Chemical effects of wood ash on plant growth in tropical acid soils

A greenhouse study was conducted to compare chemical effects of wood ash and CaCO3 on the growth of rye grass (Lolium perenne L.) in three tropical acid soils (Kandiudult). Amendments were applied at rates to attain target pH values of 5.5, 6.0 and 6.5. Generally, plants grown on ash-amended soils showed higher biomass production than did plants grown on lime and control treatments. After wood ash application, plants benefited from Ca and K supplementation, the synergy K-NO−3 and from changes in soil chemistry similar to lime application: higher ECEC and reduced Al and Mn toxicity. Therefore, wood ash appeared at the same time as a neutralizer of soil acidity and as a supplier of nutrients for tropical acid soils.