• Korean Journal of Soil Science and Fertilizer
• /
• v.26 no.2
• /
• pp.121-126
• /
• 1993

The behaviors of inorganic nitrogen derived from solid animal waste in soil has been received too much concern partly because nitrate which occurred from nitrification can act as a pollutant to soil and groundwater and partly because the loss of nitrogen from surface soil by downward movement of water is disadvantageous in the view of plant nutrient. This present study was conducted to get fundamental imformations on nitrogen behavior and to provide improved basical concepts on the management of animal waste. Fresh or fermented pig manure was mixed with a sandy loam soil in the ratio of 2:1(soil:pig manure), packed into test tube and incubated at $30^+/-1^{\circ}C$ for 8 weeks under aerobic- or anaerobic condition. Sample tubes were taken at the one week interval and analyzed on pH, the amount of $CH_4$ produced under anaerobic condition and inorganic nitrogen. The pH of soil treated with fresh pig manure under anaerobic condition was lowered by 1.87 unit compared to that of under aerobic condition, but at the treatment with fermented pig manure, pH change was very little between aerobic and anaerobic condition. The coefficients of regressional equations which were obtained from pH and incubation time were -0.114 in fresh pig manure and -0.089 in fermented pig manure, and the extent of pH decrease due to incubation was greater in fresh pig manure than that of fermented pig waste. No differences in the amounts of $CH_4$ produced under anaerobic condition between fresh and fermented pig manure was observed until 3 weeks of incubation, however, after that the amount of $CH_4$ produced in fresh pig manure was abruptly increased and cumulative amont of $CH_4$ was reached 8.6 mole/g. K values on $CH_4$ production in fresh and fermented pig manure was 0.211 mole/g/day and 0.046 mole/g/day, respectively, for 5 weeks from the 3rd to the 8th week. $NH_4-N$ concentration at aerobic condition with fresh pig manure treatment was lowered by passing time of incubation, but $NO_3-N$ concentration was elevated from 11.2 ppm at initial state to 67.3 ppm after incubation and this trend on $NH_4-N$, $NO_3-N$ concentration was very similar to the treatment of fermented pig manure. While $NH_4-N$ concentration under anaerobic condition was greatly increased. $NO_3-N$ concentartion was not only very low but also no great changes, that was ranged from 4 to 8 ppm.

• Journal of Korean Society of Forest Science
• /
• v.86 no.2
• /
• pp.186-199
• /
• 1997

The soils derived from granite gneiss occupy almost one third of the land area in Korea. The soils under forest vegetation, formed on granite gneiss, in Sun chon-shi, Chollanam-do in southern part of Korea, were studied to evaluate the weathering and the transformation of primary minerals into secondary minerals, clay minerals. The studied soils contained large amounts of ferromagnesian minerals, weathered biotites and were well weathered, strongly acid and low in organic matters and in ration exchange capacity. The clay contents in the Bt horizon were almost two times higher than those in the C horizon. The O horizon had a thin layer which consisted of a little decomposed plant components with a granic fabric and high porosity, and showed the micromorphological characteristics of moder humus. The related distribution pattern of the E horizon were enaulic and large amounts of silts and small amounts of sand grains were another characteristics of the E horizon. The most striking micromorphological features were multilaminated clay coating and infillings in the voids in the Bt and C horizons, and generally limpid ferriargillans ejected from the biotites and imparted red color to the soils in the Bt horizon. High clay contents in the Bt horizon was not only due to clay translocation, but also due to intensive in situ mineral weathering in this horizon. The most significant pedogenic process, revealed by the petrographic microscope and SEM, was the formation of iron oxides from biotites, the formation of tubular halloysites and the weathering models of biotites; wedge weathering and layer weathering. The thick coating on the weathering biotites showed the characteristics of the weathering process and the synthetic hematites were revealed in clays by TEM. Total chemical analysis of clays revealed extensive loss of Ca, and Na and the concentration of Fe and Al. Mineralogical studies of clays by XRD showed that micas were almost completely weathered to kaolinite, vermiculite-kaolinite intergrade, hematite, gibbsite, while halloysites from other primary minerals. Some dioctahedral mica appeared to be resistant in the soils. Parent rock of the soils contained a considerable amounts of biotites and this forest soils showed especially a dominant characteristics of biotite weathering.

• Korean Journal of Environment and Ecology
• /
• v.23 no.5
• /
• pp.447-459
• /
• 2009

This study is intended to provide basic date for the efficient management of Pinus densiflora community by analyzing ecological characteristics of Pinus densiflora inhabiting Byeonsanbando National Park. According to investigations, P. densiflora community and P. densiflora-Quercus community are widely distributed, occupying 40.3% of the total area. 21 sites ($400m^2$per site) are selected for TWINSPAN analysis, and the result indicates that the whole community of P. densiflora and P. densiflora-Quercus can be classified into 8 types, and the age of P. densiflora is 40-50 years, which is similar to that of deciduous broad-leaved trees. The 8 community types are: P. densiflora community which competes with Quercus variabilis; P. densiflora community in which Fraxinus sieboldiana and Quercus serrata grow in the understory layer; P. densifloa community in which Q. serrata grow in the understory layer and Smilax china var. microphylla in the shrub layer respectively; P. densifloa community in which P. densiflora and F. sieboldiana grow in the understory layer; P. densiflora community which competes with Q. serrata and Carpinus tschonoskii; P. densiflora community which competes with Q. variabilis and Q. serrata; P. densiflora community in which Prunus sargentii grow; P. densiflora community in which Abies holophylla grow. P. densiflora community which competes with Q. variablis and C. tschonoskii seems to be in a stage of succession to deciduous broad-leaved community. The analysis indicates that Shannon diversity index is 0.2756-1.3879. It also indicates that there is a negative correlation between P. densiflora and Q. variabilis and C. tschonoskii; there is a positive correlation between P. densiflora and F. sieboldiana and Rhododendron schlippenbachii. These investigations show that the transformation of vegetation is already under way. There is a possibility that ecological succession can take place in 30.4% of the total area from P. densiflora to Quercus and deciduous broad - leaved trees. Therefore, it is recommended that the preservation and maintenance of P. densiflora be implemented by taking control of competing species which undermine the stability of P. densiflora forest community.

• Korean Journal of Soil Science and Fertilizer
• /
• v.3 no.1
• /
• pp.55-59
• /
• 1970

In an effort to determine the bio-synthesis in the soybean as investigate to the variance of each substance: Glutamic acid, Aspartic acid and its amides during the growth of younger soybean plants. 1. The variance-curve of Gultamic acid and Aspartic acid as the acidic amino acids in the cotyledons was appeared the peak the first half period at Glutamic acid and the latter half at Aspartic acid in the growth of soybeans, and was received the symmetrical impression centering around the stage of adult leaf-development. But, in the embryonic organ, it appears the peak at both part, in the developmental stage of adult leaf and also appears near phenomena of increase and decrease in the variation-curve of metabolites. 2. It's amides-Gultamine and Asparagine-appears the peak at the developmental stage of adult leaf in the both cotyledons and embryonic organ, and rapid increase in the cotyledons were very impressed compare with the decrease at fallen stage of cotyledons in the embryonic organs. 3. In the relation of variance at Glutamic acid and Aspartic acid, both substance were discovered the fact of translocation from cotyledon to embryonic organ, and Glutamic acid could supposed that bear the charges of outrider substance in other amino acid as the Glutamic acid-self and major basic function for receiving the ammonia as the nitrogen contain constituent of plant. In the case of Glutamine, formation-mechanism of ammonia which develops due to its hydrolysis in the latter period of soybean growth, suggested that was forfeit its function till instance of fallen cotyledons. 4. In the relation the Aspartie acid and Asparagine, Aspartic acid which begins to decrease from seed-state was supposed that bear sufficiently the charge of outrider substance in the formation of Asparagine other than translocated to embryonic organ from cotyledon. And, formation-theory of Aspartic acid which suppose as formational substance from Kreb's cycle were recognized from latter period of soybean growth, and then, rapid accumulation of Asparagine's amounts were supposed that adapt to two theory: Theory which consider to transformation as Asparagine state for pressing to less than noxious weight the concentration of ammonia developing from the cells, and was formate and accumulate as ammonia or carbohydrates containing excess in the cotyledons.

• Korean Journal of Breeding Science
• /
• v.50 no.4
• /
• pp.463-471
• /
• 2018

Perilla is an oilseed crop cultivated in Korea since ancient times. Due to the high ${\alpha}-linolenic$ acid content in perilla, perilla seed oil can easily become rancid. ${\alpha}-Linolenic$ acid is synthesized by two enzymes, endoplasmic reticulum-localized ${\Delta}15$ desaturase (FAD3) and chloroplast-localized ${\Delta}15$ desaturase (FAD7) in vivo. In order to lower the ${\alpha}-linolenic$ acid content of the seed oil without disturbing plant growth, we tried to suppress the expression of only the FAD3 gene using RNA interference, whilst maintaining the expression of the FAD7 gene. Seventeen transgenic plants with herbicide ($Basta^{TM}$) resistance were obtained by Agrobacterium-mediated transformation using hypocotyls of perilla plants. The transgenic plants were firstly confirmed by treatment with 0.3% (v/v) $Basta^{TM}$ herbicide, and the expression of FAD3 was measured by Northern blot analysis. The ${\alpha}-linolenic$ acid content was 10-20%, 30-40%, and 60% in two, seven, and three of the twelve $T_1$ transgenic perilla plants which had enough seeds to be analyzed for fatty acid composition, respectively. Analysis of the fatty acid composition of $T_2$ progeny seeds from $T_1$ plants with the lowest ${\alpha}-linolenic$ acid content showed that the homozygous lines had 6-10% ${\alpha}-linolenic$ acid content and the heterozygous lines had 20-26% ${\alpha}-linolenic$ acid content. It is expected that the reduction in ${\alpha}-linolenic$ acid content in perilla seed oil will prevent rancidity and can be utilized for the production of high-value functional ingredients such as high ${\gamma}-linolenic$ acid.

• Journal of Wetlands Research
• /
• v.24 no.4
• /
• pp.345-353
• /
• 2022

A wastewater treatment plant (WWTP) is a major gateway for the engineered nano-particles (ENPs) entering the water bodies. However existing studies have reported that many WWTPs exceed the No Observed Effective Concentration (NOEC) for ENPs in the effluent and thus they need to be designed or operated to more effectively control ENPs. Understanding and predicting ENPs behaviors in the unit and \the whole process of a WWTP should be the key first step to develop strategies for controlling ENPs using a WWTP. This study aims to provide a modeling tool for predicting behaviors and removal efficiencies of ENPs in a WWTP associated with process characteristics and major operating conditions. In the developed model, four unit processes for water treatment (primary clarifier, bioreactor, secondary clarifier, and tertiary treatment unit) were considered. Additionally the model simulates the sludge treatment system as a single process that integrates multiple unit processes including thickeners, digesters, and dewatering units. The simulated ENP was nano-sized TiO₂, (nano-TiO₂) assuming that its behavior in a WWTP is dominated by the attachment with suspendid solids (SS), while dissolution and transformation are insignificant. The attachment mechanism of nano-TiO₂ to SS was incorporated into the model equations using the apparent solid-liquid partition coefficient (Kd) under the equilibrium assumption between solid and liquid phase, and a steady state condition of nano-TiO₂ was assumed. Furthermore, an MS Excel-based user interface was developed to provide user-friendly environment for the nano-TiO₂ removal efficiency calculations. Using the developed model, a preliminary simulation was conducted to examine how the solid retention time (SRT), a major operating variable affects the removal efficiency of nano-TiO₂ particles in a WWTP.