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Rice Yield Response to Biochar Application Under Different Water Managements Practices
정원교 한국토양비료학회 2012 한국토양비료학회지 Vol.45 No.1
Increasing rice grain yield is critical for feeding rapid increasing of Asian population. However, global warming effect may be negative for sustainable rice production. Therefore it is essential to develop technologies not only for increasing grain yield but also for reducing global warming effect. Biochar, which is carbonized biomass, has a great potential of carbon sequestration and soil quality improvement, which can contribute grain yield increasing. In this study, rice yield responses to biochar application on the rice cropping system were evaluated with field experiments under different water management practices at the research farm of the University of Missouri-Columbia Delta Research Center, Portageville, MO. Biochar (i.e., 4 Mg ha-1) was produced using field scale pyrolyzer and incorporated into the field 4 months prior to planting. Rice was grown under three different water management practices. Result showed that no significant yield difference was found in the biochar application plots compared to rice hull and control plots from the 2 years field study at the very fertile soil. However, rainfed management results in severe reduction of yield. Research concludes that the biochar application does not significantly influence on rice yield increasing especially for very fertile soils.
정원교 한국토양비료학회 2007 한국토양비료학회지 Vol.40 No.1
Global climate change is the crucial environmental issue of the twenty first century for all of the countries in the world (Intergovernmental Panel on Climate Change [IPCC], 2001). Temperature change has already been reported from the many observations (Lal, 2004). IPCC (2001) reported that global temperature increased 0.6oC during the twentieth century. The carbon cycle is involved in the cause and remediation of the global climate change (Scholes and Noble, 2001). Carbon dioxide concentration in atmosphere has rapidly increased for the last century mainly because of fast increasing in fossil fuel consumption (Lal, 2004). There is no absolute solution to address global warming problem except stopping use of fossil fuel. Unfortunately, current technology doesn’t provide enough alternative energy source, that can replace the fossil fuels. Reduced consumption of fossil fuels may be the long‐term goal for mitigating global climate change and other solutions could be temporary or short‐term (Lal et al., 2004). Prior to industrial development, deforestation and land cultivation were the main sources of carbon dioxide (CO2) emission (West and Post, 2002). Numerous studies found that plant and soil could be either sources or storages of carbon dioxide in atmosphere (Robert, 2006). Kyoto protocol addressed that carbon sequestration in agricultural soils was accepted to store carbon into the soils (Lal, 2004). What does carbon plays in the soils? Organic carbon originally comes from plant residues and returning capacity is depending on moisture, temperature, and nutrients. Micro‐organism decomposes fresh organic materials and emits carbon dioxide into atmosphere through respiration (Bernoux, 2006). In natural ecosystem, atmospheric carbon dioxide concentration and soil organic carbon may sustain a natural equilibrium without any external impacts.
정원교,박상성,신영근,장동식 대한산업공학회 2007 산업공학 Vol.20 No.3
Because the coins of about 920 billion are hoarded during these ten years, the national treasury of about 35 billion wons is wasted in minting coins every year. In this paper we promote to revitalize the circulation of coins through the connection with the financial world. Firstly embedded software that is contained in the coin banking ATM is developed. Then we developed new business process model that does customer spend coins efficiently in online through this system. The system constructed in this paper can contribute to the public interest and the marketability of the nation because of reducing waste of the national treasury and improving utilization and negotiability of coins.
논토양경운방법이 토양입자크기별 토양유기탄소의 함량에 미치는 영향
정원교,한희석 한국토양비료학회 2007 한국토양비료학회지 Vol.40 No.4
Quantifying soil organic carbon (SOC) has long been considered to improve our understanding of soil productivity, soil carbon dynamics, and soil quality. And also SOC could contribute as a major soil management factor for prescribing fertilizers and controlling of soil erosion and runoff. Reducing tillage intensity has been recommended to sequester SOC into soil. On the other hand, determination of traditional SOC could barely identify the tillage practices effect. Physical soil fractionation has been reported to improve interpretation of soil tillage practices impact on SOC dynamics. However, most of these researches were focused onupland soils and few researches were conducted on paddy soils. Therefore, the objective of this research was to evaluate paddy soil tillage impact on SOC by physical soil fractionation. Soils were sampled in conventional-tillage (CT), partial-tillage (PT), no-tillage (NT), and shallow-tillage (ST)plots at the National Institute of Crop Science research farm. Samples were obtained at the three sampling depth with 7.5-cm increment from the surface and were sieved with 0.25- and 0.053-mm screen. Soil organic carbon was determined by wet combustion method. Significant difference of SOC contentwas found among sampling soil depth and soil particle size. SOC content tended to increase at the ST plot with increasing size of soil particle fraction. We conclude that quantifying soil organic carbon by physical soil particle fractionation could improve understanding of SOC dynamics by soil tillage practices.