The factors of soil formation which controls the formation of soil are as follows. They are passive factors and active factors. The first three are in the passive group. The passive factors are:

1. Parent Rock: A soil is derived from the parent rock material containing different material. The parent rock gets broken into tiny pieces and is decomposed slowly by mechanical, chemical and biological mineral particles of the soil. The parent rock also influences the rate of soil formation, the chemical composition, colour, texture, structures, mineral content and fertility.

2. Relief: The topography of an area affects the degree of erosion of the parent rocks material and the rate of surface runoff off the water. Thus the relief affects directly or indirectly the process involved in the soil formation. There is less infiltration of water on steeper slopes which retards the soil forming process. In addition rapid runoff on steep slopes often erodes their surface faster than soil can develop. It is because of this that the mountainous topography develops coarse thin and barren soil and the plain areas have rich well developed fertile soil.

3. Time: The soil forming process is very slow. A well developed soil results as an end product of physical, chemical and biological processes operating collectively for a very long period of time.

Active factors:

4. Climate: It is by for the most important factor in the sense that over a long period of time it not only tends to reduce the difference caused by the parent material but also influences biological activities within the soil. Due to this factor two different parent material may develop the same type of soil in one type of climatic region. For example granite and sandstone have developed into sandy soil in dry Rajasthan desert. On the other hand two different types of soil may develop from the same parent rock in two climatic regions. For example the crystalline granite has developed laterite soil in monsoon regions and non-laterite soil in subhumid-regions.

5. Plant and animal organism: Plant and animals play an active role in transforming parent material into a matured soil. Dead plants and animals contribute to the organic content of the soil. The process of decay added by bacterial action transforms organic matter into humus.