A Serial research the use of N-urea in tea plants in Indonesia has been conducted frJm 1982-1985. The Nurea was detected in tea plants of young stage and in the soils (AndoBol, Regosol, Latosol, and Podzolik). The methods used in the researches were the conventional measurements for N losses in the from of a gas and of solution, and a tracer technique for naff in the soil profiles, in the whole plant part of young stage, and in the pluckable leaves of production stage. The conclusions of the researches are as follows: (1). In tea soils which have slightly acid reactions and rather high organic matter content, fertilizations with urea did not undergo too much losa due to volatilization and leaching Most of N-urea was lost as solution by run off when it was applied by broadcasting or were still remained in the soil profiles. (2). The Ndff for young unproductive tea plant was very much influenced by the prillling effect and soil characteristic which enhance the better growth of roots. The condition in which tea plant roots are growing vigorously, the competition of N-use in the soils is won by against plant soil microorganisms. (3). Ndff in the tea plants of early productive stage has been distributed about 70 ~ in leaf part and about 30 ~ in wooden part. (4). Time interval between two succassions of the fertilizer gift on productive tea plants using urea is better done at every 2,5 - 3 months. (5). The Ndff of tea plants of 6 - 15 years old has bean characterized by strongest uptake and slightest dilution effect.Zuhdi Sri Wibowo*Pusat Penelitian Perkebunan, Gambung
