Effect of fly-ash on metal composition and physiological responses in Leucaena leucocephala (Lamk.) de. Wit.

Plants of L. leucocephala were grown in 100% soil (as control), 100% fly-ash and fly-ash amended with 50% press mud for 80 days, and analysed with respect to plant growth, elemental composition and physiological changes in different parts of the plant. The results revealed that amending fly-ash with press mud enhanced plant growth as well as other physiological responses such as chlorophyll, protein, in vivo nitrate reductase activity compared to 100% fly-ash treated plants. The elements Fe, Zn, Cu and Mn accumulated in larger quantities in plants grown in 100% fly-ash, and followed the order of accumulation Fe > Zn > Cu > Mn. The results of this study indicate that ash amending with press mud may provide more favourable conditions for the growth of this tree species.