香蕉之營養與肥培管理

Nutrition and Fertilizing Management in Banana

香蕉為需肥量較大之作物，因此，香蕉栽培，若欲高產，除土壤條件（物理性及化學性）必須良好外，則有賴良好之肥培管理始可望達成。惟良好之肥培管理，並非僅單純之大量施用肥料，而係根據土壤之條件，肥料之性質以及香蕉之生育，適時適量施肥，若能再根據土壤或葉片診斷以及耕種經驗，則香蕉之肥培管理，當更臻合理。一般而言，香蕉生長初期（0～5個月時）對肥料反應最敏銳，亦對香蕉產量之決定，最為重要。是故，初期之少量施肥，遠比後期之大量施肥來得重要。氮、鉀為香蕉良好之生長及高產，可能發生不足之元素，香蕉需求之比例的1：3。本省香蕉三要素每年每株施用適量為氮（N）100～200gm，磷（P2O5）50～100gm，鉀（K2O）400～600gm。若以香蕉專用之臺肥4號複合肥料（N-P2O5-K2O=11：5.5：22）而言，每株每年施用量，一般在1.5～2.0kg即已足夠，超量徒增浪費。植體分析技術（或配合土壤分析）為協助了解植物（或土壤）營養狀況以及調整合理施肥上，相當重要之一環，在世界各產蕉地區，已普遍受到重視與運用。然此方面之技術與結果，世界各地仍相當之混亂，因此，有必要針對各地確立正確之採樣方法及養分臨界濃度。在本省，香蕉三要素在抽穗期之臨界濃度，以第3葉片之養分含量，N3.3%；P0.21%；K3.6%為標準。

Banana is a crop of high nutrient requirements. It needs both good soil condition (physical and chemical) and good fertilization management to achieve high yield. A good fertilization management does not mean to apply large amount of fertilizers. Instead, the right timing and rates of fertilizer application based on soil conditions, fertilizer properties and the growth of banana plant are much more important, Furthermore, the management will be more efficient if soil and leaf analysis, and cultural experiences are also integrated into consideration. In general, the early stage of vegetative growth determines the fruiting and yield in banana and fertilizer application during this stage is critically important. Small amount of fertilizer applied at the early stages could be more beneficial than the large quantity applied later. Nitrogen (N) and potassium (K) are nutrients likely to be deficient for the proper growth and high yield production of bananas. The ratio of requirements of N and K are about 1:3. The optimum rates of fertilizers recommended in Taiwan are 100-200gm N, 50-100gm P2O5, and 400-600gm K2O per plant per year, or 1.5~2.0 kg per plant per year of complete fertilizer (N-P2O5-K2O=11-5.5-22). Plant analysis, or combining soil with analysis, helps understanding the plant (or soil) nutrition states, and provides guidances for the adjustments of a programme management. This technique has been highly regarded and applied in the major banana production areas worldwide. However, the technique and knowledge in bananas are still confused. Thus, to established a standard sampling method and the critical concentrations of nutrients for local situation are necessary. In Taiwan, the critical concentrations of N. P and K of the third leaf at shooting stage are 3.3%, 0.21%, and 3.6%, respectively.