Soils of the Indo-Gangetic Plains: a pedogenic response to landscape stability, climatic variability and anthropogenic activity during the Holocene

Abstract

Bound by the Himalaya in the north and the Craton in the south, the Indo-Gangetic Plains (IGP) is one of the largest fluvial plains of the world. The IGP is monotonously flat with a spread of surface soils in hot arid conditions of Rajasthan in west to per-humid conditions in West Bengal. The soil-geomorphology of the IGP detailed during the last few decades is useful in determining the interrelationship among the pedogenesis, the climate, and the landscape evolution during the Holocene. These studies demonstrate that the IGP soils developed on five geomorphic surfaces with varying degree of development. Soils occurring on older geomorphic surfaces (>2.5ka) are polygenetic with a distinct record of climatic changes and neotectonics.The present synthesis is based on recent developments in pedology achieved through macro- and micromorphology, clay mineralogy, pedogenic calcrete, and polygenetic pedogenic features of the IGP soils. A critical evaluation of the IGP soils has helped to comprehend the subtle nuances of the pedogenic processes that were also influenced by anthropogenic activities and cultivation over this vast agricultural tract during the Holocene. We provide state-of-the-art information on the pedology, polygenesis, and soil degradation (natural and anthropogenic) over the last 10ka. The review has potential as a reference for critical assessment of the pedosphere for health and quality in different parts of the world. In addition, it facilitates developing a suitable management practices for the food security in the 21st century.