MODELS FOR RELATING PH MEASUREMENTS IN WATER AND CALCIUM-CHLORIDE FOR A WIDE-RANGE OF PH, SOIL TYPES AND DEPTHS
MODELS FOR RELATING PH MEASUREMENTS IN WATER AND CALCIUM-CHLORIDE FOR A WIDE-RANGE OF PH, SOIL TYPES AND DEPTHS
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DOI：
10.1007/bf00009563
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发表时间：
1995-04-01
期刊：
影响因子：
4.9
通讯作者：
AITKEN, RL
中科院分区：
文献类型：
--
作者：
AHERN, CR;BAKER, DE;AITKEN, RL
土壤 pH 值通常在水 (pH(W)) 或 0.01 M CaCl2 (pH(Ca)) 中测量。这些方法之间转换的需要导致了针对有限土壤套件的线性、二次和三次多项式关系的发布。考虑到绘制大范围土壤和 pH 值时这种关系的适用性，我们针对昆士兰州土壤调查和现场实验地点的 7894 个样本中的每一个样本建立了 pH(W) 和 pH(Ca) 值数据库。研究了所有土壤的 pH(W) 和 pH(Ca) 之间的关系，并提出了检验土壤深度和土壤类型对这种关系的影响的初步结果。对于所有土壤和深度，线性回归解释了 93.2% 的变化，但不能预测 pH(Ca)，无论 pH(W) 值非常高或低。包含 pH(W) 的二次和三次方可显着解释更多的 pH(Ca) 变化 (R(2) = 0.94)，所得曲线在高 pH 值和低 pH 值下与数据更好地匹配。对地表、次表层和底土分组的分析并未揭示 pH(W) 和 pH(Ca) 之间的关系因深度而存在任何明显差异。相反，土壤类型之间的关系差异很明显。一般来说，轻度淋滤风帆具有线性关系，而风化土壤在低pH值下具有明显的曲线关系。
Soil pH is commonly measured in water (pH(W)) or 0.01 M CaCl2 (pH(Ca)). The need to convert between these methods has led to the publication of linear, quadratic and cubic polynomial relationships for limited suites of soils. Concerns over the applicability of such relationships when mapping a wide range of soils and pH led to the establishment of a database of pH(W) and pH(Ca) values on each of 7894 samples from soil survey and field experimental sites in Queensland. The relationship between pH(W) and pH(Ca) across all soils was investigated and preliminary results examining the effect of soil depth and soil type on the relationship are presented.For all soils and depths, a linear regression accounted for 93.2% of the variation but did not predict pH(Ca), well at very high or low pH(W) values. The inclusion of second and third powers of pH(W) accounted for significantly more of the variation (R(2) = 0.94) in pH(Ca) and the resultant curve matched the data better at high and low pH.Analysis of surface, sub-surface and subsoil groupings did not reveal any appreciable differences in the relationship between pH(W) and pH(Ca) attributable to depth. In contrast, differences in the relationship were evident between soil types. Generally, the mildly leached sails had linear relationships, while the weathered soils were distinctly curvilinear at low pH.