A Test of Cultural Treatments Selected to Improve the Chemical and Physical Characteristics of Reclaimed Surface Mine Spoil for the Growth of Loblolly Pine in East Tennessee

Three surface mine spoil areas in East Tennessee were selected for testing the influence of the State reclamation requirements and selected supplementary treatments on the survival and growth of pines recommended for planting on various sites. A high elevation (2,800 feet) test near Caryville, Tennessee, was discarded because of poor survival of white pine and site modification by contractors working in the area.

Fertilizer tests on two established loblolly pine plantations, one on new and the other on old spoil from mining the Sewanee coal seam near Cagle, Tennessee (1,850 feet), indicated that N additions of both 50 and 100 pounds per acre increased growth; response duration appeared to increase when P was added. On the older spoil liming appeared to decrease response to N, especially at 4 tons per acre (State requirement). On new spoil the greatest growth was in plots receiving N with 2 tons of lime per acre; growth was less when lime was added at 4 tons per acre.

Trees on the older spoil were heavily mycorrhizal with Pisolithus tinctorius while trees on the younger spoil were essentially non-mycorrhizal, possibly accounting for greater vigor and growth on the older spoil and the absence of a response to liming. Winter injury (1976-1977) was greater in those trees that grew most rapidly during the previous growing season, especially in the older planting.

On a surface mine near Oliver Springs, Tennessee (2,250 feet elevation), application of a wetting agent and/or a NP fertilizer to the soil appeared to increase growth of trees but survival decreased when either were applied to loblolly pine at planting time. Seedlings inoculated with mycorrhizal fungi survived better and grew more than those not inoculated. Grass density appeared to be the primary factor influencing seedling survival, with high mortality in dense lovegrass.