[Effect of fly ash-filtered mud mixture on soil properties and radish yield and quality]

Based on pot culture experiment, the effect of fly ash-filtered mud mixture on soil biochemical properties, radish yield and its quality, and heavy metal accumulation in both soil and radish was examined. The mixture was made by mixing fly ash and filtered mud in proportion 1:1(w/w) and adding small amount of inorganic fertilizer. Its Cd, Pb, Cr, As and Hg contents were much lower than those requested by state control criteria. After applying this mixture in a definite amount, no significant accumulation of heavy metals was found in both soil and radish, the pollution index of heavy metals was < 1, the quantities of soil bacteria increased notably, and the activities of soil urease, phosphates and cellulosase also raised significantly. The application of the mixture promoted radish growth and its development and metabolism. The reducing sugar and vitamin C in radish also increased markedly. The results indicated that the use of adequate amounts of the mixture did not cause any obvious heavy metal pollution in both soil and radish, but could improve soil fertility, and raise radish yield and its quality remarkably.