Distribution Study of the Different Forms of Soil Acidity and Available Nutrients in Upper Brahmaputra Valley Zone (UBVZ) of Assam

Soil acidity is a major constraint that affect crop growth and production in larger aspect. The objective of the study is to characterize different forms of soil acidity components in relation to the soil properties. So, 14 georeferenced soil samples were collected from Jorhat and Sibsagar district of Assam. The soils of UBVZ of Assam were highly to moderately acidic (pH range 4.27 to 5.34) with sandy loam to silty clay loam in texture and high content of organic carbon ranged from 0.72 to 2.59%. The exchangeable Ca and Mg value ranged from 1.40-2.64 cmol(p+)/kg and 0.7-2.0 cmol(p+)/kg, respectively with CEC from 7.8 to 14.2 cmol(p+)/kg and BS from 25.03 to 43.76%. Correlation between soil physico-chemical properties and soil acidity components revealed that OC had positive correlation with total acidity (r = 0.638*) and exchange acidity (r = 0.551*) while BS% had negative significant correlation with total acidity (r = -0.540*). Exchangeable calcium was significantly correlated with total acidity (r = -0.751**), exchange acidity (r = -0.610*) and exchangeable H+ (r = -0.557*) while Ex Mg had significant negative correlation with exchangeable H+ (r=-0.596*). Deficiency of various nutrients in soil can hinder the yield productive prospects in future. So, we must think of the holistic approach to meet the present need of the nutrients.