The objective of this study was to evaluate the contribution of the constituents sand, silt and clay to the tensile strength and, by extension, to the genesis of horizons with cohesive character, as well as to know the variability of these attributes in the soil horizon. Horizons with and without cohesive character were selected in six soils, in which samples were collected at the top, middle and base in blocks with dimensions of 0.15 × 0.20 × 0.10 m for width, length and height, respectively. Aggregates/clods were obtained from the collected material and used in the tensile strength tests. Additionally, the contents of sand (with fractionation in five classes: very coarse, coarse, medium, fine and very fine), silt and clay were quantified. Data analysis was carried out considering a completely randomized design, in a 6 × 2 × 3 factorial scheme (six soils, two degrees of cohesion, three positions in the horizon) with five replicates. F test was applied for the analysis of variance and Tukey test was used to compare the means (p ≤ 0.05). Sand fractionation data were analyzed using the microcomputer program PHI, which calculates different statistical parameters (relative frequency, cumulative frequency, mean and standard deviation). The degree of sorting of the sands was defined based on the standard deviation (σ) of the phi values, namely: very well sorted, well sorted, moderately sorted, poorly sorted, very poorly sorted and extremely poorly sorted. Regression analyses were also performed between the mean values of tensile strength and the particle-size fractions and standard deviation of the phi values relative to sand. Tensile strength was higher in horizons with cohesive character, reaching mean value of 49.9 kPa, followed by the values of soils without this attribute (mean value of 34.1 kPa). The horizons with and without cohesive character showed significant variations in total sand contents, but without differing in relation to the textural class – sandy clay loam for five of the soils evaluated. It was concluded that particle size alone does not explain the manifestation of the cohesive character in soils, but the constituents sand, silt and clay have a significant effect on its genesis; because it causes more closed packaging, poor sorting of sand grains is one of the primary factors in the genetic process of cohesive character in soils. There is a significant variation in the amount of sand and silt in at least one of the top, middle and bottom positions when the cohesive and non-cohesive B horizons are analyzed. In general, in horizons with a cohesive character the tensile strength of aggregates/clods decreases from top to bottom.

这项研究的目的是评估沙，粉砂和粘土成分对抗拉强度的贡献，并进而评估具有粘结性的地层的成因，以及了解这些属性在土壤层中的变异性。 。在六种土壤中选择具有和没有凝聚力的地层，在顶部，中部和底部分别以宽度，长度和高度为0.15×0.20×0.10 m的尺寸收集样本。从收集的材料中获得骨料/凝块，并将其用于抗拉强度测试。此外，还对沙子（分为五类：非常粗糙，粗糙，中等，精细和非常精细），淤泥和粘土的含量进行了定量。考虑完全随机设计进行数据分析，在6×2×3阶乘方案中（六个土壤，两个内聚度，在地平线上三个位置），重复五个。F检验用于方差分析，Tukey检验用于比较均值（p ≤0.05）。使用微机程序PHI分析砂分馏数据，该程序计算不同的统计参数（相对频率，累积频率，均值和标准差）。沙子的分类程度是基于phi值的标准偏差（σ）定义的，即：很好分类，很好分类，中等分类，不好分类，非常不好分类和非常不好分类。还对抗拉强度的平均值与粒径分数和phi值相对于沙子的标准偏差之间进行了回归分析。具有内聚特性的地层的抗拉强度较高，平均值为49.9 kPa，其次是没有此属性的土壤值（平均值为34.1 kPa）。具有和不具有粘结性的地层显示出总沙含量的显着变化，但与质地类别（沙土壤土）之间的关系没有差异（对于五种评估土壤）。得出的结论是，仅颗粒大小并不能解释土壤中黏聚性的表现，但是沙，粉砂和粘土的成分对其形成有重要影响。由于它导致更密闭的包装，对沙粒的不良分类是土壤内聚性遗传过程中的主要因素之一。分析内聚和非内聚B层时，顶部，中部和底部至少其中一个位置的沙粒和淤泥量存在显着变化。一般来说，