• Korean Journal of Organic Agriculture
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• v.9 no.1
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• pp.17-27
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• 2001

To clarify the proper and safe duration of maturation periods for sawdust-pig manure composts, leaf lettuces were applied with pig manure composts fermented for 15, 30, 45, 60, 75 days and 1 year (control) and cultivated in a plastic house with or without additional PE film tunnel. The changes in physiochemical properties of soil and leaf lettuce growth were measured. Shorter duration of maturation periods enhanced the generation of N $H_3$ gas from the composts and resulted in significant decrease in seed germination, growth and yield of leaf lettuce. Under with and without PE tunnel conditions the concentration of N $H_3$ from compost over 3.8 and 2.1 mg/100g composts, respectively induced growth reduction. In proportion to the increase of maturation duration saw-dust containing pig manure exhibited decrease in C/N ratio, N $H_4^{+}$-N, N $H_4^{+}$N $O_3^{-}$ ratio but increase in N $O_3^{-}$-N contents. In case of applying pig manure compost without PE film tunnel condition the minimum maturation period of pig manure composts for safe leaf growth was 60 days, while minimum 75 days of maturation was required when applied with PE film tunnel. tunnel.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.4
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• pp.380-383
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• 1998

For the evaluation of the quality of compost, the determination of C/N ratio is mandatory in Korea. Accordingly it is necessary to measure the total carbon content of compost for the quality control of composts. It is, however, not easy to measure the carbon content of compost. For practical purposes total carbon content of compost can be estimated from the total organic matter content, which is estimated by way of ignition loss. For this, it is necessary to establish the factor for conversion of organic matter into carbon. We studied the relationship between the organic matter content determined by ignition method and total carbon content measured by elemental analyzer using 160 compost sample collected from the markets. The relationship between the carbon content and organic matter in those composts was found to be "y(% carbon)=1.995+0.484%(% organic matter)"($r^2=0.943$). This result suggests that total carbon contents of composts can be estimated from the organic matter content.

• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.1
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• pp.31-42
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• 1999

To investigate the effects of the composts made of sewage sludges on the physico-chemical properties of soil and growth of paddy rice, the variations of chemical properties in soil, the contents of inorganic matters and heavy metals in plant tissues, the contents of heavy metals in brown rice, the growth response of paddy rice and grain yield were investigated. The results were summarized as follows : The contents of organic matters, N, available $P_2O_5$ and exchangeable K in soil were increased by application of the composts. The contents of N and available $P_2O_5$ in soil were remarkably decreased at the harvesting time in comparing with the 20th day after application of the composts. The contents of heavy metals in soil were increased very slightly by application of the com-post. At the harvesting time, the contents of N and K were not varied in all plant tissues at the plot of the compost in comparing with the plot of the NPK. The content of $P_2O_5$ in plant was increased by application of the composts. The contents of heavy metals in plant tissues and brown rice were not changed among the treatments. When the composts were applied to the pot at the rates of 1,000, 2,000, 4,000 and 6,000kg/10a with NPK, the numbers of grain yield were increased with 3, 18, 44 and 54% in comparing with NPK plot, respectively. Dry weight, the numbers of tillers and spikelet of the rice plant were increased by application of the composts.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.6
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• pp.313-320
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• 2005

Various by-product composts are applied in alpine farmland, and some of them generate many problems especially when they are not completely composted. The objective of this study was to investigate the physicochemical and spectroscopic properties of by-product composts used in Gangweon alpine uplands. Average organic matter content, C/N ratio and NaCl content in 3 species of registered composts were 33%, 13 and 0.8%, respectively, and the general quality were better than the guideline of by-product compost. Odor and contents of $NH_3$ and $CO_2$ in the registered composts were relatively lower than those in the unregistered composts. Among the 13 unregistered composts tested in this experiment, 3 species contained organic matter content less than 25%, 5 species had C/N ratio less than 10, and 8 species contained NaCl exceeded the acceptable level. Eight species in the unregistered composts contained more than 50% of water. Contents of heavy metals in both the registered and unregistered composts were lower than the acceptable level. In spectroscopic property analysis, registered composts were Band P types, and unregistered composts were Rp and P types.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.186-189
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• 2011

By surveying the 70 composting plants in Gyeonggi Province, the total commercial production of livestock faeces composts (LFCs) in 2008 was estimated to be about 480,000 Mg year-1 and they were manufactured mainly by using both mechanical mixer and bottom air blower. LFCs were composed mainly of chicken faeces 29.2%, pig+chicken faeces 23.1%, pig faeces 20.0%, livestock faeces+oil cake 12.3%, pig+chicken+cattle faeces 10.8% and pig+cattle faeces 4.6%. On the basis of the current official standard which was revised on March 2010, 11 composts out of surveyed 76 ones did not meet the LFCs quality standard (LQS) due to inadequate content of water (5), OM/N (1), NaCl (2) and Zn (3). The OM/N declined by adding chicken faeces and oil cake, while Ca content increased by the addition of chicken faeces and NaCl increased by adding cattle faeces.

• Korean Journal of Medicinal Crop Science
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• v.17 no.6
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• pp.415-420
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• 2009

This study was carried out to select economical byproduct composts as the substitute for the traditional organic fertilizer, Yacto, in the cultivation of ginseng seedlings, and to investigate the application method of a selected compost. Among tested byproduct composts, popped rice hull compost was the best substitute for Yacto, while the application of domestic animal manure composts resulted in red skinned roots of ginseng seedlings. Optimal mixing ratio of the popped rice hull compost with virgin soil (fine sand) were 3~4 : 1 in bulk, showing the same root yield compared to that of conventional seedbed soil. When the popped rice hull compost was lower than $1\;{\pm}\;0.1%$ in nitrogen content, the expeller cake of oil seed was added to seedbed soil to rise nitrogen content until $1\;{\pm}\;0.1%$.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.4
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• pp.527-533
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• 2011

Decomposition of compost applied to soils is affected basically by its biological stability; but, many other chemical properties of the compost may also influence compost organic-C mineralization. This study was conducted to investigate the principal substrate quality factors of composts that determine C mineralization of compost with similar stability degree (SD). Three composts samples with similar SD but different chemical properties such as pH, C/N, $K_2SO_4$-extractable C, and molar ratio of $NH_4^+$ to $NO_3^-$ were mixed with an acid loamy soil and $CO_2$ emission was monitored during the laboratory incubation for 100 days. Temporal pattern of cumulative compost organic-C mineralization expressed as % of total organic C ($C_{%\;TOC}$) followed double exponential first order kinetics model and the $C_{%\;TOC}$ ranged from 4.8 to 11.8% at the end of incubation. The pattern of C%TOC among the composts was not coincident with the SD pattern (40.1 to 58.6%) of the composts; e.g. compost with the lowest SD resulted in the least $C_{%\;TOC}$ and vice versa. This result indicates that SD of compost can not serve as a concrete predictor of compost mineralization as SD is subject not only to maturity of compost but also to characteristics of co-composting materials such as rice hull (low SD) and sawdust (high SD). Meanwhile, such pattern of $C_{%\;TOC}$ collaborated with pH, C/N, $K_2SO_4$-extractable C, and molar ratio of $NH_4^+$ to $NO_3^-$ of the composts that are regarded as chemical indices of the progress of composting. Therefore, for better prediction of compost mineralization in soils, it is necessary to consider both SD and other chemical indices (pH, C/N, and molar ratio of $NH_4^+$ to $NO_3^-$).

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.3
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• pp.33-40
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• 2014

This study were conducted to evaluate the N mineralization and nitrification rates and to estimate the losses of total carbon and nitrogen by runoff water in soils cooperated with organic composts and bio-char during corn cultivation. For the experiment, the soil texture used in this study was clay loam, and application rates of chemical fertilizer and bio-char were $230-107-190kg\;ha^{-1}$($N-P_2O_5-K_2O$) as recommended amount after soil test and 0.2% to soil weight. The soil samples were periodically taken at every 15 day intervals during the experimental periods. The treatments were consisted of cow compost, pig compost, swine digestate from aerobic digestion system, and their bio-char cooperation. For N mineralization and nitrification rates, it was shown that there were generally low in the soil cooperated with bio-char as compared to the only application plots of different organic composts except for 47 days after sowing. Also, they were observed to be highest in the application plot of swine digestate from aerobic digestion system. For loss of total carbon by run-off water, it was ranged from 1.5 to $3.0kg\;ha^{-1}$ in the different organic compost treatment plots. However, Loss of total carbon with bio-char could be reduced at $0.4kg\;ha^{-1}$ in PC treatment plot. Also, with application of bio-char, total nitrogen was estimated to be reduced at 4.2 (15.1%) and $3.8(11.8%)kg\;ha^{-1}$ in application plots of pig compost and swine aerobic digestate, respectively.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1623-1623
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• 2001

Composting is a biological method used to transform the organic waste into stable, humified organic amendments. Humification is indicated as the key factor in improving the quality of compost, because of the importance of humic substances to soil ecology, fertility and structure, and their beneficial effects on plant growth The compost constituents vary widely, however, the degree of maturity is very important factor in compost quality. So this experiment carried out to determine the rapid estimation of the quality in cattle, pig, chicken and waste composts using near infrared reflectance spectroscopy(NIRS). Near infrared reflectance spectra of composts was obtained by Infra Alyzer 500 scanning spectrophotometer at 2-nm intervals from 1100 to 2500nm. Multiple linear regression(MLR) or partial least square regression (PLSR) was used to evaluate a NIRS method for the rapid and nondestructive determination of humic acid contents in composts. The results summarized that NIR spectroscopy can be used as a routine testing method to determine quantitatively the humic acid content in the compost samples ondestructively. Especially, we supposed that absorbance around 2300nm is related to humic acid as a factor of compost maturity. However the NIR absorption approach is empirical, it actually requires many combinations of samples and data manipulations to obtain optimal prediction.

• Korean Journal of Environmental Agriculture
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• v.16 no.3
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• pp.220-226
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• 1997

To study the possibility of agricultural utilization of the municipal sewage and the industrial wastewater sludges, the chemical properties of soil, the growth response of corn plant and uptake of inorganic nutrients in plant tissues were investigated by application of the composts made of the sludges to the pots at the rate of 2,000kg/10a. The contents of organic matter, T-N, $P_2O_5$ and K in soil were increased by application of the composts. Each heavy metals contents in soil were increased very slightly by application of the composts. The fresh weights of corn plant were increased with $9{\sim}19%\;and\;60{\sim}79%$ at the plot of compost and NPK+composts in comparing with the plot of NPK, respectively. Uptake of N, $P_2O_5,\;K_2O$, CaO and MgO in stem and leaf of corn plant were increased by applications of the composts.