• Korean Journal of Soil Science and Fertilizer
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• v.34 no.4
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• pp.265-272
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• 2001

A manure compost has been identified as an alternative to fertilizer to increase soil fertility and crop production in farming fields. The aim of the present study was to evaluate the effects of pig manure compost on soil properties and rice productivity as well as to determine the optimum application rate. In 1997, a field experiment was carried out to evaluate the growth of rice on sandy loam, loam, and clay loam soils amended with 0, 5, 10, and $20Mg\;ha^{-1}$ of pig manure compost plus NPK, which decided by soil testing. Rice yields were higher in soils receiving manure compost amendment. The maxim um yields were evaluated with $7,520kg\;ha^{-1}$ in the levels of $4.2Mg\;ha^{-1}$ of pig manure compost application plus NPK in sandy loam, $7,320kg\;ha^{-1}$ in the levels of $10.7Mg\;ha^{-1}$ in loam, and $6,320kg\;ha^{-1}$ in $17.2Mg\;ha^{-1}$ in clay loam soil. The optimum application rate of pig manure compost, which decided for 95% of maximum yields, was $4.0Mg\;ha^{-1}$ in sandy loam and $7.0Mg\;ha^{-1}$ in loam and clay loam soils under the condition of chemical fertilization by soil diagnosis. An increase in rice yield indicated a better nutrient status in compost-amended soil which was supported by the higher nutrient contents of N, P and K in shoot of plants grown in soil with manure compost amendment. Addition of manure compost increased available phosphate, silicate and exchangeable K in the amended soils according to the rate of compost application rate. It can be concluded that the manure compost could be a suitable organic fertilizer for improving rice productivity and soil fertility, and an application rate of $4.0Mg\;ha^{-1}$ in sandy loam and $7.0Mg\;ha^{-1}$ in loam and clay loam soils would give the optimum rice yields in the standard fertilization by chemical fertilization.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.1
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• pp.88-100
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• 2018

Methane emissions from rice paddies are the largest source of greenhouse gases in the agricultural sector, but there are significant regional differences depending on the surrounding conditions and cultivation practices. To visualize these differences and to analyze their causes and characteristics, the methane emissions from each administrative district in South Korea were calculated according to the IPCC guidelines using the data from the 2010 Agriculture, Forestry and Fisheries Census, and then the results were mapped by using the ArcGIS. The nationwide average of methane emissions per unit area was $380{\pm}74kg\;CH_4\;ha^{-1}\;yr^{-1}$. The western region showed a trend toward higher values than the eastern region. One of the major causes resulting in such regional differences was the $SF_o$ (scaling factor associated with the application of organic matter), where the number of cultivation days played an important role to either offset or deepen the differences. Comparison of our results against the actual methane emissions data observed by eddy covariance flux measurement in the three KoFlux rice paddy sites in Gimje, Haenam and Cheorwon showed some differences but encouraging results with a difference of 10 % or less depending on the sites and years. Using the updated GWP (global warming potential) value of 28, the national total methane emission in 2010 was estimated to be $8,742,000tons\;CO_2eq$ - 13% lower than that of the National Greenhouse Gas Inventory Report (i.e., $10,048,000tons\;CO_2eq$). The administrative districts-based map of methane emissions developed in this study can help identify the regional differences, and the analysis of their key controlling factors will provide important scientific basis for the practical policy makings for methane mitigation.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.6
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• pp.439-446
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• 2009

Nitrogen balance in the regional scale which was calculated the difference between nitrogen input and output was estimated to assess the impact of rice cultivation on water environment. Nitrogen balances in Gyeonggi province, where nitrogen concentration in irrigation water was high and in Chungnam province, where nitrogen absorbtion by rice was high, were -5.4 and -8.3 kg $-8.3kg\;ha^{-1}\;yr^{-1}$, respectively. Nitrogen balances of paddy field in Gangwon province, where nitrogen output was small and irrigation water was clean, and in Gyeongnam province, where organic matter content of soil was high and rice yield was low, were 4.9 and $14.0kg\;ha^{-1}\;yr^{-1}$, respectively. Average nitrogen balance and total nitrogen absorption of paddy field in Korea were estimated to $-0.3kg\;ha^{-1}\;yr^{-1}$ and $-3,315Mg\;yr^{-1}$, respectively. When the nitrogen concentration in irrigation water was increased by $1mg \;L^{-1}$, nitrogen balance of rice paddy changed by $-2.91kg\;ha^{-1}\;yr^{-1}$. Also, when nitrogen fertilizer applied was decreased from 110 to $90kg\;ha^{-1}$ and the same harvest was maintained, the nitrogen absorption by rice paddy from irrigation water was estimated to increase by 10,600 Mg per year in Korea. However, in cases, the harvest was reduced to either 90% or 85%, nitrogen balances were changed from -11.7 to -2.3 and $2.4kg\;ha^{-1}$, respectively. These results suggest that the reduction of nitrogen fertilizer use may not always lead to a negative nitrogen balance and sustainable agriculture can achieve by not cutting down the use of fertilizer only but by reduction of fertilizer application concurrently by maintenance of harvest and by utilization of environmental characteristics such as nutrient contents in irrigation water and soils.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.738-743
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• 2012

Topographic conditions of agricultural fields work as a important factor to identify different soil properties. This study was conducted to investigate the selected soil chemical properties and the concentrations of heavy metals, Cd, Cr, Pb, Cu, Ni, and Zn, in the paddy fields of different topographic areas at four year intervals from 1999 to 2011. Three-hundred soil sampling sites in the paddy fields were selected from the different topographic areas that were local valley and fans, fluvio-marine deposits, alluvial plains, and diluvial terraces. The mean values of soil pH ranged 5.7~5.8 that were within optimal range for rice cultivation. The mean values of other properties such as soil organic matter (SOM) content, the concentrations of exchangeable cations, $K^+$, $Ca^{2+}$, and $Mg^{2+}$, and available silicate concentration were lower or close to the optimal values, but the mean concentrations of available phosphorus were exceeded the range of optimal value, $80{\sim}120mg\;kg^{-1}$, in many paddy fields. In particular, The concentrations of available phosphorus in the paddy fields of local valley and fans, alluvial plains, and fluvio-marine plains were mostly declined. However, in diluvial terrace areas, the phosphorus concentrations unexpectedly increased; furthermore, they were significantly higher than those in other topographic areas. The mean concentrations of 0.1 M HCl-extractable heavy metals, Cd, Cr, Pb, Cu, Ni, and Zn, in the paddy fields were slightly and gradually declined during the study years, but the Pb concentrations were not statistically changed. In addition, the concentrations of heavy metals were widely ranged depending on the different sampling sites. Nevertheless, the concentrations of heavy metals were significantly lower than the levels of Soil Contamination Warning Standard (SCWS) for agricultural lands (1-region) presented in Soil Environment Conservation Law (SECL).

• Journal of Mushroom
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• v.10 no.4
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• pp.236-243
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• 2012

Spent mushroom substrates is composted organic material remaining after a crop of mushroom is harvested. The raw materials of mushroom substrates are same feed ingredient as corncobs, rice brown, wheat brown, cotton seeds and beet pulp. During the mushroom cultivation process, the mushroom substrates was used 15-25% by mushroom and 75-85% of mushroom substrates was remained in the SMS. Among of the spent mushroom substrates, spent mushroom substrates of pleurotus eryngii, Pleurotus ostreatus and Flammuliua velutipes is can be use the energy feedstock of animal feed. The cellulose content of spent mushroom(pleurotus eryngii) substrates containing the sawdust was high and total digestible nutrients (TDN) values was low. The spent mushroom(pleurotus eryngii) substrates fermented with cellulase and xylanase producing bacteria is may be used as an ingredient of feed in TMR for Hanwoo steer.

• Journal of Korean Society of Forest Science
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• v.80 no.4
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• pp.436-444
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• 1991

To increase both the production of mushrooms and the usages of the residues (used media) for roughage, the pinchips(PC) and sawdusts(SD) of three Korean oak species were tested as cultivating media for Lentinus edodes with varing the composition of the media. The results are as follows. 1. Organic acids(tannic acid and citric acid), which were added in the PC medium to enrich the quality of mushrooms, did not increase the growths of the mycelia and the quality. 2. The mushrooms were able to be harvested from six months after beginning the cultivation. No significant differences were found among the qualities of the mushrooms produced by various treatments. 3. The contents of crude proteins(1.82-4.55%) in the used media were higher than those in woods (c.a. 0.7%), and the total digestible nutrients (44.0-46.0%) in the used medium were not much different from those in rice straws (c.a.48.0%). 4. The contents of some essential amino acids (methionine in the used medium of the tannic acid added PC or S.D. and isoleucine, phenylalanine and lysine in the used medium of the untreated PC or SD) were higher than those in the control (raw media). The contents of a few other essential amino acids (threonine, valine and arginine) were lower in the used media. Most nonessential amino acids in the used media, particularly in the used bed-log, appeared to decrease than those in the control.

• Research in Plant Disease
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• v.12 no.3
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• pp.158-163
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• 2006

Sclerotinia rot caused by Sclerotinia sclerotiorum frequently causes serious and unpredicable yield losses of the leaves of perilla growing under structured cultivation as vegetable in Korea. Temperature for mycelial growth ranged from 5 to $30^{\circ}C$ with optimum temperature d $20^{\circ}C$. Sclerotia were formed fewer at low temperature, but their dry weight was heavier than that at high temperature. The apothecia were formed from the sclerotia that buried up to 3 cm soil depth at $15^{\circ}C$ in moisture condition. The incidence of perilla Sclerotinia rot caused by S. sclerotiorum was observed throughout the growing season at greenhouse. The occurrence of this disease was especially severe from January to February of low temperature period. The average incidence rates of this disease was up to 15%. The significant occurrence of this disease was showed mainly in the continuous cropping field for more than five years. The incidence of this disease increased according to the increase of continuous cropping year. The incidence rates of this disease reached up to 20% in the continuous cropping field for ten years. Also it was firstly investigated the natural infection caused by S. sclerotiorum on weed plants, Gnaphalium affine and Mazus pumilus in farmer's field. The casual fungus showed pathogenicity on 11 weed plants species tested, and more severe pathogenicity on G. affine, Latuca indica and Ixeris dentata included in the family Compositae. This result suggests that effective crop rotation and weed eradication can be the method for organic control of perilla sclerotinia rot, and sudden outbreaks of this disease on perilla growing under structure after paddy rice call be explained by the presence of weed hosts.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.332-337
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• 2013

BACKGROUND: Newly reclaimed land has poor soil environment for crop growth since it is high in salt concentration but low in organic content compared with ordinary soil. It is known that whole-crop-barley can grow better in the soil of relatively high salt concentration than other crops but, the growth is poor at the concentration if higher than certain amount and it is a difficulty to secure productivity. Hence, the level of soil salt concentration suitable for the production of bulky feed in newly reclaimed land has been investigated. METHODS AND RESULTS: At Saemanguem reclaimed land, the land for the soil salt concentration electrical conductivity (EC) 0.8, 3.1, 6.5, 11.0 dS/m was selected; and chemical fertilizer $N-P_2O_5-K_2O$ (150-100-100kg/ha) was tested; and forage barley 220kg/ha were sown. The soil salt concentration during the cultivation period decreased in the order of harvest season>earing season>sowing season>wintering season, and the salt concentration in harvest season is 1.4-4.2 times higher than that of the sowing season. The higher the salt concentration, the poorer the over ground growth due to poor rooting; especially at EC 11.0 ds/m there was emergence but, it blighted after wintering. The Yield from the soil salt concentration 3.1dS/m and 6.5 dS/m was 68% and 35% from that of the soil salt concentration 0.8 dS/m (8.8 MT/ha) respectively. The proline content in early life stage was more than that of the harvest season, and it increased with salt concentration. The higher salt concentration, the more $Na_2O$ and MgO content in harvest season; but the higher the salt concentration, the less the content of N, $P_2O_5$, $K_2O$ and CaO. CONCLUSION(S): When the soil salt concentration becomes higher than 3.1 dS/m, the yield becomes poor because there is serious growth inhibition of forage barley both in root part and above aerial part that results in unbalanced absorption of nutrients. Therefore, it is recommended that the salt concentration should be lowered below 3.1 dS/m by underground drainage facilities or irrigating water for the stable production of whole-crop-barley.

• Applied Biological Chemistry
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• v.37 no.4
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• pp.277-286
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• 1994

The pot experiment using $^{15}N$ isotope dilution technique was carried out to calculate the balance of nitrogen of surface applied urea in the rice-soil system. The $^{15}N$ concentration was determined by stable isotope ratio mass spcetrometer (model: VG ISO-GAS MM622). In the pots with $^{15}N$ labeled urea application at the rates of 15 and 30 kg N/10a, the percentage of nitrogen derived from fertilizer (NDFF) in rice was higher at the rate of 30 kg N/10a (average 89%) than at the rate of 15 kg N/10a (average 64%). However, the recovery as percentage of fertilizer N by rice was higher at the rate of 15 kg N/10a (65.5%) than at the rate of 30 kg N/10a (54.2%). The percentage of the fertilizer N remained in extractable inorganic N form at the rates of 15 and 30 kg N/10a were $13.5%\;(NH_4-N\;5.53%,\;NO_3-N\;7.99%)$ and $16.5%\;(NH_4-N\;7.49%,\;NO_3-N\;8.98%)$ in unplanted soil, and $2.0%\;(NH_4-N\;0.63%,\;NO_3-N\;1.32%)$ and$2.3%\;(NH_4-N\;0.87%,\;NO_3-N\;1.40%)$ in soil planted to rice, respectively. The dominant form of inorganic-N in soil after harvest was $NO_3-N$ form rather than $NH_4-N$ form regardless of urea application rate or rice cultivation. The percentage of the fertilizer N remained in organic N form at the rates of 15 and 30 kg N/10a were 65.0 and 41.8% in unplanted soil, and 23.7 and 26.9% in soil planted to rice, respectively. In conclusion, the efficiency of surface-applied urea was greater at the rate 15 kg N/10a than at the rate of 30 kg N/10a.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.4
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• pp.403-408
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• 1987

The milled rice yield of the fertilized Zeolite in the sandy loam as 542 Kg/10a was increased by 11% compared with the check plat as a standard cultivation. Significant positive correlations of that were found between grain yield/plant and panicle/total weight ratio or average weight of panicle, while lower correlations between ratio of riqened grains and grain yield/ plant. But significant negative correlations were found between 1,000-grain weight of rough and 4th. 5th internode/culm length ratio. It was reavealed that there were higher direct effects for ratio of ripened grains and spikelets/panicle affecting grain yield/plant through path analysis among the yield components. Moreover, organic dry matter production at 35 days after heading were heavier by 26% in active leaves, 19% in stem + leaf sheath, and 5% in panicle, respectively. Ratio of settled spikelets on the terminal of primary rachis-branch was 47% to total spikelets, and 37% in half-upper of that, moreover many spikelets settled on the terminal of rachis. Therefore, it was recognized that there were a dominant effect of apical glumous flower by fertilized Zeolite.