Tall fescue production and nutrient status on southwest Virginia mine soils

Tall fescue (Festuca arundinacea Schreb.) is a hardy grass species commonly used in surface mine reclamation and soil conservation. This study documented changes in fescue production (five growing seasons) and nutrient status (three growing seasons) as influenced by spoil type and various amendments. In Exp. I, fescue growth and nutrient status on five mixes of fertilized sandstone (SS) and siltstone (SiS) spoils were compared. A 2:1 SS/SiS control and treatments of 112 Mg ha^-1 sawdust, native topsoil, and 22, 56, 112, and 224 Mg ha^-1 municipal sewage sludge were compared in Exp. II. Standing biomass was measured in 1982-1984 and 1986 and tissue nutrient levels were measured in 1982-1984. High SiS spoils inhibited initial biomass production in Exp. I, but parent material effects diminished with time. All spoil mixes maintained adequate fescue production for five growing seasons, primarily due to small annual N additions (56 kg ha^-1). In Exp. II, highest yields were maintained on ≥ 56 Mg ha^-1 sludge treatments. Fescue production declined consistently through 1984 in all other treatments, probably due to N stress. Fescue production was highest the second year (1983) in all treatments of both experiments, but dropped sharply in 1984. Overall results indicate N was most limiting to production in the short term, but P becomes limiting over time. Sludge-amended soils supported higher N, P, and cation tissue concentrations. Total P uptake appeared to be limited by low N levels, even when adequate soil P was available, potassium uptake rates greatly exceeded K fertilizer applications. Heavy metal uptake was not a problem, even in very high sludge treatments. Sludge-amended mine soils were superior to both native topsoil and inorganically fertilized spoils in their ability to sustain long-term fescue production without periodic augmentation.