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Nitrate loads in soil and water environments surrounding a Reed Canarygrass field amended with dairy cattle manure were assessed to provide proper management practices of animal waste application to agricultural fields. Soil in the field was Andisol. Water movement and nitrate transport in the soil were measured every 15 minutes with time domain reflectometry (TDR). Water quality of surface runoff and groundwater was frequently analyzed in the laboratory. Nitrate was transported from the soil surface into the soil profile by a downward water flux that occurred with the first rainfall event after manure was applied at the soil surface. Although there was evidence of water flux from the soil surface to the groundwater table about 2.5 m below the surface, the nitrate load deeper than about 0.8 m was very small and not significant. Sixteen days after manure application, the nitrate load in the upper 0.6 m soil layer decreased to the level of load prior to the application. Nitrate concentration in groundwater in the field and in nearby river water experienced insignificant fluctuations in the four months prior to and two months following the manure applications. Therefore, it was concluded that the current management practice did not adversely affect water quality in the surrounding environments. The upper soil layer between the surface and 0.8 m deep worked as a filter for nitrate in this field. Further study is needed to investigate the production of other nitrogen forms such as nitrous oxide, a greenhouse gas, through denitrification and nitrification of the manure applied.