Is weathering essential as a pre-requisite in the formation of soils? Why?
Yes, weathering is essential as a pre-requisite in the formation of soils.
Soil formation or pedogenesis depends first on weathering. The weathering mantle (depth of the weathered material) is the basic input for soil to form. Weathering processes are responsible for breaking down rocks into smaller fragments and preparing the way for the formation of regolith and soils.
The weathered material is first colonised by bacteria and other plant bodies like mosses and lichens. Dead remains of organisms help in humus accumulation, and gradually a mature soil forms as a complex mixture of mineral and organic products. Without weathering, there would be no raw material for soil formation to begin.
Explanation
The textbook explicitly states that 'Soil formation or pedogenesis depends first on weathering' and that the weathering mantle is 'the basic input for soil to form.' Weathering breaks rocks into smaller fragments, creating regolith which serves as the foundation for soil. The context also explains the subsequent process where weathered material is colonised by organisms, leading to humus accumulation and eventually mature soil formation.