Flocculation

Repeated use of this type of [water] on plants results in deflocculation[] of the soil. Good quality soil consists of loose aggregates which provide natural aeration and ease of root run. Sodium accumulation in soil destroys this natural flocculation and causes the soil to pack.

It might seem that Mr. Holl, whose initial sketches are glorious watercolors, was an unlikely candidate for a job that is all about hydrodynamics. But he credits much of his inspiration to repeated meetings with engineers -- as many as 30 at a time -- to discuss topics like "flocculation" (the process by which particles form coagulated masses, or flocs).