A Closer Look at the Nature of Soil Acidity in Ri-bhoi District, Meghalaya, India

Abstract

Soils of Meghalya in the North Eastern region of India are characteristically acidic in nature. Specific information about the nature of soil acidity would help better management of these soils. The present work was undertaken with the aim to study the different type of acidity and their relationship with various physical and chemical properties of soils in Meghalaya. Soil samples were collected from four depth viz., 0-15, 15-30 , 30-45 and 45-60 cm and six locations having different land use and land form in the Umsning block of Ri-bhoi district, Meghalya. The geology of Meghalaya plateau comprises Precambrian gneissic complex intruded by granite plutons. Results indicated that about 7O%o of the samples were very strongly to strongly acid (pH 4.6 - 5.5), whereas the remaining soils were moderately acid (pH 5.6 - 6.0) in nature. Lower soil pH values obtained with 1 N KCI solution (ApH value ranged from -0.96 to -1.64) compared to the pH with water indicated the presence of considerable amount of exchangeable aluminum. Surface soils were more acidic as compared to sub-surface soils. Exchangeable Al3* content varied from 0.09 to 2.95 cmol (p+) kg-1. Acidity decreased in various landform in the order