Abstract:
Studies on nitrogen movement and nitrogen use efficiency of 15N-labelled urea (referred to as NUE hereafter) play an crucial role in the young stage of rubber trees (Hevea brasiliensis). Appropriate nitrogen application rates can significantly contribute to foster the development of the plants, hence shorten the premature stage of the rubber trees. The 15N-labeled urea (15N abundance was 10.16%) was applied at three different rates of 1, 2, and 3 gN/pot on one-year-old ‘PB260’ rubber trees. The results showed that the 15N absorbed in all plant parts such as leaves, stems, and roots increased gradually by time, and was highest at 60 days after treatment (DAT), and then decreased at 90 DAT. The NUE in leaves was much higher than that in either roots or stems in all treatments. The highest NUE (38.46%) was obtained at 60 DAT when PB260 was treated with the rate of 1 gN/pot.
Keywords:
15N, PB260, rubber tree, urea use efficiency