Changing rock or organic matter into the soil grains due to several factors, among others, the following:
1. amplitude high temperatures accelerate weathering.
2. water flow will accelerate weathering.
3. plant roots through the soil break down rock.
4. animals will break, especially animal sheltering in the soil
5. pile of organic waste will form the ground.
The composition of the soil are as follows:
1. minerals: minerals derived from weathering of rocks physical and chemical (45%).
2. air (20% - 30%).
3. organic material: material derived from the remains of living things (5%).
4. water (20% - 30%).
Soil profile is as follows:
1. O Horizon: a soil layer consisting of organic elements, lush nature, found in areas that have not been touched by humans.
2. A horizon (top soil or top soil).
b. thickness between 10-30 cm
c. a layer of fertile
d. potential for plant
3. Horizon B (bottom soil or sub soil)
a. brighter color
b. more dense than the layer above it
c. thickness of 50-60 cm
d. often called rock or hard soil
e. activities of living bodies began to decrease
4. Horizon C (terlapuk host rock or regolith)
a. color is similar to the host rock
b. can still be penetrated by plant roots
5. Horizon D (host rock or bedrock)
a. color is reddish or gray
b. difficult to penetrate the roots.