• Title/Summary/Keyword: 미량 화학

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Quantitative Elemental Analysis in Soils by using Laser Induced Breakdown Spectroscopy(LIBS) (레이저유도붕괴분광법을 활용한 토양의 정량분석)

  • Zhang, Yong-Seon;Lee, Gye-Jun;Lee, Jeong-Tae;Hwang, Seon-Woong;Jin, Yong-Ik;Park, Chan-Won;Moon, Yong-Hee
    • Korean Journal of Soil Science and Fertilizer
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    • v.42 no.5
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    • pp.399-407
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    • 2009
  • Laser induced breakdown spectroscopy(LIBS) is an simple analysis method for directly quantifying many kinds of soil micro-elements on site using a small size of laser without pre-treatment at any property of materials(solid, liquid and gas). The purpose of this study were to find an optimum condition of the LIBS measurement including wavelengths for quantifying soil elements, to relate spectral properties to the concentration of soil elements using LIBS as a simultaneous un-breakdown quantitative analysis technology, which can be applied for the safety assessment of agricultural products and precision agriculture, and to compare the results with a standardized chemical analysis method. Soil samples classified as fine-silty, mixed, thermic Typic Hapludalf(Memphis series) from grassland and uplands in Tennessee, USA were collected, crushed, and prepared for further analysis or LIBS measurement. The samples were measured using LIBS ranged from 200 to 600 nm(0.03 nm interval) with a Nd:YAG laser at 532 nm, with a beam energy of 25 mJ per pulse, a pulse width of 5 ns, and a repetition rate of 10 Hz. The optimum wavelength(${\lambda}nm$) of LIBS for estimating soil and plant elements were 308.2 nm for Al, 428.3 nm for Ca, 247.8 nm for T-C, 438.3 nm for Fe, 766.5 nm for K, 85.2 nm for Mg, 330.2 nm for Na, 213.6 nm for P, 180.7 nm for S, 288.2 nm for Si, and 351.9 nm for Ti, respectively. Coefficients of determination($r^2$) of calibration curve using standard reference soil samples for each element from LIBS measurement were ranged from 0.863 to 0.977. In comparison with ICP-AES(Inductively coupled plasma atomic emission spectroscopy) measurement, measurement error in terms of relative standard error were calculated. Silicon dioxide(SiO2) concentration estimated from two methods showed good agreement with -3.5% of relative standard error. The relative standard errors for the other elements were high. It implies that the prediction accuracy is low which might be caused by matrix effect such as particle size and constituent of soils. It is necessary to enhance the measurement and prediction accuracy of LIBS by improving pretreatment process, standard reference soil samples, and measurement method for a reliable quantification method.

Effects of Temperature and Saturation on the Crystal Morphology of Aragonite (CaCO3) and the Distribution Coefficient of Strontium: Study on the Properties of Strontium Incorporation into Aragonite with respect to the Crystal Growth Rate (온도와 포화도가 아라고나이트(CaCO3)의 결정형상과 스트론튬(Sr)의 분배계수에 미치는 영향: 결정성장속도에 따른 아라고나이트 내 스트론튬 병합 특성 고찰)

  • Lee, Seon Yong;Chang, Bongsu;Kang, Sue A;Seo, Jieun;Lee, Young Jae
    • Korean Journal of Mineralogy and Petrology
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    • v.34 no.2
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    • pp.133-146
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    • 2021
  • Aragonite is one of common polymorphs of calcium carbonate (CaCO3) and formed via biological or physical processes through precipitation in many different environments including marine ecosystems. It is noted that aragonite formation and growth as well as the substitution of trace elements such as strontium (Sr) in the aragonite structure would be dependant on several key parameters such as concentrations of chemical species and temperature. In this study, properties of the incorporation of Sr into aragonite were investigated over a wide range of various saturation conditions and temperatures similar to the marine ecosystem. All pure aragonite samples were inorganically synthesized through a constant-addition method with varying concentrations of the reactive species ([Ca]=[CO3] 0.01-1 M), injection rates of the reaction solution (0.085-17 mL/min), and solution temperatures (5-40 ℃). Pure aragonite was also formed even under the Sr incorporation conditions (0.02-0.5 M, 15-40 ℃). When temperature and saturation index (SI) with respect to aragonite increased, the crystallinity and the crystal size of aragonite increased indicating the growth of aragonite crystal. However, it was difficult to interpret the crystal growth rate because the crystal growth rate calculated using BET-specific surface area was significantly influenced by the crystal morphology. The distribution coefficient of Sr (KSr) into aragonite decreased from 2.37 to 1.57 with increasing concentrations of species (Ca2+ and CO32-) at a range of 0.02-0.5 M. Similarly, it was also found that KSr decreased 1.90 to 1.54 at a range of 15-40 ℃. All KSr values are greater than 1, and the inverse correlation between the KSr and the crystal growth rate indicate that Sr incorporation into aragonite is in a compatible relationship.

The Hydrochemistry of ChusanYongchulso Spring, Cheonbu-ri, Buk-myeon, Northern Ulleung Island (울릉도 북면 천부리 추산 용출소의 수질화학적 특성)

  • Lee, Byeong Dae;Cho, Byong Wook;Choo, Chang Oh
    • The Journal of Engineering Geology
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    • v.28 no.4
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    • pp.565-582
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    • 2018
  • We investigated the hydrochemical properties of ChusanYongchulso Spring located in Buk-myeon, Ulleung Island, focusing on the formation and characteristics of aquifers in and around the Nari caldera. Abundant pumice with high permeability and numerous fractures (including faults and joints) that formed as a result of caldera subsidence are widely distributed in the subsurface, favoring the formation of aquifers. Because of the presence of porous pyroclastic rocks with a high internal surface area, the water type of the springs is characterized by $NaHCO_3$, with upper stream waters and the upper spring being characterized by $NaHCO_3$ and NaCl, respectively. Components with a high coefficient of determination with EC are $HCO_3$, Na, F, Ca, Mg, Cl, $SiO_2$, and $SO_4$. The high concentrations of Na and Cl might be attributable to the main lithologies in the area, given that alkaline volcanic rocks are distributed extensively across Ulleung Island. Eh and pH, which are considered to be important indicators of water-rock interaction, are unrelated to most components. According to the results obtained from factor analysis, the variance explained by factor 1 is 54% and by factor 2 is 25.8%. Components with a high loading on factor 1 are F, Na, EC, Cl, $HCO_3$, $SO_4$, $SiO_2$, Ca, $NO_3$, and Mg, whereas components with a high loading on factor 2 are Mg and Ca, along with K, $NO_3$, and DO with negative loadings. It is suggested that the high concentrations of Na, Cl, F, and $SO_4$ are closely related to the presence of fine-grained alkaline pyroclastic rocks with high permeability and porosity, which favorintensewater-rock interaction. However, a wide-ranging investigation that encompasses methods such as geophysical prospecting and geochemical analysis (including isotope, trace-element, and tracer techniques) will be necessary to gain a better understanding of the groundwater chemistry, aquifer distribution, and water cycling of Ulleung Island.

Characterization of CaCO3 Formation Using an Ion Selective Electrode : Effects of the Mg/Ca Ratio and Temperature (이온 선택성 전극을 이용한 탄산칼슘 형성 특성 연구 : 마그네슘-칼슘 비율과 반응 온도의 영향)

  • Misong Han;Byoung-Young Choi;Seung-Woo, Lee;Jinyoung Park;Soochun Chae;Jun-Hwan Bang;Kyungsun Song
    • Applied Chemistry for Engineering
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    • v.34 no.2
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    • pp.111-120
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    • 2023
  • The nucleation mechanism was studied using a calcium ion selective electrode (Ca ISE) to observe the formation of CaCO3, a representative mineral in the CO2 cycle, and to analyze the effect of the Mg/Ca-ratio and temperature on the formation of pre-nucleation cluster (PNC) and CaCO3. As a result of the experiment, a small amount of crystal was formed. Energy dispersive X-ray spectroscopy (EDS) was used for surface element analysis, and a field emission scanning-electron microscope (FE-SEM) was used for the morphology analysis of synthesized carbonates. These results showed that various shapes of crystalline CaCO3 (calcite, aragonite, etc.) were observed for each Mg/Ca ratio and temperature. In addition, the calibration plot obtained from Ca ISE showed information on the formation process of CaCO3. Our results showed that as magnesium ions interfered with the binding of calcium and carbonate ions and delayed the aggregation between PNCs, the nucleation and formation of CaCO3 were delayed. On the other hand, the temperature showed an opposite trend as compared to the effect of magnesium under our experimental conditions, indicating that temperature accelerated the formation of CaCO3. Furthermore, the morphology of CaCO3 clearly changed according to the Mg/Ca ratio and temperature, and it was confirmed that the two factors are very important for CaCO3 formation in that they could affect the overall process.

Soil properties in Panax ginseng nursury by parent rock (모암별 인삼묘포지의 토양특성에 관한 연구)

  • Min, Ell-Sik;Park, Gwan-Soo;Song, Suck-Hwan;Lee, Sam-Woong
    • Korean Journal of Agricultural Science
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    • v.30 no.1
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    • pp.31-40
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    • 2003
  • A research has been done for growing characteristics of Korean ginseng in Geumsan of Chungnam Province. It had been made to determine the transitional element concentrations of the rocks, divided by biotitic granite(GR) and phyllite(PH). The physical and chemical properties of their weathering soils and ginseng nursery soils were analyzed. The texture in the GR weathering and ginseng nursery soils were sandy clay, and the texture of the PH weathering and ginseng nursery soils were heavy or silty clay. The bulk densities of the GR and PH weathering soils were $1.21{\sim}1.32g/cm^3$ and $1.26{\sim}1.38g/cm^3$, respectively. Also, the bulk densities of the GR and PH ginseng nursery soils were $1.02{\sim}1.10g/cm^3$, respectively. The pH (4.80) of the GR weathering soil were lower than the pH of the PH(5.34) weathering soil. The pH in the 2 year and 4 year-ginseng nursery soil of the GR were 4.39 and 4.40. In addition, those of the PH were 5.24 and 5.34, respectively. The difference in pH of the two nursery soils could be from the pH difference between the two parent materials. The organic matter contents of the GR weathering soils(0.24%) were higher than those of the PH(1.02%) weathering soils. The organic matter of the 2 and 4 year-ginseng GR nursery soils were 0.87% and 1.52%, and of the PH nursery soils were 2.06% and 2.96%, respectively. The total nitrogen contents of the GR weathering soils were 259.43ppm and of the PH weathering soils were 657.22ppm. Those of 2 and 4 year-ginseng GR nursery soils were 588.04ppm and 657.22ppm and those of the PH nursery soils were 1037.72ppm and 1227.96ppm, respectively. The nitrate and ammonium contents of the GR weathering soils were the extremely small, and those of the PH weathering soils were 6.7ppm and 9.94ppm. Those of 2 year-ginseng GR nursery soils(223.09ppm and 26.96ppm) were higher than those of PH(19.46ppm and 8.23ppm) nursery soils. And those of 2 year-ginseng PH nursery soils(14.22ppm and 16.84ppm) were lower than those of PH(306.93ppm, 34.21ppm) nursery soils. The difference was due to fertilizer types and more deposits of nitrate after oxidation of ammonium. The phosphate contents of the GR and PH weathering soils were 14.41ppm and 38.60ppm. Those of GR 2 and 4 year-ginseng nursery soils were 46.89ppm and 102.44ppm and those of the PH nursery soils were 147.04ppm and 38.60ppm. The cation exchange capacities of the GR weathering soils were 12.34me/100g and those of the PH weathering soils were 15.40me/100g. Those of 2 and 4 year-ginseng GR nursery soils were 15.80me/100g and 7.70me/100g and those of PH nursery soils were 12.14me/100g and 12.83me/100g. All of exchangeable cation($K^+$, $Ca^{2+}$, $Mg^{2+}$, $Na^+$) contents in the nursery soils were higher than those in the weathering soils. The $SO_4{^2-}$ contents of the weathering soils in both of the GR(5.98ppm) and PH(9.94ppm) were higher than those of the GR and PH ginseng nursery soils. The $Cl^-$) contents of the GR and PH weathering soils were a very small and those of the nursery soils(2-yr GR: 39.06ppm, 4-yr GR: 273.43ppm, 2-yr PH: 66.41ppm, 4-yr PH: 406.24ppm) were high because of fertilizer inputs.

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Occurrence and Chemical Composition of Ti-bearing Minerals from Samgwang Au-ag Deposit, Republic of Korea (삼광 금-은 광상에서 산출되는 함 티타늄 광물들의 산상 및 화학조성)

  • Yoo, Bong Chul
    • Korean Journal of Mineralogy and Petrology
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    • v.33 no.3
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    • pp.195-214
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    • 2020
  • The Samgwang Au-Ag deposit has been one of the largest deposits in Korea. The deposit consists of eight lens-shaped quartz veins which filled fractures along fault zones in Precambrian metasedimentary rock, which feature suggest that it is an orogenic-type deposit. The Ti-bearing minerals occur in wallrock (titanite, ilmenite and rutile) and laminated quartz vein (rutile). They occur minerals including biotite, muscovite, chlorite, white mica, monazite, zircon, apatite in wallrock and white mica, chlorite, arsenopyrite in laminated quartz vein. Chemical composition of titanite has maximum vaules of 3.94 wt.% (Al2O3), 0.49 wt.% (FeO), 0.52 wt.% (Nb2O5), 0.46 wt.% (Y2O3) and 0.43 wt.% (V2O5). Titanite with 0.06~0.14 (Fe/Al ratio) and 0.06~0.15 (XAl (=Al/Al+Fe3++Ti)) corresponds with metamorphic origin and low-Al variety. Chemical composition of ilmenite has maximum values of 0.07 wt.% (ZrO2), 0.12 wt.% (HfO2), 0.26 wt.% (Nb2O5), 0.04 wt.% (Sb2O5), 0.13 wt.% (Ta2O5), 2.62 wt.% (As2O5), 0.29 wt.% (V2O5), 0.12 wt.% (Al2O3) and 1.59 wt.% (ZnO). Chemical composition of rutile in wallrock and laminated quartz vein has maximum values of 0.35 wt.%, 0.65 wt.% (HfO2), 2.52 wt.%, 0.19 wt.% (WO3), 1.28 wt.%, 1.71 wt.% (Nb2O3), 0.03 wt.%, 0.07 wt.% (Sb2O3), 0.28 wt.%, 0.21 wt.% (As2O5), 0.68 wt.%, 0.70 wt.% (V2O3), 0.48 wt.%, 0.59 wt.% (Cr2O3), 0.70 wt.%, 1.90 wt.% (Al2O3) and 4.76 wt.%, 3.17 wt.% (FeO), respectively. Rutile in laminated quartz vein is higher contents (HfO2, Nb2O3, As2O5, Cr2O3, Al2O3 and FeO) and lower content (WO3) than rutile in wallrock. The substitutions of rutile in wallrock and laminated quatz vein are as followed : rutile in wallrock [(Fe3+, Al3+, Cr3+) + Hf4+ + (W5+, As5+, Nb5+) ⟵⟶ 2Ti4+ + V4+, 2Fe2+ + (Al3+, Cr3+) + Hf4+ + (W5+, As5+, Nb5+) ⟵⟶ 2Ti4+ + 2V4+], rutile in laminated quartz vein [(Fe3+, Al3+) + As5+ ⟵⟶ Ti4+ + V4+, (Fe3+, Al3+) + As5+ ⟵⟶ Ti4+ + Hf4+, 4(Fe3+, Al3+) ⟵⟶ Ti4+ + (W5+, Nb5+) + Cr3+], respectively. Based on these data, titanite, ilmenite and rutile in wallrock were formed by resolution and reconcentration of cations (W5+, Nb5+, As5+, Hf4+, V4+, Cr3+, Al3+, Fe3+, Fe2+) in minerals of wallrock during regional metamorphism. And then rutile in laminated quartz vein was formed by reconcentration of cations (Nb5+, As5+, Hf4+, Cr3+, Al3+, Fe3+, Fe2+) in alteration minerals (white mica, chlorite) and Ti-bearing minerals reaction between hydrothermal fluid originated during ductile shear and Ti-bearing minerals (titanite, ilmenite and rutile) in wallrock.

Agronomical studies on the major environmental factors of rice culture in Korea (수도재배의 주요환경요인에 관한 해석적 조사연구)

  • Yung-Sup Kim
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.3
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    • pp.49-82
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    • 1965
  • For the stable and high yields of low-land rice in Korea, the characteristics of rice plant for the vegetative and physiological responses, plant type formation, and yield components have been studied in order to obtain the fundamental data for the improvement of cultural practices, especially for the ideal fertilizer application. Furthermore the environmental conditions in Korea including temperatures, light, precipitation, and soil conditions have been compared in the broad sense with those in Japan, and the application of nitrogen, phosphorus, potassium, silicate and other micro-nutrients were described in relation to the characteristics of environmental conditions for the improvement of fertilizer application. 1. The average yield of polished-rice per 10 are in Korea is about 204 kg and this values are much less than those in Japan and Taiwan where they produce 77% to 13% more than in Korea. The rate of yield increase a year in Korea is 4.2 kg, but in Japan and Taiwan the rates of yield increase a year are 81 % and 62%, respectively. It was also found that the coefficient of variation of yield is 7.7% in Korea, 6.7% in Japan and 2.5% in Taiwan. This means that the stability of producing rice in Korea is very low when compared with those in Japan and Taiwan. 2. It was learned from the results obtained from the 'annual yield estimation experiment' that there are big differences in the respect of plant type formations between rice crops grown in Japan and Korea. The important differences found were as follows: (1) The numbers of spikelets per 3.3 square meters are 891 in Korea and 1, 007 in Japan(13% more than in Korea). (2) The numbers of tillers per 3.3 square meters at the stage of maximum tillering are 1, 150 in Korea, but in Japan they showed 19% more than in Korea. (3) The ratio of effective tillers to total tillers is 77.5% in Korea and 74.7% in Japan, which seems to be higher in Korea than in Japan. But the ratio in Korea is very low when considered the numbers of total tillers in both countries. (4) The ratio of grain to straw is 85.4% in Korea and 96.3% in Japan. 3. The average temperatures during the growing season at the area of Suwon, Kwangjoo and Taegu are almost same as those in the district of Jookokoo(Fookoo yama) in Japan, i.e., the temperatures during the rice-growing season in Korea are similar to those in the southern-warm regions of Japan. 4. Considering the minimum temperatures at the stage of limiting transplanting, 13$^{\circ}C$, the time of transplanting might be 30 to 40 days earlier than presently practicing transplanting time, which comes around June 10. 5. The temperatures during the vegetative growth in Korea were higher than those temperatures that needed in the protein synthesis which ate the main metabolism during this stage. However, the temperatures at the time of reproductive growth was lower than the temperatures that needed in the sugar assimilation which is main metabolism in this stage. In this point of view, it might be considered that the proper time of growing rice plant in Korea would be rather earlier. 6. The temperatures and the day light conditions at the time of first tillering stage of rice plant, when planted as presenting transplanting practices, are very satisfactory, but the poor day light length, high temperatures and too wet conditions in the time of last-tillering stage(mid or last July) might cause the occurrence of disease such as blast. 7. The heading stage of rice plants at each region through nations when planted as presently practicing method comes when the day light length is short. 8. It was shown that the accumulated average air-temperature at the time of maturing stage was not enough and the heading time was too late, when considered the annual deviations of mean temperatures and low minimum temperatures. 9. The nitrogen content of each plant part at the each growing stage was very high at the stage of vegetative growth when compared with the nitrogen content at the stage of reproductive growth after heading. In this respect it was believed to be important to prevent the nutrient shortages at the reproductive stages, especially after the heading. 10. The area of unsatisfactory irrigation paddy fields and natural rain-fed paddy fields are getting reduced in Korea. The correlation between the rate of reducing unsatisfactory irrigation and natural rain-fed paddy fields and the rate of yield increase were computed. The correlation coefficients(r) between the area of unsatisfactory irrigation paddy fields and yield increase were +0.525, and between the natural rain-fed paddy fields and yield increase, +0.832 and between the unsatisfactory irrigation plus natural rain-fed paddy fields and yield increase, +0.84. And there were. highly significant positive correlations between natural rain-fed paddy fields and yield increases indicating that the less the area of natural rain-fed paddy fields, the greater the yields per unit area. 11. The results obtained from the fertilizer experiments (yield performance trials) conducted in both Korea and Japan showed that the yield of non-fertilized plots per 10 are was 231 kg in Korea and 360 kg in Japan. On the basis of this it might be concluded that the fertility of soil in Korea is lower than that in Japan. Furthermore it was. also found that the yields of non-nitrogen applied plots per 10 are were 236 kg in Korea and 383 kg in Japan. This also indicates that the yields of rice in Korea are largely depending on the nitrogen content in the soil. 12. The followings were obtained when the chemical natures of soils in both Korea and Japan were compared. (1) The content of organic matter, total nitrogen, exchangeable calcium, and magnesium in Korea were no more than the half those in Japan. (2) The content of N/2 chloride and soluble silicate in low-land soil were on the average lower in Korea. (3) The exchange capacity of bases in Korea was no more than half that in Japan. 13. It was also observed by comparing the soil nature of the soil with high yielding capacity with the soil with low yielding capacity that the exchange capacity of bases, exchangeable calcium and magnesium, potassium, phosphorus, manganese, silicate and iron were low in the soil with low yielding capacity. 14. The depth of furrow slice was always deeper in the soil with high yielding capacity, and the depth of furrow slice in Korea was also shallower than that in Japan. 15. Summarizing the various conditions mentioned previously and considering the effects of silicate and trace elements such as manganese and iron besides three elements on the physiological and plant type formation of rice crops, more realistic and more ideal fertilizing practices were proposed. proposed.

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Studies on the physio-chemical properties and the cultivation of oyster mushroom(Pleurotus ostreatus) (느타리버섯의 생리화학적성질(生理化學的性質) 및 재배(栽培)에 관(關)한 연구(硏究))

  • Hong, Jai-Sik
    • Applied Biological Chemistry
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    • v.21 no.3
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    • pp.150-184
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    • 1978
  • Nutritional characteristics and physio-chemical properties of mycelial growth and fruitbody formation of oyster mushroom(Pleurotus ostreatus)in synthetic media, the curtural condition for the commerical production in the rice straw and poplar sawdust media, and the changes of the chemical components of the media and mushroom during the cultivation were investigated. The results can be summarized as follows: 1. Among the carbon sources mannitol and sucrose gave rapid mycelial growth and rapid formation of fruit-body with higher yield, while lactose and rhamnose gave no mycelial growth. Also, citric acid, succinic acid, ethyl alcohol and glycerol gave poor fruit-body formation, and acetic acid, formic acid, fumaric acid, n-butyl alcohol, n-propyl alcohol and iso-butyl alcohol inhibited mycelial growth. 2. Among the nitrogen sources peptone gave rapid mycelial growth and rapid formation of fruit-body with higher yield, while D,L-alanine, asparatic acid, glycine and serine gave very poor fruit-body formation, and nitrite nitrogens, L-tryptophan and L-tyrosine inhibited mycelial growth. Inorganic nitrogens and amino acids added to peptone were effective for fruit-body growth, and thus addition of ammonium sulfate, ammonium tartarate, D,L-alanine and L-leucine resulted in about 10% increase fruit-body yield. L-asparic acid about 15%, L-arginine about 20%, L-glutamic acid, and L-lysine about 25%. 3. At C/N ratio of 15.23 fruit-body formation was fast, but the yield decreased, and at C/N ratio of 11.42 fruit-body formation was slow, but the yield increased. Also, at the same C/N ratio the higher the concentration of mannitol and petone, the higher yield was produced. Thus, from the view point of both yield of fruit-body and time required for fruiting the optimum C/N ratio would be 30. 46. 4. Thiamine, potassium dihydrogen phosphate and magnecium sulfate at the concentration of $50{\mu}g%$. 0.2% and 0.02-0.03%, respectively, gave excellent mycelial and fruit-body growth. Among the micronutrients ferrous sulfate, zinc sulfate and manganese sulfate showed synergetic growth promoting effect but lack of manganese resulted in a little reduction in mycelial and fruit-body growth. The optimum concentrati on of each these nutrients was 0.02mg%. 5. Cytosine and indole acetic acid at 0.2-1mg% and 0.01mg%, respectively, increased amount of mycelia, but had no effect on yield of fruit-body. The other purine and pyrimidine bases and plant hormones also had no effect on mycelial and fruit-belly yield. 6. Illumination inhibited mycelial growth, but illumination during the latter part of vegetative growth induced primordia formation. The optimum light intensity and exposure time was 100 to 500 lux and 6-12 hours per day, respectively. Higher intensity of light was injurous, and in darkness only vegetative growth without primordia formation was continued. 7. The optimum temperature for mycelial growth was $25^{\circ}C$ and for fruit-body formation 10 to $15^{\circi}C$. The optimum pH range was from 5.0 to 6.5. The most excellent fry it-body formation were produced from the mycelium grown for 7 to 10 days. The lesser the volume of media, the more rapid the formation of fruit-body; and the lower the yield of fruit-body; and the more the volume of media, the slower the formation of fruit-body, and the higher the yield of fruit-body. The primordia formation was inhibited by $CO_2$. 8. The optimum moisture content for mycelial growth was over 70% in the bottle media of rice straw and poplar sawdust. 10% addition of rice bran to the media exhibited excellent mycelial growth and fruit-body formation, and the addition of calciumcarbonate alone was effective, but the addition of calcium carbonate was ineffective in the presence of rice bran. 9. In the cultivation experiments the total yield of mushroom from the rice straw media was $14.99kg/m^2$, and from the sawdust media $6.52kg/m^2$, 90% of which was produced from the first and second cropping period. The total yield from the rice straw media was about 2.3 times as high as that from the sawdust media. 10. Among the chemical components of the media little change was observed in the content of ash on the dry weight basis, and organic matter content decreased as the cultivation progressed. Moisture content, which was about 79% at the time of spawning, decreased a little during the period of mycelial propagation, after which no change was observed. 11. During the period from spawning to the fourth cropping about 16.7% of the dry matter, about 19.3% of organic matter, and about 40% of nitrogen were lost from the rice straw media; about 7.5% of dry mallet, about 7.6% of organic matter, and about 20% of nitrogen were lost from the sawdust media. For the production of 1kg of mushroom about 232g of organic matter and about 7.0g of nitrogen were consumed from the rice straw media; about 235g of organic matter and about 6.8g of nitrogen were consumed from the sawdust media, 1㎏ of mushroom from either of media contains 82.4 and 82.3g of organic matter and 5.6 and 5.4g of nitrogen, respectively. 12. Total nitrogen content of the two media decreased gradually as the cultivation progressed, and total loss of insoluble nitrogen was greater than that of soluble nitrogen. Content of amino nitrogen continued to increase up to the third cropping time, after which it decreased. 13. In the rice straw media 28.0 and 13.8% of the total pentosan and ${\alpha}$-cellulose, respectively, lost during the whole cultivation period was lost during the period of mycelial growth; in the sawdust media 24.1 and 11.9% of the total pentosan and ${\alpha}$-cellulose, respectively, was lost during the period of mycelial growth. Lignin content in the media began to decrease slightly from the second cropping time, while the content of reduced sugar, trehalose and mannitol continued to increase. C/N ratio of the rice straw media decreased from 33.2 at spawining to 30.0 at ending; that of the sawdust media decreased from 61.3 to 60.0. 14. In both media phosphorus, potassium, manganese and zinc decreased, at magnesium, calcium and copper showed irregular changes, and iron had a tendency to be increased. 15. Enzyme activities are much higher in the rice straw media than in the sawdust media. CMC saccharifying and liquefying activity gradually increased from after mycelial propagation to the second cropping, after which it decreased in both media. Xylanase activity rapidly and greatly increased during the second cropping period rather than the first period. At the start of the third cropping period the activity decreased rapidly in the rice straw media, which was not observed in the sawdust media. Protease activity was highest after mycelial propagation, after which it gradually decreased. The pH of the rice straw media decreased from 6.3 at spawning to 5.0 after fourth cropping; that of the sawdust media decreased from 5.7 to 4.9. 16. The contents of all the components except crude fibre of the mushroom from the rice straw media were higher than those from the sawdust media. Little change was observed in the content of the components of mushroom cropped from the first to the third period, but slight decrease was noticed at the fourth cropping.

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