Abstract:The experiment of fertilizer N rate showed that the yield response of Rumex K\|1 hybrid dock to fertilizer N could be described by the model of linear plus plateau and nitrogen from fertilizer Ndff linearly increased with N application, but utilization varied from 32 11% to 42 78%,under N 3 level (600N kg·hm -2 ), recommended as optinum fertilization,it was 42 78% and nitrogen remained in root varied from 19 87% to 24 3%. Total absorption rate of fertilizer N by plant varied from 51 97% to 67 15%, soil residue N kept almost unchanged with mean value of 21 89%. N recovery rate didn‘t changed significantly until N 3 and loss rate varied from 9 40% to 25 93% with the same tendency but in reverse. Under split fertilization soil total N reached to equilibrium for each treatment and didn‘t change significantly with crop No, however, it would be affected by fertilizer N rate and its turnover rate varied from 4 67% to 9 39%.