The expression cohesive character in soil horizons, regard to their consistency, which ranges from very hard to extremely hard when dry, changing to friable or firm when wet, has been attributed to several processes, many of which have not yet been fully clarified, hence the need for further studies in search of its elucidation. This study aimed to evaluate the contribution of silicon, aluminum and iron associated with poorly crystalline compounds to the cementation of cohesive horizons, as well as to know the variability of tensile strength within the soil horizon. In six soils, Alfisols, Ultisol and Oxisols, the horizons with and without cohesive character were sampled at the top, middle and base positions, collecting blocks with dimensions of 15 × 20 × 10 cm in width, length and height, respectively. The collected material was used to obtain the aggregates/clods, which were subjected to tensile strength tests, and, in addition, the contents of silicon, iron and aluminum constituting oxides of low crystallinity. 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). Regression analyses were also performed between the mean values of tensile strength and silicon, aluminum and iron extracted by ammonium oxalate. Tensile strength was higher in the horizons with cohesive character, reaching mean values of 49.9 kPa, followed by the values found in soils without this attribute (average 34.1 kPa). Silicon and aluminum contents were higher in the horizons with cohesive character, but iron did not follow this trend. The average values for the silicon content in horizons with cohesive character was 0,86 dg kg⁻¹, in contrast with 0,54 dg kg⁻¹ in non-cohesive horizons. The average value for the aluminum content was 4.18 dg kg⁻¹ in horizons with cohesive character and 1.32 dg kg⁻¹ in non-cohesive horizons. In general, it can be stated that all soils evaluated in this study had reduced iron contents, always below or close to 2 dg kg⁻¹, except for the horizon without cohesive character in the Ultisol, evidencing the little expression of this chemical element in the genesis of the cohesive character in soils of Coastal Tablelands. It was concluded that the contents of silicon and aluminum associated with poorly crystalline compounds significantly contribute to the manifestation of cohesion as a diagnostic attribute; iron does not. There is significant variability of tensile strength, especially in the horizons described with cohesive character, with reduction of cohesion from the top to the base.

表达粘着特征的土层，考虑到它们的一致性，其范围从非常硬到极硬干燥时，更改为易碎或公司潮湿时，归因于几个过程，其中许多过程尚未完全阐明，因此需要进一步研究以阐明其原因。这项研究旨在评估与结晶性较差的化合物相关的硅，铝和铁对粘结层的胶结作用的影响，以及了解土壤层内抗拉强度的变化性。在六种土壤（Alfisol，Ultisol和Oxisols）中，在顶部，中部和基础位置取样了具有和不具有粘性特征的地层，收集的块的宽度，长度和高度分别为15×20×10 cm。收集的材料用于获得聚集体/凝块，对其进行抗拉强度测试，此外，还对硅含量，铁和铝组成的结晶度低的氧化物。考虑完全随机设计，以6×2×3阶乘方案（六个土壤，两个内聚度，在地平线上三个位置）进行数据分析，重复五次。F检验用于方差分析，Tukey检验用于比较均值（p  ≤0.05）。还进行了抗拉强度平均值与草酸铵提取的硅，铝和铁之间的回归分析。具有内聚特性的层的拉伸强度更高，达到平均值49.9 kPa，其次是在没有此属性的土壤中发现的值（平均34.1 kPa）。具有粘结性的层中硅和铝含量较高，但铁没有遵循这种趋势。具有内聚性的层中硅含量的平均值为0.86 dg kg ^-1，而非内聚性层中的硅含量平均值为0.54 dg kg ^-1。具有内聚特性的视野中铝含量的平均值为4.18 dg kg ^-1和1.32 dg kg ^-1在非凝聚力视野中。总的来说，可以说，在这项研究中评估的所有土壤中铁含量都降低了，总是低于或接近2 dg kg ^-1，除了在Ultisol中没有粘结性的地层之外，这表明该化学元素在土壤中很少表达。沿海平原土壤粘性特征的起源。得出的结论是，硅和铝的含量与结晶性较差的化合物显着有关，可将内聚力作为一种诊断属性。铁不。抗拉强度存在很大差异，尤其是在具有内聚性的视野中，从顶部到底部的内聚性降低。