以15N研究烤烟对饼肥和秸秆肥中氮素的吸收与分配

应用^15N稳定性同位素示踪技术，研究了^15N-菜籽饼肥和^15N-秸秆肥与无机肥不同配比和不同施肥方法等不同处理中烤烟对饼肥和秸秆肥中氮素的吸收利用效果。结果表明：（1）烤烟各器官来自肥料的氮（NDFF％）随着饼肥和秸秆肥施用量的增加而增加，且有顶权〉上部叶〉中部叶〉下部叶〉茎〉根的趋势；（2）烤烟对饼肥中氮素利用率显著高于秸秆肥，饼肥组合中在下部叶成熟时达到高峰，以后稍有降低，且以25％饼肥＋75％硝铵全基施利用率最高，达到40．07％。秸秆肥组合中以25％秸秆肥＋75％全基施利用率最高，且各处理烟株整个生育期利用率持续上升，不利于上部烟叶落黄成熟；（3）秸秆肥处理的回收率较饼肥处理的普遍要高，都在90％左右，土壤残留率高，不利于前期烟草的生长。饼肥处理中以25％饼肥＋75％硝铵全基施的回收率较高，达到81．80％；（4）土壤“AN”值以25％饼肥＋75％硝铵基追各半和25％秸秆肥＋75％硝铵基追各半最高，说明土壤有机肥施用量不宜偏高，一般以保持中等施肥水平较好。

Flue-cured Tobacco's Absorption and Distribution of Nitrogen from Oil Cake Fertilizer and Stalk Fertilizer by 15N

The experiment was conducted on the absorption and utilization effects of nitrogen from rape cake fertilizer,straw fertilizer and chemical fertilizer in different rates and with different application methods by using ~(15)N stabilization isotopic tracing.The results showed as follows:(1) The NDFF% in tobacco plants increased as the applied amount of cake fertilizer and straw fertilizer went up,and followed the rule of tip>upper leaf>middle leaf>lower leaf>stalk>root;(2) Nitrogen utilization rate for flue-cured tobacco from cake fertilizer was obvious higher than that from straw fertilizer,which rose to quite high pinnacle at the lower leaf maturity stage,fell a little in the late stages,and the highest nitrogen utilization rate was 40.07%,which was reached when the flue-cured tobacco was treated with 25% cake fertilizer + 75% chemical fertilizer basal dressed.The highest nitrogen utilization rate in straw fertilizer combination was reached when it was treated with 25% cake fertilizer + 75% chemical fertilizer basal dressed,but the utilization rate would rise from group period to upper leaf maturity period,which is bad to the maturity of upper leaf.(3) The reclamation rate of nitrogen in straw fertilizer was higher than that in rape cake fertilizer,which was around 90%.The rudimental rate was high,which was disadvantageous to the growth of tobacco at young stage.The reclamation rate of nitrogen in rape cake fertilizer was the highest with the treatment of 25% cake fertilizer +75% chemical fertilizer full basal dressed,which reached 81.80%.(4)The A_(N)value of soil was the highest both with the treatments of 25% cake fertilizer+75% chemical fertilizer of 50% basal dressing and 50% top dressing and with the treatment of 25% straw fertilizer +75% chemical fertilizer of 50 basal dressing and 50% top dressing.That is to say,the fertilizer applied quantity on the high side is not suitable,which the optimal fertilizer applied quantity is middle quantity.