巨量元素缺乏對尾葉桉苗木生長及營養狀況之影響

Effect of Macronutrient Deficiency an the Growth and Nutrient Status of Eucalyptus urophylla Seedlings

程煒兒(Wei-Er Cheng) ； 洪富文(Fu-Wen Horng)

《林業試驗所研究報告季刊》 7卷2期 (1992/06) Pp. 111-120

https://doi.org/10.7075/BTFRI.199206.0111

摘要

本研究旨在探討尾葉桉苗木缺乏巨量元素所呈現之症狀，以及對其生長和營養狀況之影響。供為研判該樹種養分缺乏之依據。並提供施肥參考。苗木培育時間計31週，其中俊18週特以缺乏單一養分元素之營養液培育苗木。結果顯示：(1)缺氮老葉先黃化，嚴重時變紅色，較正常植株矮小；缺磷葉脈間呈藍紫色斑塊；缺鉀下層葉先黃化，上有褐色斑點，葉尖及葉綠呈褐色；缺鈣頂端幼葉出現黑褐色斑點；缺鎂葉脈間黃化，下眉葉易脫落，(2)巨量元素缺乏對尾葉桉苗木影響至钜者為氮素，其全株乾重僅為完全營養液苗木之10.5%；其次是缺磷56.3%；缺鎂82.7%；缺鈣91%；缺鉀96.3%，故氮素為尾葉桉生長之決定性養分。(3)培育於完全營養液尾葉桉苗木葉片中各養分濃度間之比例，可作為診斷其苗木及生長介質營養狀況之依據；又，所吸取之各養分量，以及各養分元素間之比例(N：P：K：Ca：Mg=4.4：2：40：29：1)可供為尾葉桉苗木植於不同生長介質時養分供應之參考。

關鍵字

尾葉桉 ； 巨量元素缺乏 ； 營養狀況

並列摘要

The aim of this study was to develop a reference for the diagnosis of macronutrient deficiency and f or optimum fertilization of Eacalyprus urophylla seedlings in nursery or plantations. The seedlings were grown for 31 weeks in pats of silica sand with the initial 13-week under dilated complete nutrient solution and the final 11-week under single element deficiency nutrient solutions. Visual symptom development was closely examined, and the growth and nutrient status wore analyzed at the end of the study.
According so the results, the nitrogen deficient seedlings were smaller than the normal, and their old leaves were initially yellowish in color then finally become red. With phosphorus deficiency, loaves of the seedlings turned to dark purplish bloc ruler. Bottom leaves changed to yellowish color, and scorchea at leave tip and margin in K-deficiency seedlings. With calcium deficiency, top young leaves at the seedlings had dark brown spots. Old leaves had interveinal chlorosis and dropped prematurely in the magnesium deficient seedlings.
The growth of Eucalyptus urophylla seedlings were reduced as resulted from the nutrient deficiency. The total dry weight of N-defined seedlings reduced in only 10.5% of these grown in the complete nutrient solution. And, with the deficiency of P, Mg, Ca and K, the total dry weight reduced to 56.3%, 82.7%, 91% and 96.3%, respectively. This indicated that nitrogen would be the crucial nutrient for the growth of Eucalyptus urophylla seedlings and the imprortance of phosphorus came next to nitrogen for the seedlings growth.
The abnormal growth of nutrient deficient seedlings was partially caused by the imbalance of nutrient as indicated by the deviation of the nutrient ratio of those nutricnt deficient seedlings from those in complete nutrient solution.

並列關鍵字

Eucalyptus urophylla ； Macronutricnt deficiency ； Nutrient status