氮肥水平对鲁梅克斯K-1杂交酸模氮素利用和氮素平衡的影响

EFFECT OF RERTILIZER N RATE ON NITROGEN UTILIZATION AND BALANCE OF RUMEX K-1 HYBRID DOCK

鲁梅克斯K 1杂交酸模对氮素的吸收与施氮量的关系可用线性加平台模型描述。植株氮素来自肥料氮的比例Ndff随施氮线性增加 ,但利用率随施氮量先上升后下降 ,变化范围从 32 1 1 %～ 42 78% ,在推荐施氮N3(6 0 0Nkg·hm- 2 )水平下为42 78%。根对肥料氮的截留率与植株利用率的趋势相似 ,在 1 9 87%～ 2 4 37%范围变化 ,植株吸收率在 51 97%～ 6 7 1 5%范围变化。肥料氮的土壤残留率基本不变 ,平均为 2 1 89%。氮肥回收率开始时随施氮无显著变化 ,N3处理后迅速下降 ,损失率趋势与之相同 ,但方向相反 ,在 9 40 %～ 2 5 93%范围变化。在分茬施肥的模式下 ,不同施氮下的土壤全氮不随茬次显著变化 ,但施氮对土壤全氮水平有显著影响 ,土壤全氮的全年周转率随施氮在范围 4 6 7%～ 9

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%.