• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.260-265
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• 2012

Soil respiration under flooded conditions is considered to be very small compared with aerobic soil respiration of soil organic matter. However, anaerobic decomposition of soil plays a key role in carbon cycling in flooded ecosystems. On the other hand, coal-ash wastes, such as fly ash and bottom ash, are known to function as a soil amendment for mitigating $CO_2$ emission and enhancing carbon sequestration in up land soils. In this study, we investigated bottom ash as a soil amendment for mitigating $CO_2$ emission, and thus enhancing carbon sequestration under anaerobic conditions. We observed that amendment of bottom ash without external organic source led to significant reduction in $CO_2$ emission rate and in total cumulative $CO_2$ emission flux over the incubation period, which was proportional to the amount of bottom ash applied. We also found that soil microbial biomass increased in response to application of bottom ash. These results suggest that bottom ash can be utilized to store $CO_2$ as a stable soil organic carbon in flooded ecosystems, as in aerobic situations.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.1
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• pp.41-45
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• 1997

This study was conducted to investigate methane production, emission and diffusion under organic matter application in paddy soil (Jeonbug Series). The rates of application of rice straw were 5,000kg/ha in combination with 110kg N/ha as chemical fertilizer. In seasonal variations of the $CH_4$ emission rates two maxima were found during the ear formation stage and the heading stage of the rice plant. Entrapped methane increased dining the early growing season, declined thereafter and especially increased during the heading stage. Methane concentration in the soil solution was the higest at 5cm depth, but decreased with upper and lower depth. The gas diffusion rate of $CH_4$ was very slow in the liquid phase. Eh of soil solution varied from -150~-160mV and methane prodution rate was highly correlated with Eh.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.4
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• pp.330-336
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• 1984

These studies were aimed to find out the representative values of physico-chemical properties in Korean soils and to serve the basic informations to improve the soil properties for increasing the soil productivity. By the results of detailed soil survey, 14 physico-chemical properties (soil texture, moisture characteristics, organic matter content etc) were collected from 315 series of soils except Cheju soils, computerized the simple mean and the distributed area by weighted mean values with grouping of land use, drainage class and soil type. The results were as follows; 1. Simple mean values within the efficient soil depth in whole country soils were clay 20.0%, organic matter 2.03% and CEC 10.3me/100g. But weighted mean values with land area belonged to the same soil series were clay 18.0%, OM 1.85% and CEC 8.6me/100g. 2. Mean values of paddy soils weighted by area were clay 19.7%, OM 2.0% and CEC 9.1me/100g but those of upland soils were 17.9%, 1.8% and 8.1me/100g and forest soils were 16.7%, 1.8% and 8.6me/100g respectively. 3. Weighted mean values of moderately well soils with covered area were clay 18.9%, organic matter 1.7%, CEC 8.4me/100g but those of imperfectly drained soils were 21.3%, 2.2% and 9.5me/100g, and those of poorly drained soils were 15.1%, 1.8% and 9.9me/100g respectivcly. 4. Simple mean and area weighted mean values of clay content, pH, organic matter contents, cation exchange capacity and base saturation were calculated by the types of paddy and upland.

• Journal of Korean Society of Forest Science
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• v.79 no.4
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• pp.367-375
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• 1990

In order to determine the effects of bedrock, organic matter, calcium and iron oxide on the soil aggregation, this research has performed with soils from bedrock regions of Limestone, Granite and Granite gneiss. This research was also to estimate how organic matter, calcium and iron oxide influence on soil aggregation under different forest conditions in various bedrock regions. And it also had a purpose to rate physical factors relevant to soil aggregation, their characteristics and aggregate diameter which closely relates to stabilities in the process of soil erosion. The following conclusions have been drawn in response to the overall research objectives. The rates of the soil aggregation on different bedrock regions were 21% in Limestone bedrock, 19.8% in Granite bedrock and 9.9% in Granite gneiss bedrock. A main factor in soil aggregation was the orgainc matter content in soils and the rate of soil aggregation increased in the constant proportion with the organic matter content. The relation could be formulated into Y=4.31X-4.37(Y : aggregation ratio X : organic matter content). The soil aggregation ratio under the deciduous forests eras higher than that under the coniferous forests. It was considered that this resulted from differences in organic matter content. Soil aggregates with larger diameter than 0.5mm were found more in Limestone bedrock than other smaller size soil aggregates of 0.25mm diameter were more distributed in Granite gneiss bedrock. Granite bedrock region had normal distribution in soil aggregate sizes with the highest frequency of 0.5mm diameter. Calcium and iron oxides had only partial influences on the soil aggregation in some specific conditions. But in Limestone bedrock region calcium influenced on the soil aggregation with the organic matter content.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.968-974
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• 2010

We assessed the feasibility of discrete wavelet transform (DWT) applied for the spectral processing to enhance the estimation performance quality of soil organic matters using visible-near infrared spectra and mapped their distribution via block Kriging model. Continuum-removal and $1^{st}$ derivative transform as well as Haar and Daubechies DWT were used to enhance spectral variation in terms of soil organic matter contents and those spectra were put into the PLSR (Partial Least Squares Regression) model. Estimation results using raw reflectance and transformed spectra showed similar quality with $R^2$ > 0.6 and RPD> 1.5. These values mean the approximation prediction on soil organic matter contents. The poor performance of estimation using DWT spectra might be caused by coarser approximation of DWT which not enough to express spectral variation based on soil organic matter contents. The distribution maps of soil organic matter were drawn via a spatial information model, Kriging. Organic contents of soil samples made Gaussian distribution centered at around 20 g $kg^{-1}$ and the values in the map were distributed with similar patterns. The estimated organic matter contents had similar distribution to the measured values even though some parts of estimated value map showed slightly higher. If the estimation quality is improved more, estimation model and mapping using spectroscopy may be applied in global soil mapping, soil classification, and remote sensing data analysis as a rapid and cost-effective method.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.1
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• pp.10-16
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• 1991

Mean values and the relative contribution of OM and clay to total CEC for soil textural classes were obtained from the analytical results of the typical profiles(sample size : 3,182) which were described by the detailed soil maps througthout Korea with an exception of Jeju island. The results are below. 1. Mean values of the soil CEC were 2.9 for S, 4.7 for LS, 6.7 for SL, 9.0 for L, 10.2 for SiL, 10.7 for CL, 8.6 for SCL, 12.2 for SiCL, 16.1 for SiC, and 17.4me/100gr for C, respectively. 2. The multiple regression equation and partial regression coefficient tended to show that OM and clay had the highly significant effect on CEC. 3. Clay content of the coarse, moderately coarse, and moderately fine soil was 1.10 to 1.89 times as important as OM content whereas OM of the medium and fine soil 1.09 to 2.94 times as important as clay in predicting CEC. 4. Mean values of CEC of the humus and clay in Korean soils were about 62.9 and 24.0me/100gr, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.1
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• pp.20-27
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• 1983

A series of laboratory experiment was conducted to find out the chemical composition, characterization of humic substances by physical and chemical methods and reaction of Na-pyrophosphate, $Ca(OH)_2$ and rice straw with albumin on the degradation of soil organic matter in the volcanic ask soils of the Jeju Island. Results obtained were summarized as follows: 1. The contents of organic matter, available silicon, active iron and aluminum concentration in volcanic ash the soils were remarkably higher but available phosphorous was comparatively lower than the mineral soils. In volcanic ash soil, the contents of potassium, calcium and magnessium were higher in upland soil than that of forest soil. The ratios of active $Al^{{+}{+}{+}}/Fe^{{+}{+}}$, C/P and $K/Ca^+$ Mg were apparently high in volcanic ash soils while that of $SiO_2$/O.M. was high in mineral soil. 2. The carbon/nitrogen ratio in humin, humic acid content in organic matter, and carbon contents of humin in total carbon of soil organic matter were apparently higher in the volcanic ash soils than in the mineral soils, The total nitrogen and fractions of acid or alkali soluble nitrogen were remarkably high in volcanic ash soils while mineralizable nitrogen ($NH_4$-N and $NO_3$) contents were high in mineral soils. 3. The values of K600, RF and log K were also higher in volcanic ash soils than those in mineral soils, and the absorbance in the visible range were high and color was dark in the soil of which humification was progressed Extracted humic acid from volcanic ash soil was less reactive to the oxidizing chemical reagent and was persistance to the acid or alkali hydrolysises. 4. The major oxygen-containing functional groups in humic substances of volcanic ash soils were phenolic-OH alcoholic-OH and carboxyl groups while those in mineral soil were methoxyl and carbonyl groups. 5. Absorption spectra of alkaline solution of humic acid ranged from 200 nm to maxima 500 nm. Visible spectra peaks of from humic substances in the visible region were recognized at 350, 420, 450 and 480 nm. Only one single absorbance peak was observed in the visible region at 362 nm for Heugag series and two absorbance Peak were also at 360 nm and 390 nm for Yeungrag series. 6. Evolution of carbon as $Co_2$ was increased with addition of Na-pyrophosphate in Namweon and Heugag series, and "priming effects" took place on the soil organic matter decomposition by addition of rice straw with albumin in Ido series.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.3
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• pp.286-293
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• 1983

The glucose application remarkably increased the heterotrophic acetylene reducing activities during one month incubation. The amount of the increases varied between the soils. Application of rice straw brought about the significant increases during incubation time. Compost contained the largest amount of available-N among the C-sources, and thereby brought the smallest increase in all soils. The cumulative fixed nitrogen with application of rice straw at 30 days incubation in the three experimented soils were highest in Hwadong clay soil, i.e, $2.2mg^N/100g$, intermediate in Ratchaburi soil $0.85mg^N$, and least in Konosu soil $0.80mg^N/100g$. On the other hand, nitrogen fixing heterotrophic, bacteria, such as Clostridia, aerobes and anaerobes, were remarkably increased by application of rice straw while Azotobacter and Beijerinkia were not. The cumulative fixed nitrogen was more pronounced in the clay soil than in the coarse loamy soil. More pronounced nitrogen fixing activities in light condition(heterotrophic + photosynthetic) than that in dark(heterotrophic) condition have been observed both in the coarse loamy and clay soils. The nitrogen fixing ability of photosynthetic microbes in paddy soil is probably higher in coarse loamy soil than in clay soil.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.3
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• pp.264-271
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• 1988

This experiment was carried out to investigate the effects of long-term applications of organic matters on the chemical properties and on the application levels of nitrogen in Fluvio-Alluvial plain of Jeonbug series. The amounts of application of rice straw and compost, the sources of organic matters, were 500 and 1,000 kg/10a in combined with the different nitrogen levels of 0.15 and 20 kg/10a, respectively. The results obtained from the 9 year's experiment during 1979 to 1987 were summarized as follows: I. In long-term application of Organic matter the soil pH showed the lowest value in the 3rd-4th year at rice straw and 5th-6th year at compost but it varied less in control plot for 9 years. 2. Organic matter content in the soils was gradually increased by yearly application of organic matter, while it was higher in rice straw than in compost since the 5th year. 3. The contents of available silica and available phosphate in soil were rapidly increased by long-term application of organic matter and it was especially higher in rice straw than compost, but it was gradually decreased in control plot. 4. The contents of exchangable cations (Ca, Mg and K) and the total nitrogen were increased by long-term application of organic matter they were in rice straw than in compost. But they showed decreasing tendency in control plot. 5. The soil Eh was lower in order of rice straw, compost and control plot however application of orgnic matter resulted in increasing soil Eh due to the rapid reduction of soil from panicle formation to heading stage in rice cultivation. 6. The number of panicles per $m^2$ and the number of granis per panicle were increased by increment of nitrogen levels in all treatments and especially largest in rice straw application. But 1,000 grain weight increased in low nitrogen level with long-term applications of organic matter. 7. It was estimated that the application levels of nitrogen by long-term application of organic matter were 21, 24 and 20 kg/10a for 1st-3rd, 4th-6th and 7th-9th year in rice straw application, and 16 and 19 kg/10a for 1st-3rd and 4th-9th year in compost application, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.4
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• pp.431-438
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• 1983

Experiments were conducted to know the effects of 15 years successive application of fertilizers and organic matters on the soil properties, plant growth and yield of rice. Application of fertilizers and organic matters for 15 years in same plots were increased soil pH, OM, and CEC, but decreased $SiO_2$ and Ca content in paddy soil. Organic matter application for 15 years was increased OM about 0.5% compare to non-applied plot. Particulary lime application was increased soil pH, $SiO_2$, Ca and CEC in paddy soil. NPK+compost and NPK+straw application were increased number of panicles and number of spikelets per unit area, but decreased ripening ratio compare to NPK applied plot. Average grain yield for 15 years in the non-fertilized, -N, -P, -K, NPK+compost, NPK+straw and NPK+lime applied plot was 47, 51, 88, 95, 113, 117, and 106% of yield conpare to NPK applied plot, respectively.