Ecology, Environment and Conservation Paper

DYNAMICS OF ACIDITY COMPONENT OF THE SOILS ASINFLUENCED BY LIMING IN UPPER BRAHMAPUTRA VALLEYZONE OF ASSAM, INDIA

M.M. Devi, D. Bhattacharyya, K.N. Das, D.K. Patgiri, K. Kurmi, H. Saikia and K.D. Devi

Abstract

An incubation study was conducted to investigate the effect of lime (CaCO3)on the acidity components inUpper Brahmaputra Valley Zone (UBVZ) of Assam. Fourteen(14) geo-referenced soil samples were collectedfrom Sibsagar and Jorhat districts of Assam. Soils were treated with 3 different doses of lime viz. 10 per centLime Requirement (LR10), 25 per cent Lime Requirement (LR25) and 50 per cent of Lime Requirement(LR50) and initial properties were recorded before liming. Samples were incubated in laboratory at differentperiod of time viz. 15, 30, 60 and 90 days after liming (DAL) with moisture content at Field Capacity (0.33bar). At four different intervals, soils were analysed for soil acidity components viz. total acidity, exchangeacidity, exchangeable Al3+ and exchangeable H+. The soil of Upper Brahmaputra Valley Zone (UBVZ) ofAssam were highly acidic to moderately acidic, sandy loam to silt loam in texture with high OC contentranged from 0.72 to 2.59%. The Cation Exchange Capacity (CEC) value ranged from 7.8 to 14.2 cmol (p+)/kg. Application of lime brought about mark decreased in acidity components viz. total acidity, exchangeacidity, exchangeable aluminium and exchangeable hydrogen. Soil acidity components recorded highestdecreased at 90 DAL @ LR50 and decreased started from 15 days onwards. The findings of the investigationshowed that liming @ LR10 was found effective in reducing soil acidity. The residual effect of lime wasfound persisting till 90 days. However, the magnitude of lime was increasing with increase in applicationof lime@ from LR10 to LR25 and to LR50.