Comparison of Three Methods for Soil Homogenization

We used the most common homogenization techniques, namely, grinding and sieving, riffle splitting (open and closed bin), and cone and quartering to homogenize four soils of differing textures. Our objective was to determine the effectiveness, efficiency, and extent of fine particle loss for each technique by examining particle‐size distribution, loss‐on‐ignition organic matter, and pH. Five passes should be used to effectively homogenize a sample, since the least replicate variability almost always occurred after the fifth pass. Riffle splitting was more efficient and had less loss of fines than cone and quartering and is, therefore, the recommended method for soil homogenization. The closed‐bin riffle splitter was apparently better able to contain the loss of fines than the open‐bin riffle splitter. Grinding and sieving (random sampling) was the most efficient process, yet it almost consistently showed greater replicate variability than the other homogenization techniques after the fifth pass, thereby reducing its value for soil homogenization.