Release of soluble aluminium in soils under submerged conditions and its effect on rice

Abstract

A study has been made of the extent of aluminium toxicity in relation to other important characters in the acid Rice soils of Kerala with a view to evolving suitable ameliorative measures. The submerged wet-land rice soils of Kerala showing a pH value of less than 6.0 were found to contain appreciable amounts of exchangeable aluminium. The aluminium saturation of the total and effective CEC of these soils were also very high and above the critical limits for rice. Flooding of these soils in water resulted in a rise in pH and EC, as well as water soluble and exchangeable iron. Peak values for these parameters were obtained by 20-30 days of flooding, after which the pH remained steady while EC and iron showed a decreasing trend . Water soluble and exchangeable aluminium, on the other hand, registered a significantly lower content after the 6th day and the trend continued till the 30th day.