台北地區都市植栽土壤調查分析與杜鵑花管理方式之改進

台北地區具有多種質地的土壤。由調查所調查的四大類型區域共有10種土壤類型，以粘壤土(CL)40.3%最多，最少為粘土(C)1.49%。不適合植物生長因子的比例以有機質含量不足(< 3%)佔比例最高，而Soil pH則佔比例最少低。由體土壤剖面來看，分層多屬粘質土，30公分以下常見建築廢棄物及土層分層堆積的狀況。除硬度限制根系分佈外，土層硬盤的上層也通常是水分及鹽分累積較多的區域。各土壤特性間其互具有相關性(正負皆有)；以單一特性的數據是無法正確判斷土壤的狀況。良好的綠美化土壤管理需先進行基地土壤的特性調查後，進一步調配出適合當地的綠美化客土，使植物生長良好，增添都會景觀生命力。杜鵑花對土壤質地選擇較不嚴，排水通氣良好需良好。栽培地有機質含量的不足(3%以下)是共同的問題。精緻管理對杜鵑花生長較好。夏季管理時應適度遮陰40%。適合杜鵑花生長範圍可以到pH 4-6.5 (但仍以4.5-5.5更佳)。土壤含水量為田間容水量的65-80%。試驗中若有機質含量約18%與pH 5下EC值達750 µS.cm-1植株仍可生長良好，可推測是有機質含量增加土壤緩衝能力的關係。種植杜鵑花土壤有機質的添加至少3%以上（但仍建議達到10-15%）並可施用2000 ppm硫酸鈣，栽培時應使根系與介質充分混合。修剪在杜鵑花的管理十分重要。在不同的品種Rhododendron mucronatum cv. Akemono(SA)、Rhododendron mucronatum(W)、Rhododendron pulchurm(P)修剪試驗可瞭解，抽新芽至可見花芽大概可分為5個階段。5月及以疏剪有最高花芽產生率及花苞數。修剪時間應於5月中前完成。修剪程度可分為疏剪及重度修剪兩種方式。

關鍵字

土壤調查；修剪管理；客土

並列摘要

The Taipei area has a variety of soil textures.There are 10 soil types in the four major types of areas surveyed by the survey, with clay loam (CL) 40.3% being the most, and clay (C) being the least 1.49%.The proportion of unsuitable plant growth factors is the highest proportion of organic matter content (< 3%), while the proportion of Soil pH is the least.From the perspective of the soil profile, the layering is mostly clay soil, and construction waste and soil layers below 30 cm are common in the state of layered accumulation. In addition to the hardness limiting root distribution, the upper layer of the soil hard disk is usually an area where water and salt accumulate more. The soil characteristics are interrelated (both positive and negative); the data of a single characteristic cannot correctly judge the condition of the soil. Good green and landscaping soil management needs to first investigate the characteristics of the base soil, and then further deploy suitable local green and landscaping guest soil to make plants grow well and increase the vitality of the urban landscape. Rhododendron is not strict in choosing soil texture, and good drainage and ventilation are required. Insufficient organic matter content (below 3%) in cultivated land is a common problem. Exquisite management is better for the growth of rhododendrons. During summer management, 40% of the shade should be properly shaded. The suitable azalea growth range can reach pH 4-6.5 (but 4.5-5.5 is still better). The soil moisture content is 65-80% of the field capacity. In the experiment, if the organic matter content is about 18% and the EC value reaches 750 µS.cm-1 at pH 5, the plants can still grow well, it can be inferred that the organic matter content increases the soil buffer capacity. The soil organic matter for planting rhododendrons should be added at least 3% (but 10-15% is still recommended) and 2000 ppm calcium sulfate can be applied. The root system should be fully mixed with the medium during cultivation. Pruning is very important in the management of azaleas. In different varieties of Rhododendron mucronatum cv. Akemono (SA), Rhododendron mucronatum (W), Rhododendron pulchurm (P) pruning experiments, we can understand that the new shoots can be divided into 5 stages. May and thinning have the highest flower bud production rate and flower bud number. The time of pruning should be completed before mid-May.The degree of pruning can be divided into two methods: thinning and heavy pruning.