三種不同配方之肥料對臺灣白花蝴蝶蘭營養生長與養分吸收之影響

Effects of Three Fertilizer Formulae on Growth and Nutrient Uptake of Phalaenopsis amabilis var. formosana

施用適量肥料可使植物生長良好，且可避免因肥料過量施用而污染環境及浪費資源，進而增加栽培者之收益。本研究探討臺灣白花蝴蝶蘭栽培業者慣用之肥培管理對其生長與養分吸收之影響，以做為栽培及改進配方之參考。選用氮、磷及鉀比例不同之三種商業肥料（30N-10P2O5-10K2O、20N-20P2O5-20K2O及15N-20P2O5-25K2O，代號分別為30-10-10、20-20-20及15-20-25），自2005年1月18日起，以0.5 g•L^(-1)每二週施用一次。栽培期間共五個月，每個月測量各處理之葉面積、葉數、葉與根之乾重，同時測定葉與根之氮、磷、鉀、鈣、鎂、鐵、錳、銅與鋅之濃度。結果三種施肥處理之蝴蝶蘭中苗營養生長前期（一至三個月）之生長良好而處理間無顯著差異，但生長後期（四至五個月），15-20-25施肥處理之葉數、葉面積及葉乾重明顯低於其他處理。顯示15-20-25施肥處理無法提供蝴蝶蘭中苗後期生長足夠之肥效，而其效應則來自氮之濃度太低。兩種濃度磷肥處理比較，對磷之吸收無顯著差異，顯示用低濃度之磷已足。三種鉀濃度中，高鉀之配方15-20-25，雖可提供足量之鉀，但因氮濃度偏低無法增加植株生長。雖然灌溉水（自來水）與水苔介質能供應蝴蝶蘭中苗所需之部分鈣及鎂，但三種處理之蝴蝶蘭苗植體中鈣及鎂濃度皆偏低，顯示肥料配方中應加鈣及鎂。三種施肥處理之蝴蝶蘭植體中之鐵、錳、銅及鋅無顯著差異，也無缺乏徵狀。 Adequate fertilization is necessary for the optimum growth of plants, but excessive fertilizer application is harmful to the environment. The purpose of this study was to determine the effects of three different formulae of commercialized fertilizers on the growth and nutrient uptake of Phalaenopsis amabilis var. formosana during its five-month growth period in 7.5-cm diameter pots. Three fertilizers, 30N-10P2O5-10K2O (30-10-10), 20N-20P2O5-20K2O (20-20-20), and 15N-20P2O5-25K2O (15-20-15) were used. The leaf area, leaf number, dry weights of leaves and roots, and the concentrations of N, P, K, Ca, Mg, Cu, Zn, Fe, and Mn of the leaves and roots of Phalaenopsis plants were measured every month in the experiment. Different fertilizer formulae made no significant difference in plant growth during the first three months, but 15-20-25 formula resulted in the lowest leaf number, leaf area and leaf dry weight during the 4th to 5th month, presumably owing to insufficient N fertilizer. The uptake of P in Phalaenopsis did not differ significantly among treatments, suggesting adequate P supply even in the low P formula. The 15-20-25 fertilizer with high K concentration increased uptake K, but did not enhance Phalaenopsis growth. Increasing N in this high-K formula might improve the growth. Although the tap water and sphaghnum moss medium used in the experiment could supply some Ca and Mg, the concentrations of Ca and Mg of the plants were lower than normal. It seems necessary to add Ca and Mg when using the fertilizer formula. There were no significant differences in Fe, Mn, Cu, and Zn concentrations in each plant part among different treatments. The supply of these trace nutrients from fertilizer, irrigation water, and growth medium seemed adeguate for the growth of Phalaenopsis.