水氮耦合对苹果幼树生长及^(15)N吸收利用的影响

Influence of Water-Nitrogen Coupling on Growth and ^(15)N Absorption and Utilization of Apple Saplings

以两年生红富士/平邑甜茶为试材,采用15N同位素标记示踪法,在滴灌施氮条件下研究3个氮水平与3个水量对苹果幼树生长及15N吸收、利用的影响。结果表明:随着氮肥及水量的增加,苹果植株新稍长度、干物质总量、植株15N吸收量均显著提高,高水高氮(W3N3)处理苹果植株新稍长度、干物质总量、植株15N吸收量最高,分别是77.98 cm、62.59 g、14.06 mg,低水低氮(W1N1)处理最低,分别为21.40 cm、35.29 g、3.55 mg。根系活力、叶绿素含量、植株各器官Ndff随着水、氮量增加而显著提高。15N利用率随着水量的增加而显著提高,随着氮量的增加而显著降低,W3N1处理最高,为20.0032%,W1N3处理最低,为9.0382%。

The effects of three nitrogen levels and three water levels under drip irrigation on the growth and 15N absorption and utilization of apple saplings were studied in field using 15N -labeled tracer method and with 2 -year -old Red Fuji/Malus hupenensis as materials. The results showed that the shoot length, total dry matter quantity and l5 N absorption increased significantly with the increase of nitrogen fertilizer and water a- mount; and they were the highest under W3N3 treatment as 77.98 cm, 62.59 g, and 14.06 mg respectively, while the lowest under W1N1 treatment as 21.40 cm, 35.29 g and 3.55 mg respectively. The root activity, chlorophyll content and Ndff in organs increased significantly with the increase of nitrogen fertilizer and water amount. The use rate of 15N increased significantly with the increase of water amount but decreased significant- ly with the increase of nitrogen fertilizer rate. The 15N use rate was the highest as 20. 0032% under W3N1 treatment, but was the lowest as 9. 0382% under W1N3 treatment.