To investigate the influence of chemical fertilizers on groundwatear and surfacewater neighboring tea plantations in central Shizuoka prefecture, a time series of chemical compositions and nitrogen isotopic ratios within local wells, springs, rivers and ponds were studied.The pH of spring and pond water in some areas maintained basic acidity with neither any noticeable changes in nitrogen isotopic ratios nor any disappearance of nitrate within the ponds and low concentrations of chlorophyll and phosphorus.Therefore, the activities of photosynthesis in the ponds of this area were very low due to low concentrations of phosphorus. However, the pH of spring water in the other areas maintained basic neutrality to alkali with high concentrations of C2+a and SO2-4 and low concentrations of NO-3 because of soil and fertilizer improvement.Concentrations of Al, Co, Ni, Zn and Mn ions in the groundwater and surface water increased with the decrease of pH values.Then, soil and fertilizer improvemenit si important.
