• Asian-Australasian Journal of Animal Sciences
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• v.12 no.7
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• pp.1162-1169
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• 1999

Modern livestock production facilities face both challenges and opportunities with respect to sustainable manure management practices. Nutrient recycling is constrained by the size of modern livestock operations, the low nutrient density of liquid manures, and the spatial and temporal variability of manure nutrient concentrations. These constraints can and must be addressed or farmers will be increasingly drawn to nutrient wasting strategies such as anaerobic lagoons, wetlands, and other systems designed to treat and discharge nutrients to the environment. Intentional discharge of nutrients is difficult to justify in a sustainable agricultural production system, since replacing those nutrients through chemical fertilization requires considerable expenditure of energy. In contrast, there are several currently viable technologies which provide the homogenization and stabilization needed to successfully compete against chemical fertilizers, including composting, pelletization, and anaerobic digestion. Some of these technologies, particularly anaerobic digestion and composting, also open up increased opportunities to market the energy and nutrients in manure to non-agricultural uses. Future advances in biotechnology are likely to demonstrate additional options to transform manure into fuels, chemicals, and other non-agricultural products.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.97-101
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• 1999

No-till direct seeding cultivation of rice has major advantages such as saving of labor and cost by eliminating tillage, preparation of seed bed and trans-planting procedure compared to the conventional transplanting cultivation. A field experiment was conducted to evaluate the effects of straw treatment and nitrogen levels on the rice growth in no-till direct-seeding cultivation. Rice straw, vetch straw, and the mixture of both of the straws were mulched on the surface of soil before seeding while 4 levels of nitrogen fertilizer, 0, 7, 9, and 11 kkg/10a respectively, were applied at 3 split times, 3-weeks after sowing, 5-weeks after sowing and the panicle initiation stage. Mulching of vetch straw significantly reduced seedling establishment of rice which may be attributed to low oxidation-reduction potential of soil by vetch mulching treatment. Vetch straw increased the concentration of soil ammonium leading to an extension of the greenish leaf to panicle initiation stage. Agronomic nitrogen use efficiency (AD $E_{N}$) in heavy-mixed straw mulching plots was lower than other treatments. Grain yield and AU $E_{N}$ in the vetch treatment were less affected by fertilized N levels. Conclusively, it is suggested that heavy straw mulching was not efficient for rice seedling establishment and nitrogen usage.e.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.102-105
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• 1999

Mineralization of organic N is an important factor in determining the appropriate rate of organic matter application to paddy fields. A kinetic analysis was conducted for nitrogen mineralization of rice, barley, Chinese milk Ovetch (Astragalus sinicus L.; MV) and narrow leaf vetch straw in paddy soil. Nitrogen immobilization occurred rapidly and its rate increased in straw with high C/N ratio. The amount of nitrogen mineralization was rapid in the first year of rice-vetch cropping system. The rate constant (K) depended on the C/N ratio of organic matter. Mineralization of straw increased at high temperature. The amount of available N increment resulted in fast mineralization of straw, especially in rice and barley straw. Chinese milk vetch had the greatest mineralization rate at all temperatures and fertilization levels followed by narrow-leaf vetch. However, rice and barley straws with high C/N ratio immobilized the soil N at the initial incubation duration. Chinese milk vetch or narrow leaf vetch was not effectively mineralized in mixed treatments with rice or barley straw. The mineralization rate of organic matter was mostly affected by the C/N ratio of straw and temperature of incubation. Organic matter with low C/N ratio should be recommended to avoid the immobilization of soil N and the increasing mineralization rate of straw.

• Reproductive and Developmental Biology
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• v.28 no.4
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• pp.235-240
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• 2004

In vitro maturation of denuded porcine immature oocytes can be enhanced by co-incubation with spermatozoa even before fertilization. This study was to determine whether the addition of spermatozoa into the culture medium could influence the nuclear maturation of porcine cumulus-enclosed germinal vesicle (GV) oocytes. Cumulus-oocyte complexes (COCs) were collected from follicles of 3- to 5-mm diameter. Porcine COCs were cultured in tissue culture medium containing spermatozoa. After 48 h culture, oocytes were examined for evidence of GV breakdown, metaphase I, anaphase-telophase I, and metaphase II. The proportion of oocytes reaching at metaphase II was significantly (P < 0.05) increased in the oocytes cultured in media containing spermatozoa compared to those in media without spermatozoa (52.3% vs 12.5%). No difference in the percentage of metaphase II was observed among the different periods of spermatozoa exposure and among the spermatozoa from different species. The proportion of oocytes reaching metaphase II was significantly different between high and low concentrations of spermatozoa. The present study suggests that manunalian spermatozoa contain a substance(s) that improves nuclear in vitro maturation of porcine cumulus-enclosed GV oocytes. Enhancing effect of spermatozoa for in vitro maturation of oocytes is a highly dose-dependent.

• Journal of Animal Environmental Science
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• v.20 no.2
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• pp.77-84
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• 2014

This study was conducted to investigate the bacterial capability to accumulate phosphorus during liquid composting process of pig slurry. Storage liquid compost and pig slurry were analyzed by using MALDI-TOF technique, which showed the colonies of Acinetobacter towneri and Bacillus licheniformis. In addition, bacterial colonies were isolated under high phosphoric acid conditions using X-phosphate MOPS medium with the addition of 2 mM $K_2HPO_4$. Microbial growth was observed in high and low phosphoric conditions due to the growth of bacterial diversities in the liquid fertilizer and slurry. The colonies isolated in the high phosphoric acid medium were uncultured bacterium clone and Acinetobacter sp. were identified by analysis of 16S rRNA gene sequences. Uncultured bacterium showed higher growth rate and excellent phosphorus ability then Acinetobacter sp.. In addition to Paenibacillus sp. AEY-1 isolated from pig slurry performed excellent phosphorus utilizing capability.

• Journal of the Korean Society of Tobacco Science
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• v.25 no.1
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• pp.27-33
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• 2003

This study was conducted to determine the changes of nitrogen compounds in lamina and midrib during the curing process with the different curing methods, such as priming and stalk-cut curing. After KB 108 burley tobacco was cultivated by the different fetilization levels such as standard and 20% higher, only the tips and leaf were harvested. Though the contents of total alkaloid and total nitrogen were similar in lamina, midrib showed a very low contents of those components by the different curing method and fertilization levels. The content of nitrate-nitrogen in lamina increased during a middle of curing process, and then these compound was decreased during an end of curing process by stalk-cut curing method. Nitrate-nitrogen contents in the lamina by the priming curing showed a high level caused by rapid drying process during an end of curing process. That component in midrib was 5-6 times higher than that of lamina. The contents of ammonia-nitrogen in the lamina and midrib were increased during a curing process. Though those amount in tips showed a similar by a different fetilization and curing method, midrib of stalk-cut curing showed a slow increasing during a curing process.

• The Korean Journal of Ecology
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• v.21 no.1
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• pp.15-26
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• 1998

This study was conducted to analyze arthropod community patterns in smallrice fields managed by different cultural methods [Conventional and Low Input Sustainable Agriculture(LISA)] in Suwon in 1995 and 1996. A half of nitrogen fertilizers and a quarter of pesticides were applied in the LISA field compared to in the conventional field. Total 15 orders and 43 families of arthropods were collected in two years. No differences were found in arthropod abundance and arthropod species composition between two differently practiced fields. The arthropod community was analyzed using guild categories. The arthropods were found in the order of 'pest(phytophag)>natural enemy>non-pest' in their densities. The pest species were mainly Homoptera and dominated by Delphacidae (Nilaparvata lugens Stal and Sogatella furcifera Horvath). They constituted > 80% of pest abundance. The spider was the most dominant group in the natural enemy and constituted > 90% of natural enemy abundance. Hunting spiders constituted > 60% of spider abundance and were dominated by Pirata subpiraticus Bos. et Str.(Lycosidae). Pachygnatha clerki Sundevall(Tetragnathidae), Gnathonarium dentatum Weider and Ummeliata angulituberis Oi(Erigonidae) were the dominant species in webbing spiders.

• Environmental Engineering Research
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• v.23 no.3
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• pp.271-281
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• 2018

To examine the feasibility of reuse of raw fishmeal wastewater, it was biodegraded by a microbial consortium in a $1-m^3$ reactor, and the final culture broth including mixed microbes was applied as biofertilizer to field cultivation of lettuce and Chinese cabbage. Moreover, economic analysis of the entire process was performed. A stable metabolism of organic matter degradation for 80 h with sufficient dissolved oxygen produced an amino acid content of 14.66 g per 100 g sample, along with increased cation and anion concentrations. The concentrations of N, P and K in the final culture broth were 2.26, 0.87 and 0.65%, respectively, while those of heavy metals were very low. In field cultivation of the two leafy vegetables, the biodegraded fishmeal wastewater showed better fertilizing ability than commercial fertilizers because of its high amino acid content. In addition, no external damage to leaves by the fertilization was observed. In economic analysis, the expected profitability from the practical reuse of raw fishmeal wastewater was estimated to be $491.68 per a single biodegradation, which corresponds to $25,567.36 per year. As a result, the complete reuse of fishmeal wastewater could be feasible and provide essential benefits.

• 한국환경농학회:학술대회논문집
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• 2011.07a
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• pp.188-195
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• 2011

Red lateritic soils are typically low in total organic carbon (TOC) and available phosphorus (AP) content and continuous fertilization is required to obtain desired crop yield. In this experiment, cattle manure in three forms (air-dried, composted and vermicomposted) were applied to red lateritic soil to study their effect on TOC and AP content of soil and probable mechanism of P-solubilization as affected by these treatments were also studied. Vermicompost was the most effective to solubilize insoluble P in red lateritic soil (Alfisols) as compared to other organic amendments (air-dried cattle manure and compost). The highest SPA in vermicompost-treated soil attributed to the comparatively higher concentration of all the three SPA isozymes in these soils. The maximum P-solubilization in these soils might be attributed to the highest SPA and presence of several organic acids like citric, lactic and oxalic acids in vermicompost-treated soils. Since, vermicompost application also increased TOC, mineralizable N and exchangeable K content of soil, vermicompost could be considered as the most rational organic amendment to improve chemical properties of red lateritic soils.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.1
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• pp.48-54
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• 2022

Parthenogenesis is maternally uniparental reproduction through the embryonic development of oocytes without fertilization. Artificial activation of mature oocytes could generate homozygous haploid embryos with the extrusion of the second polar body. However, the haploid embryos showed low embryo development in preimplantation embryos. In this study, we investigated whether the electronic fusion of the haploid embryos could enhance embryo development and ESC establishment in mice. Haploid embryos showed the developmental delay from 4-cell to the blastocyst stage. The haploid blastomeres of the 2-cell stage were fused electronically, resulting in that the fused embryos showed a significantly higher rate of blastocysts compared to non-fused haploid embryos (55% vs. 37%). Further, the embryonic stem cells (ESCs) derived from the fused embryos were confirmed to be diploid. The rate of ESC establishment in fused embryos was significantly higher compared to non-fused ones. Based on the results, we concluded that the electronic fusion of haploid embryos could be efficient to generate homozygous ESCs.