<sup>15</sup>N Tracer-based Analysis on Nitrogen Utilization Laws of Rice Under Different Irrigation Modes

In order to promote the efficient and coordinated utilization of water nitrogen in rice, the  15 N missing technology experiment was adopted study effects application rate (N 0 , 160 200 240 ) irrigation mode (Wet-dry alternation, conventional irrigation) on absorption, transport, residue, loss super rice. The results showed that with increase rate, accumulation fertilizer total rice plants at different growth stages, various organs mature stage increased significantly, per panicle highest, reaching 67.20%~69.02%. transport amount from sources vegetative comparison as follows: leaf > stem root; After full heading, its contribution grain spike but residual soil a downward trend, significantly. Dry-wet alternate treatment can periods, improve use efficiency yield certain extent. This summarized laws utilization, residue under conditions conditions, which provided theoretical basis for cultivation