The world beneath your feet : a closer look at soil and roots / by Mark Mϋller.

A booklet about soil, soil ecology and soil conservation produced by the Iowa Living Roadway Trust Fund and the Iowa Department of Transportation.

The teaching of conservation : Iowa elementary teachers handbook, 1949

This handbook gives information to Iowa elementary teachers on how to teach conservation to students. Units covered are soil, wildlife, nature, mineral resources, forests, water, farming and legumes and grasses.