• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 1998.10a
• /
• pp.473-478
• /
• 1998

Dead animals amended with agricultural rersidues are utilized ai a compost to promote soil fertility and reduce environmental pollution by traditional methods of livestock mortalities. The full-scale bin composting swine mortality in roofed system with three amendments was very successful in reaching sufficient temperature above 55$^{\circ}C$ long enough for pathogen kill. The average temperature of tile compost material in dead swine amended with corn stover increased rapidly to 64$^{\circ}C$ on the 2nd day after primary composting and dropped to near ambient temperature on the 140th day of composting. The composting temperature of corn stover and wheat straw is more efficient for swine carcass composting than that of sawdust.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.3
• /
• pp.294-301
• /
• 2022

In our greenhouse experiment, soil heat treatment groups (50, 80, and 121℃) significantly promoted growth and disease suppression of Panax notoginseng in consecutively cultivated soil (CCS) samples (p < 0.01), and 80℃ worked better than 50℃ and 121℃ (p < 0.01). Furthermore, we found that heat treatment at 80℃ changes the microbial diversity in CCS, and the inhibition ratios of culturable microorganisms, such as fungi and actinomycetes, were nearly 100%. However, the heat-tolerant bacterial community was preserved. The 16S rRNA gene and internal transcribed spacer (ITS) sequencing analyses indicated that the soil heat treatment had a greater effect on the Chao1 index and Shannon's diversity index of bacteria than fungi, and the relative abundances of Firmicutes and Proteobacteria were significantly higher than without heating (80 and 121℃, p < 0.05). Soil probiotic bacteria, such as Bacillus (67%), Sporosarcina (9%), Paenibacillus (6%), Paenisporosarcina (6%), and Cohnella (4%), remained in the soil after the 80℃ and 121℃ heat treatments. Although steam increased the relative abundances of most of the heat-tolerant microbes before sowing, richness and diversity gradually recovered to the level of CCS, regardless of fungi or bacteria, after replanting. Thus, we added heat-tolerant microbes (such as Bacillus) after steaming, which reduced the relative abundance of pathogens, recruited antagonistic bacteria, and provided a long-term protective effect compared to the steaming and Bacillus alone (p < 0.05). Taken together, the current study provides novel insight into sustainable agriculture in a consecutively cultivated system.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.47 no.5
• /
• pp.15-22
• /
• 2015

The crop production technologies keep in improving and the cultivation becomes more standardization owing to the significant developments of various agricultural materials. The artificial soil and base system for root could be one of the major technologies for the modern cultivation especially for controlled horticulture. Although the perlite, cocopeat, and peat moss are the major components of the artificial soil and are broadly used for various application, there is a great need for the new alternative materials for overcoming the low nutrition and the possible shortage of raw materials. In this study, the application of oil palm EFB fiber as an alternative materials for artificial soil especially for the seeding pad components was evaluated. The changes in the structural properties and the functional properties such as moisture holding properties were compared by laboratory produced seeding pads with different mixture of oil palm EFB fiber. The addition of fibrillated EFB fiber resulted in the significant increase in durability of the seeding pad, which showed the possible application of EFB fiber to the seeding pad instead of the wood fiber (UBKP). The moisture holding properties and the germination condition characteristics of the EFB fiber showed the slight less than those of the cocopeat, which require more sophisticated study for improving the functional properties of seeding pad made of the EFB fiber.

• Korean Journal of Agricultural Science
• /
• v.11 no.2
• /
• pp.264-269
• /
• 1984

The single edged blade was efficient to reduce tilling torque requirement than the double edged blade as previous reported study. This study was carried out to find reducing effects of tilling torque requirement of single edged blade comparing to double edged one in according to wearing by tilling operation. The single and double edged rotary blades were attached on same rotary shaft, and tilling operation was done in hard glass land. The wearing weights of the blade were checked out each 3 hrs tilling operation, at same time, the tilling toruqe requirements were measured with soil bin system in laboratory. The results of the study were summarized as follows: 1. The edged blade shape was not changed during the tilling operation of the rotary blade. The single edged blade was saved 5-10% in the maximum tilling torque and 3-15% in the mean tilling torque than the double edged blade for total durable period. 2. Generally, the tilling torques according to operation were decreased until original shape was maintained, but it was increased after 12 hrs tilling operation, and the tip shape of rotary blade was changed seriously. It is noted that the tip shape of the rotary blade is another factor affecting tilling torque, it should be desirable to study on the rotary blade tip shape to reduce tilling torque requirement after changing its original shape with wearing.

• The Korean Journal of Pesticide Science
• /
• v.9 no.1
• /
• pp.60-69
• /
• 2005

The herbicide molinate has been detected with high frequency in the main river during the growing season in Korea. To elucidate the exposure of molinate in agricultural environment, the persistence and the degradation characteristics of molinate were investigated in paddy ecosystems. The half-lives of molinate were 4.1 days with soil aquatic system, and 4.2 days in only aquatic system. Initial dissipation rate of molinate in water was greater with soil aquatic system than that of only aquatic system. Photolysis of molinate was occurred about 31.0% of molinate treated in pure water, when irradiated at 5,530 $J/cm^2$ by the xenon lamp, but its hydrolysis was stable. For the accelerated photolysis of molinate in aqueous solution, several photosensitizers were screened, showing that the hydroperoxide($H_2O_2$) and acetone were prominent among the chemical tested. When hydroperoxide and zinkoxide(ZnO) were used as photosensitizer, their photolysis were accelerated greater than 98% and 58% in aqueous solution, respectively. Elution rate of molinate as granular formulations in aqueous system was more than 90% in 30 hour at $35^{\circ}C$. Molinate concentration pattern in paddy water was rapidly decrease from treatment till 7 days in paddy rice field and its half-lives were 3.7 days($Y=1.9258{\times}e^{-0.1865X}$(r=-0.9402)).

• Journal of the Korean Geotechnical Society
• /
• v.24 no.5
• /
• pp.99-106
• /
• 2008

This study is concernsed with the effect of a chimney drainage system installed at the back of reinforced soil block on preventing the pore water pressure development. A series of finite-element analyses based on transient seepage analysis were performed for a number of cases with different patterns of the chimney drainage system. The results were thoroughly analyzed to get insight into the mechanism of pore water pressure reduction effect of the chimney drainage system. It is shown that a vertical drainage system installed at the back of reinforced zone can be an effective means of maintaining the wall stability during rainfall by preventing pore pressure increase in the reinforced as well as the backfill zones. Also shown is that the optimum height of the chimney drain is 50% of the wall height. Practical implications of the findings were discussed.

• Journal of Microbiology and Biotechnology
• /
• v.13 no.3
• /
• pp.463-468
• /
• 2003

Polychlorinated biphenyl are toxic pollutants and their degradation is quite slow in the environment. Recently, interest if bioremediation using PCB-degrading bacteria has increaset,. In a previous report, plant terpenes (p-cymene, (S)-(-)-limonene, ${\alpha}-pynene$, and ${\alpha}-terpinene$) have been found to be utilized by a PCB degrader and to induce the biphenyl dioxygenase gene in pure culture. In this study, Pseudomonas pseudoalcaligenes KF707, a PCB-degrading Gram-negative soil bacterium, was used to determine whether the terpene stimulation of PCB degrader occurred in the natural environment. First, P. pseudoalcaligenes KF707 was genetically tagged using a transposon with gfp (green fluorescent protein) as a reporter gone. The population dynamics of P. pseudoalcaligenes KF707 harboring gfp gene in a PCB-contaminated environment was examined with or without terpenoids added to the microcosm. About 10-100-fold increase was found in the population of PCB degraders when terpene was added, compared with control (non-terpenes samples and biphenyl added samples). It was proposed that the gfp-monitoring system is very useful and terpenes enhance the survivability of PCB degraders in PCB-contaminated environments.

• Korean Journal of Weed Science
• /
• v.30 no.3
• /
• pp.252-257
• /
• 2010

The experiments were carried out to develop ecological weed control system in wheat field of rice-wheat cropping system. The results were, depression effect on water foxtail by wheat seeding method decreased the seeding after doing soil rotary by 85% compared with the no practices. The occurrence of Water foxtail was 40 piece $m^{-2}$ on October 16, 29 piece $m^{-2}$ on October 26, and 4 piece $m^{-2}$ when surveying based on the standard of seeding the wheat at 15kg $ha^{-1}$ which decreased as the seeding time got later. According to the wheat seeding quantity 29 piece $m^{-2}$ occurred at 150kg $ha^{-1}$, and 8-11 piece $m^{-2}$ decreasingly at more than 200 kg $ha^{-1}$ of wheat seedlings based on seeding on October 26. As a result of summarizing the above results, crushing the soil by use of rotary before seeding wheat against the end of October, and seeding by increasing the seedling quantity (200 kg $ha^{-1}$) it is judged that the competition damage by weeds including water foxtail can be reduced without any use of herbicide.

• Journal of Microbiology and Biotechnology
• /
• v.12 no.3
• /
• pp.476-482
• /
• 2002

Methanol dehydrogenase (MDH) and c-type cytochromes from marine methanol-oxidizing bacterium, Methylophaga sp. MP, were purified and characterized. The native MDH had a molecular mass of 148 kDa and its isoelectric point was 5.5. Two c-type cytochromes, $c_L\;and\;c_H$, were found, and their isoelectric points were 3.4 and 8.0, respectively. The purified MDH had higher thermal stability than that of the other soil methylotrophic bacteria. The electron flow rate from MDH to cytochrome $c_L$was higher than that from MDH to cytochrome $c_H$, indicating that the physiological primary electron acceptor for MDH is cytochrome $c_L$. The electron transfer from MDH to phenazine ethosulfate (PES, artificial electron acceptor) in the two dye (PES/DCPIP)-linked assay system was not inhibited by NaCl, whereas the electron flow from MDH to cytochrome $c_L$ in the cytochrome/DCPIP-linked assay system was suppressed significantly by NaCl. Metal chelating agents such as EDTA showed the same effects on the MDH activity.

• Korean Journal of Agricultural Science
• /
• v.46 no.4
• /
• pp.781-790
• /
• 2019

Changes in the physical and chemical properties of soil materials during the nursing process have a great influence on the quality of containerized seedlings and on growth and survival after planting. In this study, the effect of biomaterials and their mixed ratios on the growth of Zelkova serrata seedlings in a containerized seedling production system was investigated. Mushroom sawdust, pine bark, and carbonized rice husk were used as biomaterials. The mixed ratios were 10% and 20% volume ratio of the growing medium volume, including the untreated controls. There was no significant difference in the height growth of the Zelkova serrata seedlings according to the biomaterials. The root collar diameter was the highest with the 20% carbonized rice husk and the lowest with the mushroom sawdust. The difference between the highest quality index and the lowest quality index was 30% in the order of the carbonized rice husk, pine bark, control, and mushroom sawdust, but there was no statistical significance. In this study, if the growing medium mixed with biomaterials does not reduce the seedling growth compared with the control, it is considered that the biomaterial can replace a part of the growing media. Therefore, the results show that some of the growing media can be replaced with carbonized rice husk or pine bark when producing Zelkova serrata seedlings.