不同量牛糞堆肥對青脆枝生長及生理營養的影響

Abstract

青脆枝 (Nothapodytes foetida (Wight) Sleumer) 為喜樹鹼含量高之植物，而臺灣的蘭嶼島是最主要的原產地。喜樹鹼為植物鹼，其形成之量可能與氮之營養有關。因此，本論文之目的為探討以有機肥料為氮源，在兩種施肥量下，青脆枝之生長、養分吸收及其喜樹鹼濃度之差異。所使用之有機肥料為牛糞堆肥，分為高量 (Org2) 與低量 (Org1) 處理，並以化學肥料之處理 (Chem) 為對照，共三種處理，栽培青脆枝，以1/2000 a的Wagner盆，裝十公斤土壤，所有肥料均於種植前以基肥全層施入。試驗以逢機完全區集排列進行，每處理四重複，經栽培六個月後，收穫全株，植物體經洗淨後，分成根、莖與葉三部分，在65℃下烘乾；同時採取土壤樣品，風乾磨碎、過篩後，進行做化學分析。結果顯示，Org2處理因施用之養分元素量較高，可顯著提高土壤EC值、有機質、硝酸態氮、Bray-1 P、Mehlich III可萃取性鉀、錳濃度。Chem處理與Org1處理提供土壤之氮量、硝酸態氮、Bray-1 P、Mehlich III可萃取性鉀、鈣、錳、銅、鋅的效果相似。三種處理對青脆枝植株乾重、不溶性氮、磷、鉀、鈣、鎂、可溶性醣、多醣、喜樹鹼含量無顯著差異之影響。Org2處理因施用之肥料量較高，導致氮之吸收量高，進而增加植體中之硝酸態氮、銨態氮、可溶性還原態氮之濃度。三種處理對青脆枝喜樹鹼濃度無顯著差異之影響，但青脆枝植株根部喜樹鹼濃度有Chem ＞ Org1 ＞ Org2之趨勢。

Nothapodytes foetida (Wight) Sleumer (N. foetida) is a high concentration camptothecin-containing plant. It’s a native plant of Taitung country interfiled-Lanyu Island, Taiwan. Camptothecin is an alkaloid, and its concentration in the plant might be related to the nitrogen (N) nutrition. The objective of this study was to investigate the effect of two rates of N fertilizer on the growth, nutrition uptake, and camptothecin concentration of N. foetida. The treatments composed of two rates of cattle dung compost (Org1 and Org2) and one rate of chemical N fertilizer (Chem). All treatments replicated four times and arranged in randomized complete block design. The plants were cultivated in 1/2000 a Wagner pots in which contained 10 kg air-dried soil. All fertilizers were applied as basal dressing and mixed completely with soil before planting. After six months of growth, the whole plant was harvested. Being cleaned with water, the plants were separated according to the leaves, stems, and roots and dried at 65℃ oven. The soils were also sampled after harvesting of the plants. The nutrient concentrations of plants and selected soil chemical properties of soils were analyzed. The results showed that the soil of Org2 treatment had higher EC, organic matter concentration, nitrate N, Bray-1 phosphorous (P), and Mehlich III extracted potassium (K) and manganese (Mn) than those of the other treatments after harvesting of plant. There were no significant differences in total N, nitrate N, Bray-1 P and Mehlich III extracted K, calcium (Ca), Mn, copper (Cu), and zinc (Zn) between Org1 and Chem treatments. There were no significant differences in plant dry weight and the concentrations of insoluble N, P, K, Ca, magnesium (Mg), soluble sugar, nonstructural polysaccharide, and camptothecin among three treatments. However, the concentrations of nitrate N, ammonium N, and soluble reduced N of Org2 treatment were higher than those of the other treatments. These results can be attributed to the higher amount of N in Org2 treatment. The camptothecin concentration in roots was in the order: Chem ＞ Org1 ＞ Org2, however no statistically significant difference existed.