Walkley-Black法分析土壤有機碳之回收率－以台灣非石灰質森林土壤為例

Recovery Rate of Organic Carbon by the Walkley-Black Procedure - Non-calcareous Taiwan Forest Soils as Examples

杜清澤(Chin-Tzer Duh) ； 黃菊美(Chu-Mei Huang)

《台灣林業科學》 32卷3期 (2017/09) Pp. 259-265

https://doi.org/10.7075/TJFS.201709_32(3).0007

摘要

本研究分別以Walkley-Black法和元素分析儀分析562個台灣非石灰性森林土壤樣本的有機碳含量，以元素分析儀量測值為標準，探討Walkley-Black法氧化不同林型(針葉林、針闊葉混合林、暖溫帶闊葉林、針葉人工林、竹林－竹闊葉混合林、闊葉人工林、亞熱帶闊葉林)、化育層(A、B和C層)土壤有機碳的回收率(recovery rate)，與求其適用的校正值。結果Walkley-Black法測得、未經校正的有機碳濃度分布為0.06～36.4%，元素分析儀測值則為0.08～44.6%，回收率介於50.4至93.7%之間，平均為75.6%。森林土壤有機碳濃度之高低與Walkley-Black法之回收率無顯著相關。各林型皆以A層有較高的回收率，B和C層之間無顯著差異。雖然部分林型回收率有顯著差異，但諸林型之校正值頗為接近，其中A層校正值分布在1.19～1.27，B和C層在1.29～1.37，平均校正值分別為1.24和1.34。建議在較大範圍土壤有機碳估算時，仍可以用通用值1.30，但若欲更為精確估算台灣森林土壤有機碳含量時，A層可用1.24，B和C層可用1.34。

關鍵字

Walkley-Black法 ； 回收率 ； 森林土壤 ； 校正值

並列摘要

Soil organic carbon (SOC) contents of 562 Taiwan non-calcareous forest soil samples were determined by the Walkley-Black (WB) method and an elemental analyzer. The data analyzed by the elemental analyzer were taken as the standard, to obtain the SOC recovery rate by the WB method in 7 forest types (coniferous forest, coniferous-broadleaf mixed forest, warm temperate broadleaf forest, coniferous plantation, bamboo/bamboo-broadleaf mixed forest, broadleaf plantation, and subtropical broadleaf forest) and their soil horizons (A, B, and C), in order to obtain suitable correction factors. SOC data of the WB method and the elemental analyzer were 0.06~36.4% and 0.08~44.6%, respectively. Recovery rates ranged 50.4~93.7% with an average of 75.6% for all samples. There was no significant correlation between SOC concentrations and WB recovery rates. All forest types had higher recovery rates in the A horizon than the B and C horizons, while no significant difference was found between the B and C horizons. Although recovery rates significantly differed among forest types, the correction factors were quite similar. Correction factors of the A horizon ranged 1.19~1.27, and those of the B and C horizons were 1.29~1.37, while averages were 1.24 and 1.34, respectively. It is suggested that a general value of 1.30 can be used to estimate the organic carbon content of a wide range of soils; however, for a more-accurate estimate of SOC contents in Taiwanese forests, the A horizon can use 1.24, and the B and C horizons can use 1.34.

並列關鍵字

Walkley-Black method ； recovery rate ； forest soil ； correction factor