• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1615-1615
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• 2001

During the past ten years, Near Infrared Spectroscopy has been successfully applied to the analysis of a great variety of agriculture products. Previous works (Morra et al., 1991; Salgo et al., 1998) have shown the potential of this technology for soil analysis, estimating different parameters just with one single scan. The main advantages of NIR applications in soils are the speed of response, allowing the increase of the number of samples analysed to define a particular soil, and the instantaneous elaboration of recommendations for fertilization and soil amendment. Another advantage is to avoid the use of chemical reagents at all, being an environmentally safe technique. In this paper, we have studied a set of 129 soil samples selected from representative glasshouse soils from Southern Spain. The samples were dried, milled, and sieved to pass a 2 mm sieve and then analysed for organic carbon, total nitrogen, inorganic nitrogen (nitrate ammonium), hygroscopic humidity, pH and electrical conductivity in the 1:1 extract. NIR spectra of all samples were obtained in reflectance mode using a Foss NIR Systems 6500 spectrophotometer equipped with a spinning module. Calibration equations were developed for seven analytical parameters (ph, Total nitrogen, organic nitrogen, organic carbon, C/N ratio and Electric Conductivity). Preliminary results show good correlation coefficients and standard errors of cross validation in equations obtained for Organic Carbon, Organic Nitrogen, Total Nitrogen and C/N ratio. Calibrations for nitrates and nitrites, ammonia and electric conductivity were not acceptable. Calibration obtained for pH had an acceptable SECV, but the determination coefficient was found very poor probably due to the reduced range in reference values. Since the estimation of Organic Carbon and C/N ratio are acceptable NIIRS could be used as a fast method to assess the necessity of organic amendments in soils from Mediterranean regions where the low level of organic matter in soils constitutes an important agronomic problem. Furthermore, the possibility of a single and fast estimation of Total Nitrogen (tedious determination by modifications of the Kjeldahl procedure) could provide and interesting data to use in the estimation of nitrogen fertilizer rates by means of nitrogen balances.

• Journal of Forest and Environmental Science
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• v.36 no.2
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• pp.91-112
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• 2020

In Ethiopia, dry land vegetation including the fairly intact lowland and western escarpment woodlands occupy the largest vegetation resource of the country. These forests play a central role in environmental regulation and socio-economic assets, yet they received less scientific attention than the moist forests. This study evaluated the woody plant species composition, population structure and carbon sequestration potential of the A. senegal woodland across three distance gradients from the settlements. A total of 45 sample quadrants were laid along a systematically established nine parallel transect lines to collect vegetation and soil data across distance gradients from settlement. Mature tree dry biomass with DBH>2.5 cm was estimated using allometric equations. A total of 41 woody plant species that belong to 20 families were recorded and A. senegal was the dominant species with 56.4 IVI value. Woody plant species diversity, density and richness were significantly higher in the distant plots compared to the nearest plots to settlement (p<0.05). The cumulative DBH class distribution of all individuals had showed an interrupted inverted J-shape population pattern. There were 19 species without seedlings, 15 species without saplings and 14 species without both seedlings and saplings. A significant above ground carbon (5.3 to 12.7 ton ha^-1), root carbon (1.6 to 3.6 ton ha^-1), soil organic carbon (35.6 to 44.5 ton ha^-1), total carbon stock (42.5 to 60.7 ton ha^-1) and total carbon dioxide equivalent (157.7 to 222.8 ton ha^-1) was observed consistently with an increasing of distance from settlement (p<0.05). Distance from settlement had significant and positive correlation with species diversity and carbon stock at 0.64^⁎⁎ and 0.78^⁎⁎. Disturbance intensity may directly influence the variation of species composition, richness and density along the A. senegal woodland. The sustainability of the A. senegal woodland needs urgent protection, conservation and restoration.

• Journal of Soil and Groundwater Environment
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• v.22 no.6
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• pp.74-84
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• 2017

Soil erosion is often extreme in Korea due to high rainfall intensities and steep slopes, and climate change has also increased the risk of erosion. Despite its significane, erosion-induced soil organic carbon (SOC) emission and water resource loss are not well understood, along with the lack of an integrated surface soil erosion protection policy. Therefore, to design adequate protection policies, land users, scientists, engineers and decision makers need proper information about surface soil and watershed properties related to greenhouse gas emission potential and water conservation capability, respectively. Assuming the total soil erosion of $346Tg\;yr^{-1}$, soil organic matter (SOM) content of 2% (58% of SOM is SOC), and mineralization rate of 20% of the displaced carbon, erosion-induced carbon emission could reach $800Gg\;C\;yr^{-1}$. Also the available water capacity of the soil was estimated to be 15.8 billion tons, which was 14 times higher than the yearly water supply demand in Seoul, Korea. Therefore, in order to prevent of soil erosion, this study proposes a three-stage plan for surface soil erosion prevention: 1) classification of soil erosion risk and scoring of surface soil quality, 2) selection of priority areas for conservation and best management practices (BMP), and 3) application of BMP and post management.

• Carbon letters
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• v.26
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• pp.66-73
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• 2018

We assessed the effects of combining bio-char with straw residue mulching on the loss of soil soluble nutrients and citrus yield in sloping land. The two-year study showed that straw residue mulching (ST) and bio-char application combined with straw residue (ST+BC) can significantly reduce soil soluble nutrient loss when compared with the control treatment (CK). The comparative volume of the soil surface runoff after each of the treatments was as follows: CK > ST > ST + BC. Compared with the CK, the runoff volume of the ST was reduced by 13.6 % and 8.5 % in 2014 and 2015, respectively. Compared with the CK, combining bio-char with the ST application reduced the loss of soluble nitrogen and improved the soil total nitrogen content reaching a significant level in 2015. It dramatically increased the soil organic matter content over the two year period (36.3% in 2014, 50.6% in 2015) as well as the carbon/nitrogen ratio (C/N) (16.6% in 2014 and 39.3% in 2015). Straw mulching combined with bio-char showed a trend for increasing the citrus yield.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.3
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• pp.251-256
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• 2015

The study was conducted to determine greenhouse gas (GHG) inventories in grasslands. After 'Low Carbon Green Growth' was declared a national vision on 2008, Medium-term greenhouse gas reduction was anticipated for 30% reduction compared to Business As Usual (BAU) by 2020. To achieve the reduction targets and prepare to enforce emissions trading (2015), national GHG inventories were measured based on the 1996 Intergovernmental Panel on Climate Change Guidelines (IPCC GL). The national Inventory Report (NIR) of Korea is published every year. Grassland sector measurement was officially added in 2014. GHG removal of grassland soil was measured from 1990 to 2012. Grassland area data of Korea was used for farmland area data in the "Cadastral Statistical Annual Report (1976~2012)". Annual grassland area corresponding to the soil classification was used "Soil classification and commentary in Korea (2011)". Grassland area was divided into 'Grassland remaining Grassland' and 'Land converted to Grassland'. The accumulated variation coefficient was assumed to be the same without time series changes in grassland remaining grassland. Therefore, GHG removal of soil carbon was calculated as zero (0) in grassland remaining grassland. Since the grassland area increases constantly, the grassland soil sinks constantly . However, the land converted to grassland area continued to decrease and GHG removal of soil carbon was reduced. In 2012 (127.35Gg $CO_2$), this removal decreased by 76% compared to 1990 (535.71 Gg $CO_2$). GHG sinks are only grasslands and woodlands. The GHG removaled in grasslands was very small, accounting for 0.2% of the total. However, the study provides value by identifying grasslands as GHG sinks along with forests.

• Journal of Forest and Environmental Science
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• v.31 no.4
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• pp.280-287
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• 2015

Soil samples were collected from three depths (0-10 cm, 10-40 cm and 40-80 cm) of two forest sites including one plantation dominated by teak with some other minor species and another degraded natural forest in Cox's Bazar, Bangladesh to compare their soil properties. Some vegetation parameters were also studied. For this study $10{\times}10\;m$ and $2{\times}2\;m$ quadrats were used for the tree and undergrowth parameters, respectively. Soil samples were also collected from these quadrats. Between the two forest types, the highest levels of organic carbon, total nitrogen, available phosphorus, exchangeable bases and cation exchange capacity (CEC) were found in soils of the plantation. The soils were acidic in nature and exchangeable Al concentrations were low. Teak dominated forest plantation had higher soil fertility index (SFI) than the degraded natural forest site. Steps for reforestation and appropriate protection are needed to improve the situation.

• Journal of Ecology and Environment
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• v.46 no.4
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• pp.282-291
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• 2022

Background: The Arctic permafrost stores enormous amount of carbon (C), about one third of global C stocks. However, drastically increasing temperature in the Arctic makes the stable frozen C stock vulnerable to microbial decomposition. The released carbon dioxide from permafrost can cause accelerating C feedback to the atmosphere. Soil organic matter (SOM) composition would be the basic information to project the trajectory of C under rapidly changing climate. However, not many studies on SOM characterization have been done compared to quantification of SOM stocks. Thus, the purpose of our study is to determine soil properties and molecular compositions of SOM in four different Arctic regions. We collected soils in different soil layers from 1) Cambridge Bay, Canada, 2) Council, Alaska, USA, 3) Svalbard, Norway, and 4) Zackenberg, Greenland. The basic soil properties were measured, and the molecular composition of SOM was analyzed through pyrolysis-gas chromatography/mass spectrometry (py-GC/MS). Results: The Oi layer of soil in Council, Alaska showed the lowest soil pH and the highest electrical conductivity (EC) and SOM content. All soils in each site showed increasing pH and decreasing SOC and EC values with soil depth. Since the Council site was moist acidic tundra compared to other three dry tundra sites, soil properties were distinct from the others: high SOM and EC, and low pH. Through the py-GC/MS analysis, a total of 117 pyrolysis products were detected from 32 soil samples of four different Arctic soils. The first two-axis of the PCA explained 38% of sample variation. While short- and mid-hydrocarbons were associated with mineral layers, lignins and polysaccharides were linked to organic layers of Alaska and Cambridge Bay soil. Conclusions: We conclude that the py-GC/MS results separated soil samples mainly based on the origin of SOM (plants- or microbially-derived). This molecular characteristics of SOM can play a role of controlling SOM degradation to warming. Thus, it should be further investigated how the SOM molecular characteristics have impacts on SOM dynamics through additional laboratory incubation studies and microbial decomposition measurements in the field.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.4
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• pp.227-230
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• 1973

To elucidate the effect of the organic carbon compounds included in a separate from glutamic acid fermentation residue (G. A. F. R) on the improvement of the physico-chemical properties of soil, on a soil low in organic matter content, treated with G. A. F. R and compost, observations on the total organic matter, humic acid, fulvic acid, C. E. C. and the development of aggregates were made. From the results of the investigations it was concluded that, the organic carbon compound in the tested G. A. R. F. is more effective than compost in increasing the total organic matter, humic acid, fulvic acid and C. E. C. of soil and in enhancing the development of soil aggregates.

• Environmental Engineering Research
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• v.22 no.4
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• pp.347-355
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• 2017

This study investigated how the combined changes in environmental conditions and nitrogen (N) deposition influence the mineralization processes and carbon (C) dynamics of wetland soil. For this objective, we conducted a growth chamber experiment to examine the effects of combined changes in environmental conditions and N deposition on the anaerobic decomposition of organic carbon and the emission of greenhouse gases from wetland soil. A chamber with elevated $CO_2$ and temperature showed almost twice the reduction of total decomposition rate compared to the chamber with ambient atmospheric conditions. In addition, $CO_2$ fluxes decreased during the incubation under the conditions of ambient $CO_2$ and temperature. The decrease in anaerobic microbial metabolism resulted from the presence of vegetation, which influences the litter quality of soils. This can be supported by the increase in C/N ratio over the experimental duration. Principle component analysis results demonstrated the opposite locations of loadings for the cases at the initial time and after three months of incubation, which indicates a reduction in the decomposition rate and an increasing C/N ratio during the incubation. From the distribution between the decomposition rate and gas fluxes, we concluded that anaerobic decomposition rates do not have a significantly positive relationship with the fluxes of greenhouse gas emissions from the soil.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.191-194
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• 2002

Humic acid, fulvic acid and humin present in volcanic ash soil were isolated by IHSS standard procedure and their characteristics were analyzed as a basic study to evaluate the effect of humic substances on the behaviour of pollutants in contaminated surface soil. The volcanic ash soil contained 42.1 % of total organic matter based on the oven-dried soil, and humin, humic and fulvic acids corresponded to 67.5 %, 15.2 %, 7.6 % of TOM respectively. Structural informations of the humic fractions were obtained from their elemental analysis and IR, CPMAS C-13 NMR spectral analysis and the differences among them are discussed with their C/H, O/C ratios and distributions of carbon types in the molecules.