Besides interactions of all these soil forming factors like topography × parent material, climates × biosphere etc. The process by which soil is formed as a result of interactions over time between parent material (rock), climate, topography, and organisms. The earth’s surface contour is called topography or relief. P. Buurman. Ants, termites and rodents carry material from lower depths upwards and even to the surface. disintegration (physical) and decomposition (chemical) of rocks and minerals; ADVERTISEMENTS: (ii) The development or the formation of true soil by some soil forming factors and pedogenic processes. where, b = biosphere (vegetation, organisms and man), and others are same as Dokuchaiev’s equation. Jenny then emphasized that a soil property is determined by the relative influence of all these factors. The parent material has been defined by Jenny as, Parent materials influence soil formation with the intensity of weathering, the nutrients they contain for the utilization by the plants and the particle sizes they contain (sandstones- sandy; conglomerates-rocky; shales-clayey).
weathering is considered as a destructive one and helps to change the consolidated rocks and minerals into unconsolidated material (parent material) whereas second phase of soil formation is considered as a constructive process and develops the soil profile. An approximate age of soil can be assessed by radio carbon dating, pollen analysis or carbonate carbon in Caliche layers etc. The activity of living plants and animals and the decomposition of their organic wastes and residues have profound influence on soil formation as well as soil profile development. influence the soil formation.Weathering just started, but much of the original material is still un-weathered. C. Soil Formation on Sedimentary rocks. On the other hand, humid and cool condition (temperature climate condition) prevailing in the Northern districts (Darjeeling, Jalpaiguri, Coochbehar) of West Bengal also favours the formation of other groups of soil podzols, forests soils etc. The fundamental processes along with some important specific pedogenic processes and reactions are given in table 10.1. Decomposition arrives at a final stage, and only the most resistant minerals to weathering have survived. Horizons tend to develop faster under warm, humid, forested conditions where there is sufficient water to move colloids. also influence the soil formation. Degradation is an evolution, different from natural evolution, related to the local climate and vegetation. disintegration (physical) and decomposition (chemical) of rocks and minerals; (ii) The development or the formation of true soil by some soil forming factors and pedogenic processes. However, the properties of well- developed soils will also be greatly influenced by the parent material. Soils of these regins exhibit only slight organic matter accumulation. Prev: soil fluction Next: soil horizon Glossary Search . Topography influences soil formation primarily through its associated water, .temperature, soil erosion and micro-climate relations. Out of total rainfall or precipitation, a part of it percolates downward and a portion of it is lost as surface runoff. The micro-organisms play their role in the decomposition and transformation of organic matter. The less developed a soil is, the greater will be the effect of parent material on the properties of the soil. soil formation definition in English dictionary, soil formation meaning, synonyms, see also 'soil',soil',acid soil',alkali soil'. Lacustrine deposits consist of materials that have settled in the stagnant water of lackes. They also contribute biomass to the soil. Factors which cause delay in soil formation are extremes of cold and dry climate, impermeable and consolidated parent material (incomplete weathered rocks and minerals) high in lime and very steep slopes. Clay formation is favoured by parent materials containing a high percentage decomposable dark minerals and less quartz. During runoff, the various soluble and insoluble materials are deposited at the base of the slope (at the foot hills). (i) Addition of water, organic and mineral matter to the soil, (iii) Movement or translocation of soil materials from one point to another within the soil profile, and (iv) Transformation of the mineral and organic matter in the soil and formation of definite layers or horizons. Calcification and Gypsification are the forming processes of arid and semi-arid regions and refer to the formation and accumulation of calcium carbonate and gypsum respectively. The first phase of soil formation i.e.
(c) Copyright Oxford University Press, 2013. Climate is perhaps the most important factor that can influence the soil formation, climate affects soil formation directly (through the supply or water and heat) and indirectly (different types of flora and fauna forming different organic matter of different natures).
It is a most important initial soil material that determines the soil profile development as well as physical properties of soils. The basis or fundamental pedogenic processes bring about certain specific processes by means of a variety of reactions like Calcification.