Full soil particle size fingerprints determined by laser diffraction of 48 selected test samples from Flanders (Belgium)

A set of 48 soil test samples was selected for a study (1) comparing two common methods for granulometric analysis: pipette-sieving method versus laser diffractometry (LD), (2) comparing the results among various LD instruments and (3) analysing the effect size of various settings on LD instruments (e.g. effect of diffraction models & optical parameters). All 48 samples originated from soils of Flanders (North of Belgium) and were taken in 4 landuses (croplands (n=8), grasslands (n=18), gardens (n=13) and natural habitats (n=9)) on the most common soil types and textures. The samples widely varied in organic carbon content and pH. The datasets are the output of the full soil textural ‘fingerprint’ (particle size range from 0,4 - 2000 µm) of the test samples analysed by a Beckman COULTER LS13320 laser diffraction instrument. Pretreatment of the soil samples was conducted according to ISO 11464 and the removal of organic matter and carbonates was done according to ISO 11272 as for the Sieving and Sedimentation method. Background information is given in the presentation (PDF): “Should laser diffraction become the new standard for soil particle size analysis ?” The equivalent LD diameters applied to convert the pipette based standard limits for clay fraction (2 µm) were set to 6 µm when using LD particle sizes and for silt (50 µm) to 63 µm (LD size). For each test sample the full textural fingerprint is given according to size bins showing for each bin the mean fraction (in vol%) of 5 replicated measurements along with the standard deviation (sd) under repeatability conditions. Based on the full fingerprint various fractions can be derived and statistically compared. The full fingerprint is also useful for calibrating pedotransfer functions for estimating other soil physical properties and for in silico modeling purposes.本研究选取48份土壤测试样本，开展三项对比分析：(1) 对比两种常用的土壤颗粒组成分析方法——吸管筛分法与激光衍射法（Laser Diffractometry，LD）；(2) 对比不同激光衍射仪器的分析结果；(3) 分析各类设置参数对激光衍射仪器的效应量（例如衍射模型与光学参数的影响）。 全部48份样本均取自比利时北部佛兰德斯地区的土壤，按照4种土地利用类型采集：耕地（n=8）、草地（n=18）、园地（n=13）与自然生境（n=9），涵盖当地最常见的土壤类型与质地。样本的有机碳含量与pH值变异范围较广。 本数据集为使用贝克曼库尔特（Beckman COULTER）LS13320激光衍射仪器分析测试样本得到的完整土壤质地"指纹"数据，其粒径测量范围为0.4 μm至2000 μm。土壤样本的前处理严格遵循ISO 11464标准，而有机质与碳酸盐的去除流程则参照ISO 11272标准，该流程与吸管筛分法的前处理规范一致。相关背景信息可参阅演示文稿（PDF格式）："Should laser diffraction become the new standard for soil particle size analysis ?" 为适配基于吸管法的黏土粒级（≤2 μm）与粉粒粒级（≤50 μm）的标准限值，激光衍射法对应的等效粒径分别设置为6 μm（黏土粒级）与63 μm（粉粒粒级）。 每份测试样本的完整质地指纹数据均按粒径区间给出，每个区间内包含5次重复测量的平均体积占比（vol%），以及重复性条件下的标准差（sd）。基于完整的粒径指纹数据，可推导得到多种粒级组分并开展统计学对比。该完整指纹数据还可用于校准土壤传递函数（pedotransfer functions）以估算其他土壤物理性质，亦可用于in silico建模相关研究。