H.V. RUDRAMURTHY, Y.P. SHILPASHREE AND E.T. PUTTAIAH
Abstract
The soils under both Flue Cured Virginia (F.C.V) tobacco and sugarcane land use systems, belonged to the soil order Alfisols and the magnitude of different forms of soil acidity was in the order of total potential acidity >pH dependent acidity > total acidity > hydrolytic acidity > extractable acidity > exchangeable hydrogen >exchangeable aluminum > non-exchangeable aluminum. In general soil under F.C.V tobacco recorded higher amount of all forms of acidity than the soil under sugarcane and this could be attributed to the lowest soil pH in the soil under former land use system and higher soluble salt concentration in the later land use system. Lime requirement of soil under F.C.V tobacco was comparatively more than the soil under sugarcane. Positive and significant correlation among different forms of soil acidity with exception to non-exchangeable aluminium suggested the possible existence of a dynamic equilibrium among different forms of soil acidity and loss of one form of acidity would be replenished by other forms. Among the soil properties studied only the soil reaction and exchangeable acidic cations were significantly correlated with different forms of soil acidity. Soil reaction was negatively and exchangeable acidic cations were positively correlated with different forms of soil acidity.