• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.526-537
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• 1993

The development of composting techniques is essential to the low input sustainable agriculture. This paper resents an evaluation of composting system, compost materials, aeration & temperature effects, compost maturity , and operational concerns for compost utilization. The composting of organic waste is markedly affected by the nature of the feedstock and the operational temperature employed for the process. These two major parameters are critically examined in this paper, with references to the decomposition of the organic waste. Future research should concentrate on the indications of stability and environmental problems.

• Journal of Animal Environmental Science
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• v.15 no.1
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• pp.59-68
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• 2009

This study investigated the evaluation of maturity, stability, nutrient and heavy metal from rotating drum composter of food waste amended with poultry manure composting inoculated with effective microorganisms(EM). Composting were performed for the first, drying reactor($15m^3$) 3 hours and the second, composting reactor($30m^3$) 24 hours, and parameters monitored this period included moisture content, NaCl, pH, electrical conductivity(EC), C/N ratio, organic matter(OM), nutrient content and heavy metal. Changes in compost temperature during composting were maintained constantly in the range of $60{\sim}80^{\circ}C$ using firewood boiler(450 MJ/h). We examined physicochemical parameters and heavy metals in order to assess their effectiveness as stability and maturity, nutrient and harmful indicators such as seed germination rate<60%, potassium 1>%, dm and NaCl>1%, dm at the end of the final compost. The finished compost obtained after decomposition phase at the end of the 2nd composter could not be utilized for land improvement or reclamation.

• Environmental Engineering Research
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• v.20 no.3
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• pp.254-259
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• 2015

In this study, the characteristics as well as the maturity and stability of chicken manure collected from nine chicken farms in South Korea during the summer and winter seasons of 2014 are evaluated. The physicochemical parameter values of the manure, such as BOD, $NO_3-N$ and $PO_4-P$ etc. were determined using the Korea Standard test Method, HPLC, and APHA standard methods. The results showed that the alkalinity content and COD concentration in winter chicken manure were higher than those of summer chicken manure. The moisture content of summer manure was positively correlated with almost all of the other parameters of the manure, whereas it was negatively correlated with almost all of the other parameters in the winter manure. According to the criterion of C/N ratio, chicken manure indicated good quality compost. However, composted chicken manure showed immature and unstable compost when considering the criteria of the $NH_4-N/NO_3-N$ ratio and $NH_4-N$ concentrations.

• 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 $NO_3^-$).

• Korean Journal of Environmental Agriculture
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• v.18 no.4
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• pp.378-383
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• 1999

Changes of the spectroscopic characteristics of the organic matter fractions and circular filter paper chromatograph were assessed for the bark and piggery manure composts during the composting. as an approach to base the criteria of the compost maturity evaluation. Contents of humic acid-C (HA-C) and fulvic acid-C (FA-C) in both bark and piggery manure composts were decreased as the composting got closer to maturity, but the ratios of HA-C/FA-C were increased. During the composting. ${\Delta}log$ K values were decreased, but RF values were increased. Humic acid of the mature bark compost after 120 days of composting was A-type, as compared to Rp-type for the raw bark and B-type for the immature compost. However. humic acid of the mature piggery manure composts after 40 days of composting was B-type, indicating the humification of the organic matter fractions continued at this stage. Circular filter paper chromatograph of the mature bark compost exhibited the regular sawteeth pattern at the edge, but that of the mature piggery manure showed an irregular sawteeth pattern. Results demonstrated that spectroscopic characteristics and circular filter paper chromatograph of the organic by-product composts might be employed for the compost stability assessment.

• Environmental Engineering Research
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• v.19 no.1
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• pp.47-57
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• 2014

The aim of this paper was to study the effect of five different waste combinations (C/N 15, C/N 20, C/N 25, C/N 30, and control) of sewage sludge coupled with sawdust and cattle manure in a pilot scale rotary drum reactor, during 20 days of the composting process. Our results showed that C/N 30 possesses a higher temperature regime with higher % reduction in moisture content, total organic carbon, soluble biochemical oxygen demand and chemical oxygen demand; and higher % gain in total nitrogen and phosphorus at the end of the composting period implying the total amount of biodegradable organic material is stabilized. In addition, $CO_2$ evolution and oxygen uptake rate decreased during the process, reflecting the stable behavior of the final compost. A Solvita maturity index of 8 indicated that the compost was stable and ready for usage as a soil conditioner. The results indicated that composting can be an alternate technology for the management of sewage sludge disposal.

• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.2
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• pp.73-82
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• 1999

To verify the usefulness of enzyme activity as a index for the stability or maturity of apple pomace composting. the succession of microbial populations using viable count procedure. and Vmax of ${\beta}$-glucosidase and cellobiohydrolase were measured. based on an increase in fluorescence as the nonfluorescent methylumbelliferyl substrates were enzymatically hydrolyzed, leading to the highly fluorescent methylumbelliferyl molecule 4-methylumbelliferone(MUF). The activities of these enzymes in the decomposition of carbohydrates were gradually decreased in the course of the time. Correlation between microbial population and enzyme activity was not significant with exception of fungi. and the fungi were represented in high density. This indicates that the fungi probably play a major role in composting of apple pomace.

• Korean Journal of Environmental Agriculture
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• v.18 no.4
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• pp.372-377
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• 1999

Objective of this research was to draw the basic criteria of the compost maturity evaluation, by assessing the stability of chemical and physical properties of the bark and piggery manure byproduct composts during the composting. Colors of the mature composts were black and dark brown for the bark and piggery manure by-product composts, respectively. Good earthy odor was detected for both by-product composts after approximately 40 days composting, by which odors of the original raw materials were disappeared. pH and EC of the mature bark: compost were stabilized at 6.5 and 1dS/m, respectively. The respective values for the piggery compost were stabilized at 7.2 and 6dS/m. Organic matter contents were decreased with time to be stabilized at about 60% at the end of composting. During composting, total N contents of the bark and piggery composts were maintained at $1.1{\sim}1.5%$, and $1.5{\sim}2.2%$, respectively. For both fertilizers, $NH_4-N$ contents were increased at the initial stage bur. decreased after the middle stages of decomposition, resulting in the increase of $NO_3-N$ contents. Total inorganic N contents were increased with time. C/N ratios of both mature composts were stabilized at $25{\sim}27$. CEC of the bark compost was increased logarithmically with time and that of mature compost was 87cmol(+)/㎏. CEC of the piggery manure compost was hyperbolic function with rime and reached at 70cmol(+)/㎏ at the mature stage. Crude fiber analysis indicated that relative contents of lignin were increased with composting by compensating for the decreases of cellulose and hemicellulose contents.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.2
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• pp.111-116
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• 1994

These studies were carried out to investigate the possibility on the agricultural utilization of lake sediment collected in the Daecheong Lake. Several parameters to estimate the degree of maturity of compost by windrow system were tested during a 50 day periods, and the results were as follows : During the composting of Daecheong Lake sediment, C/N ratio decreased gradually from 18.9 at the beginning to 13.1 at the final, while CEC increased from 33.5me/100g to 62.5me/100g. The temperature of lake sediment pile was the highest as $52^{\circ}C$ at 15th day and then decreased slowly until $30^{\circ}C{\sim}40^{\circ}C$ after 50 days. The results may be suggested that Daecheong Lake sediment compost reaches an acceptable level of stability after about 50 days. In order to know the effect of the Lake sediment and its compost on the growth of tomato(Lycopersicum esculentum M.), pot experiments were performed. The appiication of lake sediment(AS) itself, sediment organic fertilizer(SOF), and NPK mixed with sediment organic fertilizer(NSF) was more effective for tomato plant height, fresh and dry weight, and chlorphyll content than those of control treatment. Also, the lake sediment compost improved the physico-chemical properties of soil such as pH, total carbon, total nitrogen, available phosphorous and CEC.

• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.261-272
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• 2004

This study was conducted to investigate indices affecting composts maturity for swine manure compost produced in a commercial composting facility with air-forced from the bottom. The composting was made of swine manure mixed with puffing rice hull(6: 4) and turned by escalating agitator twice a day. Composting samples were collected periodically during a 45-d composting cycle at that system, showing that indices of Ammonium-N to Nitrate-N ratio were sensitive indicators of composting quality. Pile temperature maintained more than 62$^{\circ}C$ and water contents decreased about 20% for 25days of composting. A great variety and high numbers of aerobic thermophilic heterotropic microbes playing critical roles in stability of composts have been examined in the final composts, sbowing that they were detected $10^8$ to $10^{10}$ $CFUg^{-1}$ in mesophilic bacteria, $10^3$ - $10^4$ in fungi and $10^6$ - $10^8$ in actinomycetes, respectively. The results of this study for detennining a factor affecting compost stability evaluations based on composting steps were as follows; 1. Ammonium-N concentrations were highest at the beginning of composting, reaching approximately 421mg/kg. However Ammonium-N concentrations were lower during curing, reaching approximately l04mg/kg just after 45 day. The ratio between $NH_4-N$ and $NO_3-N$ was above II at the beginning of composting and less than 2 at the final step(45 day). 2. Seed germination Index was dependent upon the compost phytotoxicity and its nutrition. The phytotocity caused the GI to low during the period of active composting(till 25 days of composting time) depending on the value of the undiluted. After 25 days of composting time, the GI was dependent upon compost nutrition. The Gennination index of the final step was calculated at over 80 without regard to treatments. 3. E4: E6 ratio in humic acid of composts was correlatively decreased from 8.86 to 6.76 during the period of active composting. After 25 days of composting time, the E4: E6 was consistently decreased from 6.76 to 4.67($r^2$ of total composting period was 0.95). 4. Water soluble carbon had a tendency to increase from 0.54% to 0.78%during the period of active composting. After 25 days of composting time, it was consistently decreased from 0.78% to 0.42%. Water soluble nitrogen increased from 0.22% to 0.32% during the period of 15 days after initial composting while decreased from 0.32% to 0.21% after 15days of composting. In consequence, the correlation coefficient($r^2$) between water soluble carbon and water soluble nitrogen was 0.12 during the period of active composting mule was 0.50 after 25 days of composting time