sludge 3, pig manure, pharmaceutical sludge 1, and pharmaceutical sludge 2, and the yield of cosmetic sludge treatment was considerably lower than others. HEM and PAHs contents in soil of cosmetic sludge treatment were $4.80mg\;kg^{-1}$ and $2,263.2{\mu}g\;kg^{-1}$, respectively. Root elongation of lettuce exposed to the water extract of soil treated with cosmetic sludge was about 20% of that found in the test with soil extract of non fertilization treatment. At present, raw materials of compost were authorized according to the contents of organic matter, heavy metals and product processing. Toxic organic compounds analysis and bioassay would be helpful for authorization and assessment of suitability of raw materials of compost.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.307-317
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• 2021

In recent years, global warming has led to frequent climate change-related problems, and elevated temperatures, among adverse climatic factors, represent a critical problem negatively affecting crop growth and yield. In this context, the present study examined the physiological traits of wheat plants grown under high temperatures. Specifically, the effects of elevated temperatures on seed development after heading were evaluated, and the vegetation indices of different organs were assessed using hyperspectral analysis. Among physiological traits, leaf greenness and OJIP parameters were higher in the high-temperature treatment than in the control treatment. Similarly, the leaf photosynthetic rate during seed development was higher in the high-temperature treatment than in the control treatment. Moreover, temperature by organ was higher in the high-temperature treatment than in the control treatment; consequently, the leaf transpiration rate and stomatal conductance were higher in the control treatment than in the high-temperature treatment. On all measuring dates, the weight of spikes and seeds corresponding to the sink organs was greater in the high-temperature treatment than in the control treatment. Additionally, the seed growth rate was higher in the high-temperature treatment than in the control treatment 14 days after heading, which may be attributed to the higher redistribution of photosynthates at the early stage of seed development in the former. In hyperspectral analysis, the vegetation indices related to leaf chlorophyll content and nitrogen state were higher in the high-temperature treatment than in the control treatment after heading. Our results suggest that elevated temperatures after the booting stage positively affect wheat growth and yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.297-306
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• 2021

To select rice (Oryza sativa L.) cultivars suitable for forage-rice double cropping system, the growth and grain quality of four early maturing rice cultivars (Joun, Jopyeong, Haedamssal, and Unkwang), and the chemical properties of soils were investigated under single- (fallow-rice) and forage-rice double-cropping systems in paddy fields in Miryang, southern Korea. The soil where two forage crops [Italian ryegrass (Lolium multiflorum Lam.) and oat (Avena sativa L.)] were cultivated during winter had a slightly lower pH; an increase in total nitrogen (T-N), K, Ca, and Na contents; and a slight decrease in organic matter and available P₂O₅ contents, compared with the soil fallowed during winter. This shows that the chemical properties of paddy soils can be improved by winter forage cropping. At the heading stage, the culm length, panicle length, panicle number, and leaf color of all cultivars, except for Haedamssal, were generally higher under double-cropping than under single-cropping. For Haedamssal, the culm length and leaf color did not differ between the cropping systems, but the panicle length was slightly shortened and its panicle number increased under double-cropping. After harvest, the yield of milled rice decreased for all cultivars except Haedamssal, but increased in Haedamssal under double-cropping. The head rice rate was slightly higher under double cropping, particularly in Jopyeong and Haedamssal, than under single-cropping. The protein content of milled rice under double cropping was higher and its amylose content was similar or slightly lower compared to those of rice under single cropping, resulting in decreased Toyo values for rice under double-cropping. The pasting temperature did not differ significantly between the cropping systems. However, Haedamssal had a low pasting temperature but a high Toyo value under double cropping, compared to the other three cultivars, suggesting that its palatability is relatively high. Furthermore, panicle number increased and milled rice yield did not decrease, even under double cropping. Therefore, Haedamssal seems to be the best cultivar for paddy-based double cropping with forage crops.