巨量元素缺乏對赤桉苗木生長及養分狀況之影響

Effect of Macronutrient Deficiency on the Growth and Nutrient Status of Eucalyptus camaldulensis Seedlings

程煒兒(Wei-Er Cheng) ； 洪富文(Fu-Wen Horng)

《林業試驗所研究報告季刊》 4卷4期 (1989/12) Pp. 167-175

https://doi.org/10.7075/BTFRI.198912.0167

摘要

為探討赤桉苗木缺乏巨量元素所呈現之症狀，以及養分缺乏對生長和養分狀況之影響，供為研判該樹種營養缺乏之依據，並提供施肥參考，特以養分缺乏之培養液培育苗木，經18週生長所得結果是：1.缺氮植株症狀出現最早，且明顯。植株矮小，無分枝，葉片黃化，下層葉離層前變桃紅色。2.巨量元素缺乏對苗木生長影響最鉅者為氮素缺乏，各項生長量均大幅下降，地上部乾物重僅為完全營養液培育苗木之9%；其次是缺磷，為81%；缺鉀為82%。除缺氮外，缺鉀赤桉苗木根乾重為完全營養液者之67%。3.除缺鎂(-Mg)之地上部乾物重外，赤桉苗木之各項生長量，培育於完全營養液與缺鈣(-Ca)，缺鎂(-Mg)及缺硫(-S)者間差異均不顯著。4.赤桉苗木之葉片養分濃度，可反應苗木及營養液之養分狀況。營養液中缺乏某種養分時，其葉片中該養分之濃度亦低。5.與生長在完全營養液中赤桉苗木葉片中各養分濃度間之適當比例相比較，可顯示出於巨量元素缺乏下所導致各養分濃度間之不平衡。

關鍵字

赤桉 ； 巨量元素 ； 養分缺乏症狀 ； 養分濃度 ； 養分狀況

並列摘要

The Growth, nutrient status and symptoms of nutrient deficiency of 18-week-old Eucalyptus camaldulensis seedlings grown in pots of silica sands and irrigated with various macronutrient-deficient solutions were studied. The aim of this study is to develop a reference guide for the diagnosis of macronutrient deficiency and for proper fertilization of this fast-growing species in plantation forests in Taiwan.
Conspicuous symptoms of nitrogen deficiency developed rapidly and the seedlings were small with no branch. All leaves were yellowish and the lower part turned reddish before falling. The dry weight of the seedlings grown in nitrogen-deficient nutrient solutions dropped to only 9% of the control seedlings supplied with complete nutrients. With potassium and phosphorus deficiency, the dry weights reduced to 82% and and 81%, respectively. No growth differences were found for Ca-, Mg- and S-deficient seedlings when compared with the control except for the above ground biomass of the Mg-deficient seedlings. The results indicated that nitrogen would be the major limiting factor for seedling growth, at least at the early stage.
When a specific macronutrient was removed from the nutrient solution, the resulted seedlings also has lower concentrations of the nutrient in its leaves indicating a nutrient imbalance as compared with the control seedlings.

並列關鍵字

Eucalyptus camaldulensis ； Macronutrient ； Nutrient deficiency