Time after Mine Land Reclamation: Influence on Soil Health.

Soil health is defined as the continued capacity of soil to function as a living ecosystem that sustains plants, animals, and humans. Reclaimed minesoils are highly disturbed soils with compromised soil health. With time, minesoil properties and functions may change and possibly improve soil health. A potential use of minesoils includes agricultural production. However, how much time is needed for minesoils to regain functionality, productivity and health?

The objective of this research is to measure soil properties, plant diversity and productivity in minesoils of different ages and relate them to soil health. Our hypothesis is that time since reclamation will influence soil properties related to soil health, and their potential for agricultural production.

Three West Virginia minesoils were selected for this study based on time since reclamation, New Hill-14 years, WV01-11 years, and WV00-1 year. All sites were similarly reclaimed (backfilled, 7.5 cm topsoil, graded) and planted to mixed grass-legume pastures. Eighteen soil samples were taken at a depth of 15 cm. Soil bulk density, wet and dry aggregation, pH, organic matter, and bioavailable nutrients (phosphorus, magnesium, potassium) were measured. At the same 18 points, plant biomass and diversity were determined.

Preliminary data indicated bulk density ranging between 1.52 and 1.67 Mg m^-3, however no statistical difference was observed. Dry aggregation showed predominance of large aggregates (>16mm); average sizes were 13.9±4.3mm for New-Hill, 17±4.8mm and 19.6±3.7 for WV00 and WV01 respectively. Sites differ in predominance of grasses, legumes and forbs. The highest biomass productivity was measured in New-Hill (2.2±0.4 Mg ha^-1), followed by WV01 (1.9±0.5 Mg ha^-1) and WV00 (1.2±0.2 Mg ha^-1).

Based on our preliminary data, an increase in biomass productivity and plant diversity was observed for New-Hill, which may indicate soil health improvement over time and agricultural production potential. Additional measurements should be made to confirm our findings.