• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.96-106
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• 1998

Rice plants were grown for 42 days in the specially made micro-ecosystem(pot) containing two different soils treated with fresh and 60-day-aged residues of [$^{14}C$]quinclorac, respectively, to elucidate the behaviour of the herbicide quinclorac residues in the soils. Amounts of $^{14}CO_{2}$ evolved from two soils treated with different residues with and without vegetation were all less than 2.2% of the total $^{14}C$, indicating that there was little microbial degradation of quinclorac in soil. $^{14}C$-Radioactivity absorbed and translocated into rice plants from soil A and B containing fresh quinclorac residues was 8.4 and 24.2%, respectively, of the originally applied $^{14}C$, while 5.5 and 17.7%, in aged residue soils. These results indicate that larger amounts of $^{14}C$ were absorbed by rice plants from soil B with less organic matter and clay than soil A, and the uptake of [$^{14}C$]quinclorac and its degradation products decreased with aging in soil. After 42 days of rice growing, 84.5 and 61.8% of the $^{14}C$ applied freshly to soil A and B, respectively, remained in soil, whereas, in the case of aged soils, 86.3 and 67.7% of the $^{14}C$ applied did. Meanwhile, without vegetation, more than 98.3% of the $^{14}C$ applied, in both fresh and aged residues, remained in soil, suggesting that quinclorac was relatively persistent chemically and microbiologically. Most of the non-extractable soil-bound residues of [$^{14}C$]quinclorac were incorporated into the organic matter and largely distributed in the fulvic acid portion.

• Journal of Animal Environmental Science
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• v.10 no.2
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• pp.101-110
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• 2004

A solid of Thermophilic Aerobic Oxidation(TAO) System was mixed with sawdust or a rice husks. After fermentation was finished, molding machine and a dryer were used, and pellet fertilizer was produced. The fertilizing experiment was carried out as five pieces by Bed soil, TAO solid(TAO-S), TAO pellet fertilizer(TAO-PF), Chemical fertilizer(NPK) and Control(no fertilizer). Growth rate of the Chinese cabbage by each treatment was examined. Analysis of microbe and soil characteristic before and after crop experiment were carried out. When the moisture contents of TAO-PF were $18\%$ and $25\%$, the occurrence rate of microbes for the storage time was increased to $80\%$ and $100\%$ respectively. However, in the $12\%$ of water content treatment was not increased microbes. The concentration of soil bacteria in TAO-PF and TAO-S for 15 day after treatment was $1.5\times10^7\~8.0\times10^7$ CFU/ml, and the concentration of bacteria for 50 day was increased to $6.3\times10^7$ and $8.3\times10^7$ CFU/ml. However, Fungus decreased. The concentration of Actinomycetes was increased in TAO solid, Bed soil and TAO-PF treatment. The TAO-S and TAO-PF treatment were normal to compare to the NPK treatment. In this experiment the height and width of the Chinese cabbage were 22.3 cm, 16.8 cm in Bed soil and 28.8 cm, 21.3 cm in TAO solid. The leaf number of TAO-S, TAO-PF and NPK treatment were similar to 39.8, 38.3, 40.3 sheet. As the result, the TAO-PF knew that use was possible with fertilizer.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.6
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• pp.301-306
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• 2005

Asian dust was collected in Korea and soils in the arid area of northern China were analysed for its physical and chemical properties, and mineral compositions for in order to interpret the origin of Aeolian soils and estimate the effect of dust wind on the soil environment in Korea. Asian dust was collected at Suwon in Korea from 2002 to 2004. Soil samples were collected from the desert and Loess plateaus around Gobi desert in China. As a result of analysis of desert soil distributed on northern region and Loess soils in China, it was observed that soil pH was about 9, organic matter 11 to $23g\;kg^{-1}$, and CEC 7.1 to $18.4cmolc\;kg^{-1}$, showing a high spatial variation among different sampling locations. About 62 to 80% of particles were composed of quartz and feldspars, 2 to 14% calcite ($CaCO_3$) and dolomite [$Ca{\cdot}Mg(CO_3)_2$], and trace other clay minerals. All the dust particles in Korea were below 50 m in diameter, and the mineral compositions were quartz, mica, feldspar and some clay minerals. Major components of clay mineral of Asian dust was mainly illite as compared to the kaolin of soils in Korea. The base saturation of exchangeable Ca, Mg, K and Na in the Asian dust was above 250% due to the high content calcite. Most of upland soil in Suwon was thin and sharp type, but Asian dust in Korea was the spherical shape. Asian dusts in Suwon, Korea, did not show a definite mineralogical variation of the dust during the collection period. Difference between the Asian dust collected in Korea and the soils in arid area of China was observed in the physical and chemical properties, especially for particle size distribution, cations such as Ca, Mg, K and Na. However, some similarities were found on the mineral compositions and chemical properties between Asian dust collected in Korea and the loess of China.

• Korean Journal of Microbiology
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• v.42 no.1
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• pp.47-53
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• 2006

A streptomycete strain was isolated from the soil samples from Korea. The chemotaxonomy and 16S rDNA sequencing confirmed that the strain belonged to the genus Streptomyces and we named it Streptomyces sp. AO-0511. Two antibiotics, herbimycin A and dihydroherbimycin A produced by this strain were tested for their physico-chemical and biological characteristics. Both compounds were stable under acidic pH. Dihydroherbimycin A was more heat-stable and polar compared with herbimycin A. Only weak antibacterial activities were detected against Bacillus subtilus ATCC 6633 and Micrococcus luteus ATCC 9341. However, herbimycin A and dihydroherbimycin A showed strong inhibitory activities on lung cancer cells (A549 cells) and leukemia cells (HL-60). The cytotoxicity was determined using L5178Y and P388 cell lines. The results showed that herbimycin A and dihydroherbimycin A had lower toxic effects on the cells compared with the standard compounds, comptothecin and cyclosporin A. Therefore, both compounds could be good candidates for the development of new anticancer drugs.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.2
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• pp.134-144
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• 2001

This study was conducted to investigate physicochemical and microbiological properties during composting process when pig manure was composted with some bulking agents(Saw dust, Rice hull, Crushed wood). The pig manure consisted of 2.95% total nitrogen, 4.55% $P_2O_5$, 2.07% $K_2O$, 81.2% organic matter and 14.0 C/N, dry base. The inorganic content of bulking agents were similar one another, and C/N ratio was Saw dust 392. Rice hull 91.5, Crushed wood 266. The temperature of Saw dust composting slowly increased at initial stage, whereas one of Rice hull and Crushed wood rapidly increased and stabilized similarly to outdoor temperature after about 2 month. The pH of compost increased during initial 1 month after decreasing, but thereafter decreased rapidly. The C/N ratio rapidly decreased at initial stage, and it slowly decreased after 1 month. Total nitrogen somewhat increased according to composting process. Ammonium-nitrogen increased until 60th day, and thereafter it was rapidly inclined to decrease. The population of aerobic bacteria, Bacillus spp., actinomycetes and fungi increased up to > $10^{10}cfu\;g^{-1}$ fresh weight, > $10^7$, > $10^8$ and > $10^6$, respectively in Rice hull and Crushed wood composting, and more than ones in Saw dust composting, and specially actinomycetes. The persuasive Bacillus spp. isolated from composting process were B. lentimorbus, B. licheniformis, B. pumilus, B. megaterium, etc.

• Journal of Plant Biotechnology
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• v.48 no.2
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• pp.77-85
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• 2021

Hydroponic cultivation, in which crops are grown without soil and are unaffected by the weather, has many advantages over conventional soil cultivation. The crop's growth can be further accelerated by using nutrient solution in place of water. This study investigated the growth and physicochemical properties of hydroponic barley sprouts under various nutrient solution and artificial light treatments. The shoot, root, and total plant length increased over time, with the fastest growth occurring in the nutrient solution and light-emitting diode (LED) treatments. Fresh and dry plant weights were higher in the fluorescent lamp treatment than in the LED treatment. Barley sprout powder color differed slightly by treatment, with the Hunters L value ranging from 50.79 to 53.77; Hunters a value from -6.70 to -4.42; and Hunters b value from 13.35 to 14.76. The Hunters L and Hunters b values were highest in the LED treatment, whereas the Hunters a value was relatively highest in the fluorescent lamp treatment. The total phenol content was higher in the control than in the nutrient solution treatment; however, the total flavonoid content showed the opposite pattern to that of total phenol content, being highest in plants that were grown in nutrient solution. The Trolox equivalent antioxidant capacity (TEAC) was higher in the control group than in the nutrient solution group. The ferric ion reducing antioxidant power (FRAP) was higher in the fluorescent treatment group than in the LED treatment group. The total amino acid composition ranged from 106.82 to 122.63 mg/g dry powder, with the essential amino acid composition ranging from 47.01 to 56.19 mg/g, and non-essential amino acid composition from 67.86 to 77.66 mg/g. The most frequently detected compositional amino acid was aspartic acid, followed by glutamic acid, alanine, leucine, and valine.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.279-286
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• 2013

BACKGROUND: Soil incorporation of green manure crop(GMC) is one of the methods for reducing continuous cropping injury and increasing yield of carrot. The purpose of this study was to evaluate the effects of green manure crops on growth and yield of carrot for reduction of continuous cropping injury of carrot through crop rotation. METHODS AND RESULTS: To reduce the injury by continuous cropping system(CCS) of carrot cultivation, GMCs such as crotalaria and sudangrass were applied, which GMC was sowed in latter-June and returned to soil in latter-October. Nutrient contributions of N, $P_2O_5$, $K_2O$, CaO, and MgO in crotalaria were 8.3, 7.5, 4.4, 7.8, and 2.1 kg/10a, respectively. Nutrient contributions of N, $P_2O_5$, $K_2O$, CaO, and MgO in sudangrass were 8.4, 8.6, 26.8, 0.3, and 2.7 kg/10a, respectively. After incorporation of GMCs into soil, bulk density in soil with GMCs was lower than that in soil without GMCs(control). In soil after incorporation of GMCs, pH was not different in all treatment conditions, and ranged from 6.37~6.64. EC in soil after incorporation of GMCs was lower than that in soil without GMCs. The OM, T-N, and avail. $P_2O_5$ contents in soil with GMCs were higher than those in soil without GMCs. The growth and yields were increased as 39.2%(6,226 kg/10a) in the rotational cropping system(RCS) as compared to continuous cropping system(control and without NPK) of 4,473 kg/10a. Crotalaria cultivation were the most effective crop for reducing the injury of continuous cropping of carrot. CONCLUSION(S): This study suggest that the RCS using GMCs showed lower disease outbreak density in soil for carrot cultivation as compared to CCS without GMCs. Especially, the GMCs good effect for reduction of continuous cropping injury of carrot.

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.132-138
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• 2005

Objective of this research was to evaluate the fate of nitrogen and phosphorous in hydroponic waste solution from the plastic film house cultivation applied to the upland soil by column leaching and field experiment. The pH and EC of leachate were decreased by the reaction with the upland soil in the column leaching experiment. The EC and concentrations of $H^+,\;K^+,\;and\;{NH_4}^+$ of leachate were decreased as the column length (soil depth) was increased. But these were increased as the amounts of the hydroponic waste solution were increased field experiment growing red pepper (Capsicum annum L.) to monitor the nutrients movement using ion exchange resin capsule demonstrated that the nutrient concentration of soil solution was increased in the orders of $PO_4-P. Nitrate concentration of resin capsule inserted into the soil was relatively higher than other nutrients $(NH_4-N\;and\;PO_4-P)$ at the 45 cm of soil depth. The overall results demonstrated that the hydroponic waste solution could be recycled as plant nutrients to enhance fertility of soils. But nitrate leaching was a major factor for safe use of the hydroponic waste solution in soil.

• Current Research on Agriculture and Life Sciences
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• v.21
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• pp.39-47
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• 2003

The object of this study was to analyze influence which Black locust afforestation affected to soil, to research change of soil environment of Black locust planted stand and adjacent stands through comparative analyzing physichemical property of soil of them. It was investigated that the soil texture of Black locust planted stand and the adjacent stands was mostly SL. and LS. According to this result I could know that transformation of soil texture by vegetation easily happened because transformation soil texture results from the parent rock. I could ascertain that difference existed between Black locust planted stand and the other stands in soil pH and Carbon content of planted stand of Black locust pH, contents of Available $P_2O_5$ Carbon, Total Nitrogen. In other words, pH and Carbon content of Black locust planted stand were lower than that of Oak forest, higher than that of Pine forest. These results showed that Black locust was which fix nitrogen. I could infer that Black locust afforestation made forest soil fertilized. In soil of Black locust planted stand and the adjacent stands, statistical value appeared highly in pH and existed in content of Carbon, Total nitrogen, too. And high interrelationship appeared in the order of pH, C/N Ratio, CEC, Total nitrogen content was in each stands. I suppose that the trespassing extent of Black locust to Oak forest and Pine forest which are adjacent to planted stand of Black locust is different because of low pH, lackness of Available $P_2O_5$ Carbon, and what not.

• Korean Journal of Environment and Ecology
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• v.27 no.4
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• pp.498-506
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• 2013

In order to identify soil characteristics and to estimate the age of wetland, soil samples of Mt. Sohwangbyoung wetland and Jilmoi wetland known as peatland in Odaesan National Park.were collected and analyzed. Soil pH of Mt. Sohwangbyoung wetland and Jilmoi wetland showed average pH of 5.5, and did now show any significant difference according to the time and plant community. Total ionic content of soil showed different values among plant communities, but no difference by time in each plant community. Soil exchangeable cations such as Na, K and Mg showed a similar pattern of total ionic content. Unlike other cations, however, Ca content showed significant differences according to the plant community and time. Soil organic matter and total nitrogen contents showed remarkable differences according to plant community, and especially showed very low valeus at the place where Sphagnum palustre distributes. Based on the results of the above, Mt. Sohwangbyoung wetland and Jilmoi wetland can be considered as weakly acidic bog. From age analysis, two wetlands are estimated to have been formed before 100 AD for Mt. Sohwangbyoung wetland and 1448 AD for Jilmoi wetland, respectively.