Restoration of grassland after magnesian limestone quarrying.
Abstract
Dactylis glomerata, 18 other grass spp. and 5 legume spp. were grown in mixtures and in pure stands on magnesian limestone waste from 1971. In the greenhouse, D. glomerata yields were increased by application of N, K and peat, and there was a positive interaction between N and K. Yield responses to 20:10:10 NPK complete fertilizer were linear at rates from 0 to 2500 kg/ha; a combination of complete fertilizer (NPK) with organic amendment of softwood bark or sewage sludge gave good establishment and sustained growth. The legume spp. showed yield responses to 600 kg 12:18:12 NPK high phosphate fertilizer/ha but not to seed inoculation. Agrostis stolonifera, Festuca rubra, Dactylis glomerata, Lotus corniculatus and Trifolium repens were likely to be most effective in long-term reclamation. It was concluded that permanent grassland can be established on magnesian limestone wastes without recourse to deep topsoil amendment.