植生型與施肥作業對濱岸帶土壤水化學性質的影響

Effects of Vegetation Cover Types and Fertilization on Soil Solution Chemistry of Riparian Zones

夏禹九(Yue-Joe Hsia) ； 金恆鑣(Hen-Biau King) ； 洪富文(Fu-Wen Horng) ； 黃正良(Jeng-Lian Hwong) ； 王立志(Lih-Jih Wang) ； 劉瓊霦(Chung-Bin Liou)

《林業試驗所研究報告季刊》 9卷1期 (1994/03) Pp. 39-50

https://doi.org/10.7075/BTFRI.199403.0039

摘要

本報告是研究植生型（天然灌木叢、柳杉人工林，琉球松樟樹人工林及茶叢）及土地經營方式（天然林地、人工林地、茶園與施肥作業）對溪流濱岸帶的土壤養分緩衝效用系列研究之一部分。試驗結果發現，施放400kgha^(-1)，的NPK(20-5-10)完全肥料二年半後：土壤水的K、P養分濃度（中值），在柳杉人工林試區，不因施肥作業而顯明的較高；灌木試區的土壤水NH4(上標 +）濃度皆很低，除NO3(上標 -)濃度在地表水顯著較高（中值為4ppm）外，其餘所有養分濃度不因施肥而有差異。茶園長久施肥的結果，降低表土50公分以內的pH值（即酸化），而且土壤水的養分濃度普遍比毗鄰的琉球松樟樹人工林試區低，然而NO3(上標 -)濃度在表土25cm內以茶園較高，25cm以下的茶園土壤則比相鄰對照區森林土壤較低。此試驗結果顯示濱岸帶對土壤中養分（甚至包括農藥）的緩衝作用視土壤因素（母質堆積、發育度、土壤性質），土地利用（如茶園經營），地被植物的生長勢及根系的吸收養分能力而定，因此認為各濱岸帶的寬度宜就各案討論決定。

關鍵字

森林施肥 ； 茶園施肥 ； 水質 ； 濱岸帶

並列摘要

Riparian zones varying with vegetation cover types (Cryptomeria japonica stand, hardwood bushes, and Pinus luchuensis and Cinnamomum camphora, and Camellia sinensis plantation) and land use management (forest fertilization and conventional tea plantation practices) were tested for their buffering effects. The results of 3-year (from Feburary, 1989 to April, 1991) monitoring nutrient concentrations in surface and subsurface (25-, 50- and 95-cm depths) runoffs indicated that application of 400 kgha^(-1) NPK (20-5-10) fertilizers did not change median concentrations of K and P in fertilized and controlled plots for conifer mixed with hardwood plantation. The maximum concentrations, however, of the K and P were substantially higher in fertilized plots than in controlled plots. Median concentrations of phosphate and potassium, except nitrate which was more concentrated in surface runoff than in subsurface runoff, were close for both fertilized and controlled plots of hardwood bushes. Long-term conventional tea plantation practice decreased soil pH for the soil solution of upper 50 cm depth, and concentrations of all nutrients (except for nitrate) at all depth were lower as compared to the soil solution of adjacent forest. The median nitrate concentration in 25 cm depth was higher (2.5ppm) in soils under tea plantation and lower (1.9ppm) in adjacent forest soils. However, the reverse was true for nitrate concentration below 25 cm depth. The results revealed that the buffering effect of riparian zone varied with soil factors (mode of parent material deposition, degree of soil formation and properties), land use (such as tea plantation), growth vigor of vegetation cover and effectiveness of active rootings. It was concluded that the effective buffering width of any segment of riparian zone should be evaluated individually.

並列關鍵字

forest fertilization ； tea plantation ； water quality ； riparian zone