Vol. 12, Issue 7 (2023)

Author(s):
Amrutha KK, Beena VI and Geetha P

Abstract:
The acidity characteristics of acid sulphate soils in the Kole lands of Thrissur district of Kerala were studied in detail by collecting surface soil samples at 0-30 depth from 25 locations, including Puzhakkal, Mullessery, Andhikkad, and Cherpu blocks. Around eight% of the soil samples fall under ultra-acid category (pH <3.5) and 20% come under extremely acidic (pH 3.5-4.5) category. Potential acidity showed higher values compared to other acidity fractions. It ranged from 5.8 to 34.4 meq 100 g^-1, followed by pH dependent acidity, which ranged from 5.17 to 26.92 meq 100 g^-1. Contribution of different fractions of acidity towards potential acidity showed that around 60.71 to 94.19% of acidity is contributed by pH dependent acidity, followed by exchangeable acidity (5.81-39.29). Active acidity showed the least contribution towards potential acidity and it accounted for 0.06-2.71%. Each acidity fraction is important in accessing the acidity in acidsulphate soil, and this paper aims to reveal the importance of the estimation of operationally defined acidity fractions such as actual acidity, potential sulfidic acidity, and retained acidity for the assessment of acidity hazards in acidsulphate soils and thereby their management.