Soil Aggregate Instability Index and Statistical Determination of Oscillation Time in Water

A new method for classifying soils on the basis of aggregate stability is presented. The method, based on the concept of an instability index β is simple, quick, and gives reliable results comparable to those obtained with the laborious more commonly used methods. The optimum time of oscillation for the determination of the instability index, β was determined by statistically analyzing data for nine soils. According to this analysis, β is a reliable index of the relative aggregate water‐stability when oscillation times of at least 4 min are used.