Black soil is not suitable for cotton growing

Dynamic metamorphism is caused by high temperature.

Sedimentary rocks are the hardest ones.

1. Soil conservation is the process of protecting the soil from erosion to maintain its fertility.
2. The methods that are widely practieed for conserving soil are afforestation, controlled grazing, construction of dams, crop rotation, strip faming contour ploughing, terrace farming, checking shifting cultivation, wind break, etc.

1. The rocks are the solid mineral materials forming a part of the surface of the earth and other similar planets.
2. The earth's crust is composed of rocks.
3. A rock is an aggregate of one or more minerals.
4. Rock is an important natural resource and is found in solid state.
5. It may be hard or soft in nature.
6. They may occur either in the form of elements or compounds.

1. The igneous rocks are formed by the solidification of molten magma.
2. These rocks are also called as the 'Primary Rocks' or 'Parent Rocks' as all other rocks are formed from these rocks.

Classification of soils:
Soils are classified on the basis of their formation; colour, physical and chemical properties. Soil is classified into six types.
1. Alluvial soil:
(i) These soils are found in the regions of river valleys, food plains and coastal regions.
(ii) It is the most productive of all the soils. Suitable for cultivation of sugarcane, jute, rice, wheat and other food crops.
2. Black soils:
Formed by withering of igneous rocks: Black soil is clay in nature. it is retentive of moisture. It is ideal for growing cotton .
3. Red soils:
(i) Formed by weathering of metamorphic and crystalline rocks.
(ii) The presence of iron oxide makes this soil brown to red in colour.
(iii) Found in semi-arid regions. It is. not a fertile soil. It is suitable for millet cultivation.
4. Mountain soils:
(i) Found over the slopes of mountains.
(ii) Soils in these regions are thin and acidic.
(iii) However characteristic of soil differs from region to region based on the altitude.
5. Desert soils:
These are sandy soil found in the hot desert regions.
(i) These soils are porous and saline.
(ii) Since it is infertile, agriculture in these soils is not so successful.

According to the mode of formation the rocks are classified into three as follows
1. Igneous Rocks
2. Sedimentary Rocks
3. Metamorphic Rocks
Igneous Rocks:
1. The igneous rocks are formed by the solidification of molten magma.
2. These rocks are also called as the 'Primary Rocks' or 'Parent Rocks' as all other rocks are formed from these rocks.
3. Igneous rocks are of two types. They are
Extrusive Igneous Rocks.
Intrusive Igneous Rocks.
Sedimentary Rocks:
1. The sedimentary rocks are formed by the sediments derived and deposited by various agents.
2.Due to high temperature and pressure, the undistrubed sediments of long period cements to form sedimentary rocks.
3. These rocks consist of many layers which were formed by the sediments deposited at different periods. As it consists of many strata, it is also known as 'stratified rocks.
4. The three types of sedimentary rocks are
i) Organic Sedimentary Rocks
ii) Mechanical Sedimentary Rocks
iii) Chemical Sedimentary rocks
Metamorphic Rocks:
When Igneous and sedimentary rocks are subjected to high temperature and pressure, the original rocks get altered to form a new kind of rock called metamorphic rocks.
Metamorphism is of two types
1. Thermal Metamorphism
2. Dynamic Metamorphism