There are various hypotheses on the relative importance of the individual soil-forming factors of Jenny’s (1941) functional-factorial approach. The quantitative influence of each soil-forming factor on the expression and rates of soil-forming processes, and in particular the influence of the different factors in combination, have not yet been fully explored. The aim of this study was thus to quantify the influence of the soil-forming factors on the rates of podzolization, using data from 48 studies of soil chronosequences developed in sandy parent materials, located in the humid mid and high latitudes. These studies contained altogether 259 soil profiles of known age, for which we tested existing hypotheses on the influence of different soil-forming factors. The formation of an E horizon and its increase in thickness over time is one of the characteristic features of Podzol formation. As it is one of the few features that was described in all 48 studies, we used it as an indicator of progressive podzolization. Through statistical analysis, we investigated how E horizon thickness is affected by latitude, longitude, mean annual precipitation, mean annual temperature, range between minimum and maximum monthly temperature, annual number of days with frost, vegetation class, sand content, clay content, and soil age.

Because E horizon thickness exhibited a zero-inflated (semi-)continuous distribution, we opted for a zero-altered gamma (ZAG) model, consisting of a Bernoulli and a Gamma part. The Bernoulli part shows how the probability of the presence of an E horizon changes with soil age and environmental conditions. The Gamma part of the ZAG model allows for capturing the effects of the covariates on E horizon thickness.

Our results indicate that vegetation is the most important factor for both (1) the age at which podzolization starts (used indicator: first occurrence of an E horizon), and (2) the rate of podzolization thereafter (used measure: increase of E horizon thickness with soil age). Climatic factors such as mean annual precipitation and range of temperature play subordinate roles. They can be important in determining the time to initiation of podzolization, but are less important for the rates of podzolization. Within this set of sandy soils, we did not identify a significant influence of sand content, neither on the start nor the rates of podzolization.

关于詹妮（1941）功能因子方法中各个土壤形成因子的相对重要性，存在各种假设。尚未充分探讨每种土壤形成因子对土壤形成过程的表达和速率的定量影响，尤其是不同因素组合的影响。因此，本研究的目的是使用来自48个位于湿润中高纬度地区的含沙母质中的土壤时序序列研究的数据，量化土壤形成因素对土壤过饱和化速率的影响。这些研究共包含259个已知年龄的土壤剖面，为此我们测试了关于不同土壤形成因素影响的现有假设。E层的形成及其随时间的厚度增加是Podzol形成的特征之一。由于它是所有48项研究中描述的少数几个功能之一，因此我们将其用作进行过时过时化的指标。通过统计分析，我们研究了E层厚度如何受纬度，经度，年平均降水量，年平均温度，最低和最高月温度之间的范围，年冻日数，植被类别，砂含量，黏土含量和土壤年龄。

由于E层厚度显示出零膨胀（半）连续分布，因此我们选择了零变化伽玛（ZAG）模型，该模型由伯努利和伽玛部分组成。伯努利部分显示了E地平线存在的概率如何随土壤年龄和环境条件而变化。ZAG模型的Gamma部分允许捕获协变量对E层厚度的影响。

我们的结果表明，植被是以下两个因素中最重要的因素：（1）开始过土化的年龄（使用的指标：首次出现E地平线），以及（2）之后的过土化率（使用的措施：E地平线的增加厚度随土壤年龄而变）。气候因素，例如年均降水量和温度范围，起着次要作用。它们在确定开始过磷酸化的时间中可能很重要，但对于过磷酸化的速率则不那么重要。在这组沙质土壤中，我们没有发现含沙量的显着影响，无论是对开始或过时化的速率都没有影响。