Some observations on the stability of soil aggregates to raindrop impact

Summary

The paper sets out to investigate how the characteristics of drop impacts control when soil aggregate breakdown takes place, and what might be the most important mechanisms involved in this breakdown process. A single drop rainfall simulator is used which enables the formation of drops of very different characteristics to impact onto a single soil aggregate. By the use of Principle Components analysis these variations in drop impact characteristics are synthesised into three orthogonal components. Component scores are then regresses against time to aggregate breakdown, the analysis achieves 92% explanation of variation in this dependent variable. The interpretation of the results shows slaking to be of prime importance in aggregate breakdown, it does not preclude physio-chemical mechanisms from this process and therefore provides a base from which these mechanisms can be studied in a new series of controlled experiments.