• Journal of the Korean GEO-environmental Society
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• v.2 no.1
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• pp.23-30
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• 2001

A Series of laboratory tests were conducted to investigate the engineering characteristics for organic soil widely distributed in Yong-dong region which always makes problems in construction works. Physical characteristics of Yong-dong organic soil area were measured in terms of such categories as nature water content, organic content, specific gravity, liquid limit, and plasticity index. As a result, it was found that nature water content was $50.8^{\circ}-343.5%$, organic content 12.1-42.5%, specific gravity 1.76-2.71, liquid limit 46.6-440.2%, and plasticity index 9.2-557.2%. Also, as consolidation load increases, consolidation coefficient slightly decreases with small up and down. The ratio of secondary consolidation coefficient to compression index is 0.001-0.091 $C_a/C_c$, secondary coefficient tends to increase greatly when organic content is in the range of 11-22%.

• Journal of Applied Biological Chemistry
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• v.50 no.2
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• pp.88-96
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• 2007

Organic farming systems based on ecological concepts have the potential to produce sustainable crop yields with no decline in soil and environmental qualities. Recent expansion of sustainable agricultural systems, including organic farming, has brought about need for development of sustainable farming systems based on value judgments for key properties of importance for farming. Chemical and microbiological properties were chosen as indicators of soil quality and measured at soil depth intervals of 5-20 and 20-35 cm in conventional and organic-based apple orchards located in Yeongchun, Gyeongbuk. The orchards were two adjacent fields to ensure the same pedological conditions except management system. Soil pH in organic farming was around 7.5, whereas below 6.0 in conventional farming. Organic farming resulted in significant increases in organic matter and Kjeldahl-N contents compared to those found with conventional management. Microbial populations, biomass C, and enzyme activities (except acid phosphatase) in apple orchard soil of organic farming were higher than those found in conventional farming. Higher microbial quotient ($C_{mic}/C_{org}$ ratio) and lower microbial metabolic quotient for $CO_2(qCO_2)$ in organic farming confirmed that organic farming better conserves soil organic carbon. Biological soil quality indicators showed significant positive correlations with soil organic matter content. These results indicate organic-based farming positively affected soil organic matter content, thus improving soil chemical and biological qualities.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.556-562
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• 2013

The blueberry eco-friendly farming requires the soil condition of pH 4.2 ~ 5.2 and high in organic matters for stable growth. Most of soil types of blueberry-growing land in Korea, however, belongs to alkaline soils with low organic matter content. As a result, the eco-friendly blueberry growers use peat moss and sulfur powder heavily to improve the soil condition, but the guideline on the effective use of organic materials was not established yet. Therefore, this sturdy was performed to investigate the effect of increasing soil acidity and organic matters by using organic materials. Among 5 organic materials, the pH of soil was lowest in degradable sulfur + bentonite (pH 4.1) and followed by Peat moss+Chaff+Pine Needlesmixtures(pH 4.5), OrganicAcid +vinegar (pH 4.7), Sulfur powder (pH 4.8), Temperature response Elutioner (pH 5.2). The soil organic matter content were increased in the following order: Peat moss+Chaff+Pine Needlesmixtures (8.4%) > degradable sulfur + bentonite (7.8%) > Organic Acid + vinegar (7.2%) > Sulfur powder ${\fallingdotseq}$ Temperature response Elutioner (6.3%). Although different in the degree, all organic materials treated was recognized a good material for improving soil pH and organic matter content. The plant height and stem diameter of blueberry were no clear difference among 5 organic materials. Another study was carried out to investigate amending soils with organic matter by soil mulching with pine needles for soil surface management in blueberry organic cultivation. The effect of increasing the soil pH by pine needle mulching in blueberry eco-friendly farming was recognized in four test fields. Pine needle mulching for soil surface management in blueberry appeared several advantages, such as improving of soil pH and organic matter content. Therefore, pineneedle mulching in blueberry organic farming is considered as the most efficient means of mulching cultivation for amending soil pH, weed suppression and moisture conservation among mulching materials.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.3
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• pp.47-55
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• 2011

Cicada is a very familiar insect to people but habitat characteristics of them are not well known. To investigate habitat characteristics of cicada nymph, plant species, plant cover, soil hardness, accumulated organic mass, organic content in soil, and root density were investigated at 11 sites in an apartment complex garden in Seoul. Selected sites had different densities of cicada nymph case above the ground. Density of cicada nymph case was positively correlated with accumulated organic mass, organic content in soil, and root density and negatively correlated with soil hardness. Even though shrub coverage was not linearly correlated with the density of cicada nymph case, 80% cover of shrub was necessary for the high density of them. Data in this study suggested that organic matter in addition to root density be the primary limitation factor of cicada nymph and high amount of litter-fall decrease soil hardness through the increase of soil organic matter. This study suggests that the density of cicada nymph can be managed through organic content in soil.

• Journal of Biosystems Engineering
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• v.26 no.5
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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.

• Journal of Ginseng Research
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• v.42 no.4
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• pp.532-539
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• 2018

Background: Heat treatments are applied to ginseng products in order to improve physiological activities through the conversion of ginsenosides, which are key bioactive components. During heat treatment, organic acids can affect ginsenoside conversion. Therefore, the influence of organic acids during heat treatment should be considered. Methods: Raw ginseng, crude saponin, and ginsenoside $Rb_1$ standard with different organic acids were treated at $130^{\circ}C$, and the chemical components, including ginsenosides and organic acids, were analyzed. Results: The organic acid content in raw ginseng was 5.55%. Organic acids were not detected in crude saponin that was not subjected to heat treatment, whereas organic acids were found in crude saponin subjected to heat treatment. Major ginsenosides ($Rb_1$, Re, and $Rg_1$) in ginseng and crude saponin were converted to minor ginsenosides at $130^{\circ}C$; the ginsenoside $Rb_1$ standard was very stable in the absence of organic acids and was converted into minor ginsenosides in the presence of organic acids at high temperatures. Conclusion: The major factor affecting ginsenoside conversion was organic acids in ginseng. Therefore, the organic acid content as well as ginsenoside content and processing conditions should be considered important factors affecting the quality of ginseng products.

• Korean Journal of Organic Agriculture
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• v.19 no.4
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• pp.513-528
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• 2011

This study was conducted to evaluate the nutritional value of locally produced organic agricultural by-products to substitute imported organic feeds for organic ruminant farming. Imported organic feeds (corn grain, soybean meal, soybean seed, oat grain, barley grain, wheat grain, buckwheat, sunflower seed meal) and byproducts (rice bran, grape seed meal, rice straw, soybean hull, soybean curd, rice hull, green kernel rice, and crushed rice grain) were analyzed for chemical composition and NDF, ADF, mineral, and amino acid contents and anti-nutritional factors. Dry matter, NDF and ADF contents in organic feeds were higher than those in conventional feeds. Especially, the 9.65% fat content of organic soybean meal was 6 times higher than the 1.95% fat content of conventional soybean meal. Fat contents of rice bran, grape seed meal, green kernel rice, and crushed rice grain were 25.66, 6.09, 3.57 and 1.59%, respectively. Protein contents of soybean hull and soybean curd were 14.68 and 19.87%, respectively, which are highest among organic by-products. Levels of aflatoxin in all feeds were below the safety level. Therefore, organic rice bran, green kernel rice and crushed rice as energy source, and soybean hull and soybean curd as protein source could partial replace imported feeds for organic ruminant farming.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.242-246
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• 2011

Organic kiwifruit orchard soils were compared with conventional ones in Korea. Soil structure of organic soil had higher gaseous and liquous phase as well as soil porosity in the surface soil. Although the nutritional level of each orchards were quite different among soils, the analysis of both system revealed that organic kiwifruit orchard soil had similar or even higher nutrient level (N and organic matter content in surface soil) compared to conventional ones. The organic matter content of deep soil also had the high tendency in deep soil of organic soil. Higher level of nitrogen in organic surface soil is presumably due to the excessive application of organic compost and liquid fertilizer rather than the contribution by grasses such as green manure. Available phosphorous level of organic system was quite high but similar in surface soil of both system, compared to the recommended level. Potassium, calcium and magnesium levels were also enough in organic kiwifruit orchard soils.

• Journal of Environmental Science International
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• v.8 no.5
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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.

• Korean Journal of Organic Agriculture
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• v.15 no.3
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• pp.309-318
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• 2007

The effects of supplementation of organic citrus on the quality of rice straw silage was investigated in this study. The aim of the study was to improve the quality of rice straw silage using agricultural by-products and therefore to secure the good quality forage sources. Firstly, looking at chemical composition of citrus added rice straw silage, crude protein content appeared improved with the addition of citrus to rice straw silage compared to control while NDF and ADF contents decreased. pH of the silages were different between control(4.39) and treatments$(3.47\sim3.53)$. Lactic acid content was higher in citrus added silage(4.87mM) than in control (3.65mM). External quality of the silages was also better in citrus added silage when citrus added at the equal ratio with rice straw(1 : 1). This trend was the same as with pH and lactic acid content. Propionate was significantly higher in citrus addd silage but butyrate was significantly lower. DM and NDF disappearance rates in the rumen were highest when citrus added at the equal ratio with rice straw(1:1). In conclusion, supplementation of citrus to rice straw silage with equal ratio contributed the best to the improvement of the quality of silage and it may have been due mainly to abundant content of non-structural carbohydrate in citrus.