Study On Fly Ash And Agricultural Residues Used As Media Of Tall Fescue Culture

Our country is one of some countries taking coal as the main energy in the world. Fly ash as a by-product of coal combustion has large output and rich resources, but low utilization rate, at present. Lots of domestic and abroad studies had shown that fly ash is a source of readily available plant macro and micronutrients, and may improve the physical and chemical properties. Sawdust as the residue of wood processing and rice husk as the residue of rice processing, both of them have large resources needed reasonable recycled urgently. Peat can improve physical and chemical properties of media and promote plant growth. To explore the characteristics of four substrates in the compound media and the best proportion of the four soilless substrates for Tall Fescue growth, fly ash, peat, sawdust, rice husk were mixed in different proportions in a simplex-lattice design{4,2}. The analysis results of the compound substrates chemical properties, Tall Fescue growth and physiology showed that:(1) fly ash can increase pH, EC and concentration of extractable phosphorus and Cu in the mixture, and promote tiller and growth of biomass, but high rate application (60%) will inhibit germination, reduce growth of plant height and content of Chlorophyll a, and aggravate yellow rate. Peat can increase concentration of extractable potassium, Fe and Mg, and promote tiller and growth of plant height and biomass when application rate reaches 40%. Rice husk can increase EC and concentration of extractable potassium, to some extent, sawdust also can improve Tall Fescue growth. (2) The studies on Tall Fescue growth demonstrate that the compound media can provide a suitable environment for Tall Fescue grow, and some treatments (T2,T5,T8) perform better than soil (CK). The differences of nutrients exist among all the treatments, but that is not the constraints affecting Tall Fescue growth. The plant in the soilless media grew better than that in soil at the beginning, but the turf quality in most of treatments declined obviously compared with that in soil at the interim and the end. In physiology, compound media can change photosynthetic efficiency of Tall Fescue by affecting its response of light. The results of chlorophyll fluorescence parameters confirmed that photosynthetic efficiency of Tall Fescue in some treatments higher than that in soil. (3){4,2} simplex lattice design was adopted to study relationship between the formula of fly ash, peat, sawdust, rice husk and dates to full coverage. Scheffe mathematical model was established, too. The best proportion of the four soilless substrates for the minimum days to full coverage and the scope of the various substrate composition for different conditions were obtained by computer simulating, which combining with the relationship between substrate formula and cost of compound media can provide directions for practice.