Growth of Forbs, Shrubs, and Trees on Bentonite Mine Spoil Under Greenhouse Conditions

Abstract

Revegetation on raw bentonite spoil with or without treatments is often more practical than replacing topsoil in areas where it is scarce or nonexistent. The effect of raw bentonite spoil treated with ponderosa pine sawdust on plant survival and growth was compared to other treatments including perlite, gypsum, straw, vermiculite, and no treatment. Plants tested were the drought- and salt-resistant species of fourwing saltbush (Atriplex canescens (Pursh) Nutt.), rubber rabbitbrush (Chrysothamnus nauseousus (Pallo) Britt.), big sagebrush (Artemisia tridentata tridentata Nutt.), common winterfat (Ceratoides lanata (Pursh) Moq.), Rocky Mountain juniper (Juniperus scopulorum Sarg.), Russian olive (Elaegnus angustifolia L.), common yarrow (Achillea millifolium L.), and desert globemallow (Sphaeralcea ambigua Gray). Desert globemallow, fourwing saltbush, and rubber rabbitbrush had substantial growth and survival on sawdust, perlite, and vermiculite treated spoil. The growth promoting effect of sawdust is particularly promising; it is readily available and cost is minimal.