抄録
A large amount of nitrogen fertilizer has been applied in tea cultivation to produce the new shoots contained much amino acids. However the recovery rates of nitrogen by tea plants are comparatively low, and excessive application of nitrogen bring on the increase in nitrate concentration of the groundwater. It could be essential for the distributed region of root system magnification in tea plants by the the soil improvement before planting in tea gardens to increase the recovery rates of applied nitrogen. We estimated that the nitrate leaching rates from tea gardens was suppressed by the use of coated fertilizer and the application of fertilizer into surface soil by injection method.
