EMERGENCE AND GROWTH OF PLANT SPECIES IN COAL-MINE SOIL

Experiments were conducted in the laboratory and greenhouse in Arizona [USA] to evaluate the chemical properties of undisturbed soil, surface-mined coal land (coal mine soil) on the Black Mesa Coal Mine and Gila loam soil; and to study the emergence of 7 plant species in the greenhouse in Gila loam soil and coal mine soil. The pH of coal mine soil (6.2) was lower than the pH of undisturbed soil (7.5) or Gila loam (7.6). The total soluble salts in coal mine soil (3241) and undisturbed soil (4592) were much higher than in Gila loam (378); coal mine soil was lower in total soluble salts than undisturbed soil. The N content of coal mine soil was higher than the N content of undisturbed soil or Gila loam. Emergence percentages for 7 plant spp. grown in coal mine soil were similar to emergence percentages for the same species grown in Gila loam. Alfalfa (Medicago sativa L.), barley (Hordeum vulgare L.) and wheat (Triticum aestivum L. em Thell.) had 84-93% emergence in coal mine soil. Indian ricegrass (Oryzopsis hymenoides Roem. * Shult.), fourwing saltbush (Atriplex canescens Pursh.), yellow sweetclover (Melilotus officinalis Lam.) and winterfat (Eurotia lanata Pursh.) emerged < 35% in coal mine soil and Gila loam. Plant growth data from forage species grown in the greenhouse indicate that coal mine soil has a lower fertility level than does Gila loam soil. When supplied with optimum soil moisture and plant nutrients, coal mine soil produced approximately the same yields of forage from alfalfa, barley and wheat as were produced in Gila loam under the same soil-moisture and fertility conditions.