不同氮素施肥方法对纳塔栎容器苗生长及非结构性碳水化合物积累的影响

【目的】探究不同氮素施肥方式和不同施氮量对纳塔栎容器苗生长及非结构性碳水化合物积累的影响,揭示苗木需肥规律并确定最佳施肥方式与施氮量。【方法】以纳塔栎1年生容器苗为试验材料,设置平均施肥和指数施肥两种施肥方式,每种方式设置4个浓度梯度的施肥处理,对照组不施肥,施肥间隔为7 d,共施肥15次。施肥结束后进行苗高、地径的测量,并收获苗木将其烘干,测定生物量和非结构性碳水化合物含量。【结果】平均施肥和指数施肥均显著促进了纳塔栎1年生容器苗的生长,指数施肥效果整体优于平均施肥;随着施氮量的增加,苗高、地径、地上部分生物量、地下部分生物量以及总生物量均在指数施肥900 mg/株(Z900)处理下取得最大值97.90 cm、10.33 mm、12.21 g、26.74 g和38.95 g,是CK的1.53、1.15、1.75、2.47和2.19倍。施氮更多地促进生物量分配给纳塔栎容器苗的茎和叶;纳塔栎容器苗茎、叶、根的可溶性糖含量在各施氮处理组中均有提升,且指数施肥处理效果更优;施氮显著促进叶部淀粉积累,抑制根部淀粉累积。【结论】就纳塔栎容器苗而言,指数施肥效果优于平均施肥。Z900处理下,纳塔栎1年生容器苗的生长发育最好,为纳塔栎容器苗生长最佳施肥处理。

Effects of different nitrogen fertilization methods on growth and non-structure carbohydrate accumulation of Quercus nuttallii seedlings

【Objective】The effects of different fertilization methods and different nitrogen application rates on the growth and non-structure carbohydrate accumulation of Quercus nuttallii container seedlings were investigated in this study. This was done to reveal the fertilizer demand of Q. nuttallii seedlings so that optimal fertilization methods and nitrogen application rates could be determined.【Method】Two fertilization methods of average fertilization and exponential fertilization levels were set with one-year-old Q. nuttallii container seedlings as the experimental objects. Fertilization treatments along four concentration gradients were set for each method. The fertilization interval was 7 days and 15 rounds of fertilizer applications were applied. The seedling height and ground diameter were measured after fertilization. Seedling samples were harvested and dried to measure biomass, soluble sugar and starch contents at the end of the experiment.【Result】Both ave-rage fertilization and exponential fertilization significantly promoted the growth of one-year-old Q. nuttallii container seedlings, and the effect of exponential fertilization was better than that of average fertilization. With the increase in nitrogen application, seedling height, ground diameter, aboveground biomass, underground biomass and total biomass all reached the maximum values of 97.90 cm, 10.33 mm, 12.21 g, 26.74 g, and 38.95 g, respectively, under the treatment of Z900; which was 1.53, 1.15, 1.75, 2.47 and 2.19 times the values of CK, respectively. The application of nitrogen fertilizer assigned more biomass to the stems and leaves. Further, the soluble sugar content of each organ increased significantly in each fertilization group and the effect of exponential fertilization was better, whereas the starch content decreased significantly in the roots.【Conclusion】The exponential fertilization was found to be better than the traditional fertilization. The growth and development of one-year-old Quercus nuttallii container seedlings treated with Z900 were the most impressive, suggesting that this treatment is an ideal fertilization treatment for Quercus nuttallii container seedlings.