Study on development of comprehensive measurement system for evaluating "the environmental fluxes"in farmland

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For creating sustainable agriculture system or peserving the regional environment, evaluation of physical and chemical fluxes (referred here as "the environmental fluxes"), which are sensitive to the environment related to farmland, is of a fundamental issue. In this research, systems to accurately and comprehensively the measure environmental fluxes were developed. They were aimed to reveal various mass flows in soil system and the farmland environment. There were mainly three achievements.1.Thermal and watery environment in soil system : Heat and water flows in soil system were observed in various scales, from columns (in the laboratory) to the field. The flows were also evaluated through numerical simulations, and physical factors which dominated these flows were considered. Furthermore, a new technique for measuring frozen and melted depths of soil using the TDR was developed. It was confirmed that this technique was very useful in the field, especially under thawing process.2.Agro … More climatology (Evapotranspiration) : Experiments and observation were conducted for measurement and evaluation of evapotranspiration. In the broccoli field, climatic factors were measured in short time interval with high accuracy. Then, evapotranspiration properties were derived employing the energy balance method. With this result, crop coefficients to different growing stages were determined. In the laboratory, a new method based on sensing acoustic emission was introduced to measure transpiration independently. The result was agreeable for wood plants.3.Hydrological environment at basin level : Flood runoff and its quality from upland fields and adjoining forest area were measured. Through the analysis on water quality of rainwater and runoff water, chemical fluxes such as runoff loads and mass balance in the basins were calculated. Then, with constructing runoff and water quality models, runoff components were calculated and compared. Inter-verification between both models was also carried out. Less