Top soil: It is the upper most layer of the soil and is best for agricultural purposes as it is high in organic matter and is of fertility and has a long life. If it gets eroded and being carried away over a period of time due to natural physical forces of water and wind, it will fill in the drainage channels (Rees, 1992). Soil erosion results in the reduction of productivity of agricultural land and it also contribute in the pollution of adjacent water bodies, lakes and wet lands.
Tests to evaluate the richness of soil:
i) Clay soil: It is that soil which if kept in hand will hold its shape, and when poked it will remain as a stubborn object in its original form.
ii) Sand: It is that soil which will flow out of hand as soon as the hand will be opened.
iii) Loam: It is the soil which is good for agricultural purposes as it contains a lot of decayed plants and other remains and does not contain too much clay and sand in it. If it will be kept in hand, it will hold its shape and when poked slightly, it crumbles.
Implications of Urbanization:
i) Socioeconomic impacts:
ii) Environmental impacts:
iii) Policy Implications:
iv) Bulk density:
It is a weight of soil in a given volume. It tends to increase with compaction and increases with depth. The growth of root is restricted if the soil has a higher bulk density than 1.6g/cm3.