Revegetation of Waste Fly Ash Lagoons II. Seedling Transplants and Plant Nutrition

Abstract

As an alternative or in addition to direct seeding, container-grown transplants provide a means of economically and rapidly revegetating waste fly ash lagoons through the expeditious establishment of vegetation islands. Survival and growth of Enchylaena tomentosa and Nitraria billardierei transplants were largely dependent on the size of the root volume at transplanting. Growth response of both species in fly ash increased significantly as transplant container size increased from 110 ml to 800 ml. Fly ash incorporated into the potting mix during the containerised stage of growth generally reduced plant growth and survival following eventual transplantation. Gradual hardening of Enchylaena tomentosa seedlings to increasing concentrations of fly ash in the potting mix (25 to 50 to 75% fly ash), however, improved immediate survival following transplantation, into pure ash.