| dc.description.abstract | 本研究目的在探求各種不同的土壤酸度，尤其曾文水庫上游地帶不能栽種其他作物的極鹼性土壤，對於香茅草生育、收油量及油分品質之影響，提高臺灣山地之利用價值及香茅油產量。土壤係取自中和鄉的山坡地，其PH值為4.2，然後以石灰中和調整為PH5.5及6.5；並在臺南縣左鎮採取PH值7.6之土壤，試驗處理分為4種，重複6次，二年收割6次，試驗結果如下：
1. A處理PH4.2極酸性土壤香茅草生育情形，株高、分蘗數、草產量皆較其他處理為低，尤其收油量較其他處理與顯著差異，可見在極酸性土壤不適於香茅草的生長。
2. D處理PH7.73．自臺南縣左鎮所採同之極鹼性土壤在本所缽栽試驗下，發現其生長情形良好，產草量、收油量均高，故在鹼性山坡地上推廣種植香茅草，不但能提高山地之利用價值，且可收水土保持防洪效果。
3.C處理PH6.5，香茅草生育情形，株高、分蘗數、鮮草產量、收油量均較其他處理為高。
4．收割前割取葉片，以切片機切片鏡檢香茅草葉部含油組織油滴分佈情形，其油滴呈小球狀，第一次至第六次收割前鏡檢結果PH6.5處理之油滴最多，PH7.6次之，4.2最少。
In order to clarify the effect of different soil pH on the oil yield and quality of Citronella Grass, the pot culture experiment and chemical analysis was conducted. Special emphasis was put on the growth of Citronella on the strong alkaline soil of the upper steam region of Tseng Wen Dam, where is regarded as barren land and no crops can be cultivated. The experimental soil with pH 4.2 was taken from hilly land of Chung-Ho Town. The soil was adjusted to pH 5.5 and pH 6.5 by liming. The soil with pH 7.6 was also taken from Tsocheng, Tainan Prefecture. Thus, four different soil pH values (pH 4.2, 5.5, 6.5 and 7.6) was laid out in a complete randomized block design with six replications for pot culture experiment. The results of experiment with six harvests during two years are summarized as follows:
1. Citronella grown on the soil of pH 4.2 showed a decrease in plant height, tiller number, grass yield, and especially oil yield as compared with that grown on other soils. It was found that the growth of Citronella grass was unsuitable in this strong acidic soil.
2. The soil taken from barren hilly land pH 7 .6 was found to be better in the growth of grass and higher in grass yield, oil yield and citronellal content. It was suggested that this strong alkaline hilly land can be recommended for cultivation of Citronell grass to improve the utilization arid soil conservation of land.
3. The treatment of pH 6.5 soil, which was limed from acidic soil, showed the highest growth rate of plant height, tiller number, fresh grass yield and oil yield, suggesting the importance of liming to the acidic soil.
4. Leaf blade was cut six times before harvest by microtome to investigate the distribution of oil drops in the tissue. The result of observation by microscope indicated that distribution of tiny oil drops was the largest in the sample of the treatment of pH 6.5, that of treatment of 7 .6 came next, and that of pH 4.2 was the smallest. | en_US |
