Exam 4: Soil Architecture and Physical Properties

Polysaccharides produced by soil microbes and similar synthetic polymers applied to soils are largely responsible for the crusts that form when rain follows tillage.

Engineers use the Proctor test to help them compact soil to the maximum density possible.

For most soils, plowing and harrowing every year improves soil tilth in the long run.

Brown and red colors in subsurface horizons are caused by __ in the soil.