用^(15)N示踪技术研究高产小麦、玉米的施氮规律

STUDIES ON UTILIZATION OF NITROGEN BY WHEAT AND MAIZE WITH 15 N TRACER METHOD

利用稳定性同位素15N示踪技术 ,探索小麦、玉米在高N施肥下的N素营养规律。结果表明 :小麦、玉米对追加15N化肥的吸收利用率为 2 8 42 %～ 46 2 8% ,向籽粒运转量为 5 4 %～68% ,追施N的有效期可连续 3茬作物 ,累计利用率为 5 2 0 7%～ 60 39%。在较高土壤肥力基础上 ,小麦、玉米年产量达 1 5 0 0 0kg hm2 ,小麦最佳氮肥施量为 1 5 0～ 1 87 5kg hm2 ,玉米为 30 0～375kg hm2 。

The characteristics of nitrogen fertilizer on wheat and maize were investigated by 15 N tracer method. The results showed that the assimilation and transportation efficiency of available nitrogen is 28.42%～46.28%, 54%～68% of which is in grain. The effectiveness of applied nitrogen can sustain three crops. The accumulated utilizing rate is 52.07%～60.39%. In higher level of soil fertility, the yield of wheat, maize up to 15000 kg/hm 2, the best nitrogen fertilizer applying quantity is 150～187.5 kg/hm 2 for wheat and 300～375 kg/hm 2 for maize.