• 한국환경농학회지
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• 제20권5호
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• pp.346-351
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• 2001

Oxidation of Cr(III) to Cr(VI) can increase availability and toxicity of chromium. In this study, possible mechanisms by which pH and organic matter can control the chromium oxidation and reduction in soil system were examined using four soils of different pHs and organic matter contents. Reduction of Mn-oxides occurred in the soils of higher organic matter content (4.0%), but Mn-oxide was quite stable during the incubation in the soil of pH 7.0 and 0.5% organic matter content. Manganese oxides can be reductively dissolved at lower pH and higher organic matter conditions. The soil of pH 7.0 and 4.0% organic matter content showed the highest Cr-oxidation potential. Reduction of soluble Cr(VI) was observed in all the soils examined. The most rapid reduction was found in soil of pH 5.5 and 4.0% organic matter content, but the reduction was slow in soil of pH 7.0 and 0.5% organic matter content. Thus, the reductive capacity of organic matter added soils was much higher as compared to other two soils of lower organic matter content. In all the soils examined, the reductive capacity of soluble chromium was much higher than the oxidative capacity. Organic matter was found to be the most important controlling factor in the chromium oxidation and reduction. Reduction of Cr(VI) to Cr(III) could be a potentially useful remediation or detoxification process, and availability and toxicity of chromium in soil would be controlled by controlling organic matter content and pH of the soils.

• 한국토양비료학회지
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• 제31권4호
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• pp.380-383
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• 1998

본 연구는 퇴비중의 유기물 함량으로부터 탄소함량을 구하기 위한 환산계수를 결정하기 위하여 수행하였다. 퇴비중의 유기물 함량은 회화법으로, 탄소함량은 원소 분석기를 사용하여 분석한 결과 유기물 함량과 탄소함량의 관계는 "탄소함량(%)=$1.995+0.484{\times}$유기물 함량(%)"의 직선 회귀식을 따랐고, 분산분석에 의한 회귀직선의 유의성 검정은 고도로 유의하게 나타났다(P < 0.001). 기존의 토양 유기물 환산계수 1.724나 1.8을 적용할 경우, 퇴비중의 유기물 함량으로부터 환산한 탄소함량은 실제보다 10% 이상 높게 평가되어 우리 나라에서 생산, 판매되는 퇴비의 탄소함량을 구할 때는 상기 회귀식을 적용하는 것이 타당하리라 생각된다.

• 한국토양비료학회지
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• 제45권1호
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• pp.30-36
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• 2012

The active fraction of soil organic matter, which includes organic debris and light organic fraction, plays a major role in nutrient cycling. In addition, particulate organic matter is a valuable index of labile soil organic matter and can reflect differences in various soil behaviors. Since soil organic matter bound to soil mineral particles has its density lower than soil minerals, we partitioned soil organic matter into debris ($<1.5g\;cm^{-3}$), light fraction ($1.5-2.0g\;cm^{-3}$), and heavy fraction ($>2.0g\;cm^{-3}$), based on high density $ZnCl_{2-}$ sucrose solutions. Generally, partitioned organic bands were clearly separated, demonstrating that the $ZnCl_{2-}$ sucrose solutions are useful for such a density gradient centrifugation. The available gradient ranges from 1.2 to $2.0g\;cm^{-3}$. Although there was not a statistically meaningful difference in organic debris and organomineral fractions among the examined soils, there was a general trend that a higher content of organic debris resulted in a higher proportion of light organomineral fraction. In addition, high clay content was associated with increased fraction of light organomineals. Partitioning of soil organic carbon revealed that carbon content is reduced in the heavy fraction than in the light fraction, reflecting that the light fraction contains more fresh and abundant carbon than the passive resistant fraction. It was also found that carbon contents in the overall organic matter, debris, light fraction, and heavy fractions may differ considerably in response to different farming practices.

• Journal of Biosystems Engineering
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• 제26권5호
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• pp.475-480
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• 2001

Sensing soil organic matter is crucial for precision farming and environment friendly agriculture. Near infra-red(NIR) was utilized to measure the soil organic matter. Multivariate calibration methods, including stepwise multiple linear regression(MLR), principal components recession(PCR) and partial least squares regression(PLS), were applied to soil spectral reflectance data to predict the organic matter content. The effect of soil particle size and water content was studied. The range of soil organic matter contents was from 0.5 to 11%. Near infrared (NIR) region from 700 to 2,500nm was applied. For uniform soil particle size, result had good correlation (R$\^$2/ = 0.984, standard error of prediction= 0.596). The effect of soil particle size could be eliminated with 1st order derivative of the NIR signal. However. moist soil had a little lower correlation. R$\^$2/ was 0.95 and standard error of prediction was 0.94% using the PLS method. The results showed the possibility of soil organic matter measurement using NIR reflectance on the field.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.223-223
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• 2017

This study aimed to determine the effect of organic matter content and water condition in soil on yield, carbohydrate, and inulin contents of two varieties of Jerusalem artichoke. The plants were grown with high and low organic soil either under irrigation or no irrigation in a randomized complete block design (RCBD) with three replications. In result, the yield of Jerusalem artichoke was higher about 7 kg in soil with high organic matter than in soil with low organic matter, while it was higher about 11 kg under the irrigation than under no irrigation. The yield of white variety was higher about 9 kg than that of purple variety. Under the irrigation, a 12 kg and 9 kg of higher yields were observed in the soil with high and low organic matter content, respectively, than under no irrigation.

• 아시안잔디학회지
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• 제4권1호
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• pp.24-30
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• 1990

This study was carried out to search for growth and quality -of turfgrass by Nitrogen source (Urea Ammonium sulphate) and organic matter, and to obtain methods of pr6per turfgrass management by the results. This experiment was conducted in turf field from 1988 to 1989. The results of this experiment was summarized as follows; 1.Without application of organic matter, turfgrass growth between urea and ammonium sulphate was not significant, however ammonium sulphate resulted in superior to urea in total dry weight when organic matter was applied. 2.The addition of organic matter showed significant effect on color rating and visible quality, and ammonium sulphate was higher quality than urea. 3.Shoot density increased, particularly in ammonium sulphate treatment, when organic matter was applied. 4.Rhizome and stolon were shown significant effect in urea treatment by the application of organic matter. 5.Surface soil pH was allowed to become slightly acid by the ammonium sulphate treatments, but soil acidity remained mostly unaffected when organic matter was supplied. 6.Total nitrogen of log tissue and organic matter content increased when organic matter w-as applied.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.57-59
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• 1998

The headspace method has been acknowledged as a cost-effective and convenient method to analyze volatile organic compounds(VOCs) in soil. The headspace analysis is based on equilibrium partitioning of VOCs among water, air and soil in a closed system. However, the headspace method cannot be applied to soils where most of the VOCs remain sorbed even at high temperature. In this study, it was investigated how the sorption characteristics of VOCs varied with soil with different organic carbon contents and temperature. This study showed that all the VOCs were volatilized, not sorved, only in the soil with 5% organic carbon at 45$^{\circ}C$ or higher. Some fraction of VOCs remained in soil with 8% organic carbon at $65^{\circ}C$ of higher. Most of the VOCs remained sorbed in soil with 12% organic content even at 95$^{\circ}C$. This result suggested that the headspace method can be applied only to soils with little organic carbon content (less than 5%). In this case, 45$^{\circ}C$ seems to be high enough to volatilize all the VOCs from soil. Large particles still showed a significant sorption capacity for VOCs from soil. Large Particles still showed a significant sorption capacity for VOCs despite of their low level of organic carbon content. It was also shown that the organic carbon sorption coefficients (Koc) of VOCs varied with soils with different organic carbon content. This suggests that not only the organic matter content of soil but also the property of the organic matter in soil influence the sorption of VOCs to soil.

• 농업과학연구
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• 제27권2호
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• pp.125-134
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• 2000

This observation was to investigate the influence of raw organic matter incorporated into soil at various rates on hydraulic conductivity and elution of solute throughout soil column. Generally the organic matter content in a practical agricultural field was approximately 3%. However, the application rate of organic matter in the field tends to rapidly increase in these days. Therefore, we raised the application rate of organic matter up to 10% in this investigation. From the experiment, we found that the hydraulic conductivities rapidly decreased with increasing rate of organic matter as well as rapid decrease in total volume of eluent during the same period. And electrical conductivities in the effluent significantly decreased after 2 pore volume, resulting in approaching to the criteria of saline soli. From this we could assume that the organic matter may influence the crop growth in the beginning. However excessive irrigation in the field may cause saturation of soil leading to reduction of soil. Therefore, there must be a management methods in application of organic matter with respect to soil water control.

• Environmental Engineering Research
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• 제18권4호
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• pp.259-265
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• 2013

This study was conducted June 2011 at Gamo Lagoon, after tsunami of March 2011, to estimate food sources and utilization. The results show that the tsunami affected the sediment properties by changing the physical environmental alterations. The fatty acids of the gut content of Nuttallia olivacea mostly comprised the same organic matter found in the sediment. Fatty acids in the tissues showed mainly diatoms, bacteria, and dinoflagellates. That is, most of the food sources (i.e., diatoms, bacteria, dinoflagellates, macroalgae, and terrestrial organic matter) probably pass through the digestive system unharmed; however, terrestrial organic matter, which is refractory to biochemical degradation, indicated a different assimilation trend between the gut content and the tissue. This result suggests that input of labile organic matter from the sediment may control selective metabolism in N. olivacea. From these results, although the physical environment of sediment characteristics by tsunami changed, the food utilization of N. olivacea suggested a better assimilation of selected components from the gut content, irrespective of physical alteration.

• 한국환경과학회지
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• 제8권5호
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• pp.587-592
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• 1999

The purpose of this study was to identify the controlling factors to construct tidal flat ecosystems having similar characteristics as natural ones. We transplanted the soil in a constructed tidal flat to a natural one and vice versa. Parameters monitored after these transplantations were silt content, organic matter, bacterial population and oxidation-reduction potential. Moreover, the relationship among silt content, organic matter and bacterial population was investigated by laboratory column experiment. The silt content, organic matter, bacterial population and vertical profile of oxidation-reduction potential in the soil transplanted from the constructed tidal flat to the natural one changed to similar values to those in the natural one. On the contrary, all the parameters for the soil transplanted from the natural tidal flat to the constructed one changed to similar values as those in the constructed one. The silt contents in thses two transplanted solis were in proportion to the organic carbon contents and bacterial population. Similarly, the bacterial population in laboratory column experiment increased with the increase in silt and organic matter contents. It seemed to be important to select a place to enhance accumulative of silt and/or to maintain the silt content by hydrodynamic control of seawater in order to construct a tidal flat having similar characteristics as natural one.