|dc.description.abstract||為減少傳統灌溉造成20%-60%的溢流 和淋溶對環境造成污染，本研究探討不同養 液濃度於潮汐灌溉系統下對綠巨人白鶴芋 生長之影響，並比較潮汐灌溉與傳統澆灌對 其生產之效益。潮汐灌溉宜在1/2 至1/4 Johnson 氏營養液下得到品質較佳的綠巨人 白鶴芋。介質EC 值隨營養液濃度增加而增 加，到栽培後期全量營養液處理者介質的上 層EC 高達7.19mS/cm，然而在使用1/4 Johnson 氏營養液用量下，其中上層介質之 EC 值仍能維持在0.79mS/cm 在右，不會影 響根部之生長，顯示低肥量適合綠巨人白鶴 芋潮汐灌溉之生產方式。潮汐灌溉生產的綠 巨人白鶴芋在維持相同灌溉類頻率的情況 下，植株之生長量與傳統澆灌生長之植株並 無顯著差異，能夠減少下位黃葉和皺摺葉之 發生。減少用水量達33%及提高水份利用效 率達40%，能減少氮素之使用量達33%， 椰粉之充氣孔隙度和保水力較加拿大水苔 泥炭為低，然而椰纖以33-60%與珍珠石、 蛇木屑混合後，其物理性質皆符合理想之範 圍內。椰粉和泥炭苔的pH 值皆在理想範圍 (~pH5.8) ， 然而椰纖的EC 較高 (2.16mS/cm)，以飽和萃取法(SME)分析其元 素含量，Na 含量為泥炭苔之6 倍，K 含量 為泥炭苔之3 倍，然而椰纖含P、Mg、Ca 等元素較少。若介質以椰粉取代，氮素用量 在4-8mM 處理下，潮汐灌溉處理在地上部 乾重及葉面積皆相等於泥炭苔以4-8mM 氮 素澆灌處理者。葉片中氮含量隨施用氮素增 加而增加，但施用量增加至16mM 時。葉 片K、Ca 和Mg 元素含量隨著葉片中N 元 素含量增加而遞減，壞疽葉片數亦同時有增 加之趨勢。在低氮素使用下，潮汐灌溉可以 部分解決椰粉保肥力不足之問題，在使用椰 粉取代泥炭苔之同時，配合潮汐灌溉系統可 獲得更佳之效益。||zh_TW|
|dc.description.abstract||In order to reduce the irrigation run-off and contamination of the underground water, effects of different nutrient levels were investigated in Spathiphyllum “Sensation” grown in an ebb and flow system, and comparison on the growth with hand-watering was also determined. Environmental and economical concerns had generated interest in the development of substitutes to peat, under the conditions of this study, coir-based media was also used in the experiments to compare the growth responses of Spathiphyllum “Sensation” under the ebb and flow system. Plants grew equally well from a range of 1/4 to full-strength of Johnson’s solution in the ebb and flow system, indicating the possible luxury consumption of plants was grown in the full-strength treatment, moreover, full-strength treatment produced more necrotic leaves and reduced the root growth. However, the chlorophyll content was lower in the 1/4-strength treatment and leaves showed chlorotic spots symptoms. In the full strength treatment, a high EC of 7.19mS/cm was measured in the upper portion of the medium measured at the end of the experiment, whereas for the 1/4 strength treatment, EC at the root zone was maintained at 0.79mS/cm, which was considered to be save for the plant growth. These results indicated that a range of 1/4 to half strength of Johnson’s solution was optimum for the growth of Spathiphyllum“Sensation” in the ebb and flow system. From September, 1997 to April, 1998, there were no difference in the plant growth between irrigation methods at the same irrigation frequency, however plants grown in the ebb and flow system had the fewest number of chlorotic and puckered leaf. From May, 1998 to January, 1999, plants growth in the ebb and flow system was better than that of the hand watering treatment. In additions, the ebb and flow system could save water and nitrogen use by 33% and increased the water use efficiency by 40%. Coirdust had a lower air-filled porosity and water holding capacity than Canadian sphagnum peat. Growing mix containing 33- 60% of coirdust with perlite and treefern exhibited desirable physical properties, the pH of coirdust was desirable but EC was higher than that of peat. Na and K were tested to be 6 and 3 times higher than peat respectively, however, the P, Mg, Ca content of coirdust was less than optimum range. No difference was observed in plant growth among various medium mixture containing either 33-50% of coirdust or 33% of peat. However, the coirdust content higher than 50% could reduce plant growth. In another experiment with medium composed of 50% of perlite and various proportions of coirdust and peat, results indicated that coirdust content up to 25% gave lower root dry weight. All these suggested that the chemical properties would affect the root growth of Spathiphyllum“Sensation”. Maximum growth was observed in 8mMN applied in the ebb and flow system by using peat-mix as the media, while plants grown in coirdust were equally well with the ebb and flow by 4-8mM-N treatment. As a medium in the ebb and flow system, it appeared that coirdust could be a good substitute for peat. For either peat or coirdust-based medium, the optimum nitrogen requirement for Spathiphyllum “Sensation” in the ebb and flow system was 8mM. Plant dry weight decreased and necrotic symptoms occurred when nitrogen concentration exceeded 16mM in all treatments, and root dry weight decreased sharply especially in the ebb and flow treatment. Increasing nitrogen concentration paralleled increased the no of necrotic leaves, and root growth foliar N content, while K, Ca and Mg content was decreased. Due to the absence of leaching in the ebb and flow system, it was suggested to reduce the nitrogen application rates in order to maintain good quality of Spathiphyllum “Sensation”. Fertigation using once in every 3 days was shown to be optimum for peat and coirdust-mix in the ebb and flow system, while increasing the frequency to once a day was unnecessary. Coconut husk-mix had a poor water retention capacity, but the problem could be solved by increasing the fertigation frequency to once a day, suggesting that coconut husk is suitable for constantly irrigation.||en|
|crisitem.author.dept||Horticulture and Landscape Architecture||-|
|crisitem.author.parentorg||College of Bioresources and Agriculture||-|
|Appears in Collections:||園藝暨景觀學系|
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