Q5. EXPLAIN THE PROCESS OF SOIL COMPOSITION.
WHICH FACTORS PLAY BASIC ROLE IN THE SOIL FORMATION? DISCUSS.
Soil is composed of various elements and the environment. The following are the factors which form the soil:.
Climate plays the key role in formation of soil. The change in temperature and moisture, changes the characteristics of the soil. As a result of Increase in temperature the organic elements the proportion of Nitrogen deceases. On the contrary, low temperature would create otherwise properties in soil.
Topography of the land also plays important role in the formation of soil. Thin layer of soil rests on the slops while it becomes thick in depressions because the soil drags on the slops towards the depression but the soil is settled in the depression. On the high level areas, the soil is dry but in the bed of mountains it is marshy because water drains from higher to the tower side and settles there. For Instance, water drains fast from the slops but if the slop is convex, the soil would be marshy and moist. The soil of high topography is salt free but the soil in depression is saltesh because the mineral salts deposit here.
3. VEGETATION AND LIVING ORGANISM:
If the soft elements are embodied in the first layer of the soil, they do not hamper but help in spread of roots of plants. The life of the most of the plants is one year. These plants are died dry and their roots are converted into the food for microbes and remainder parts are eaten by other insects like ants. A microbe, with the combination of other insects, maintains the organic balance in the soil.
4. TIME PERIOD:
Soil composition is a long and complex process therefore, it requires a long period. As a result of change in temperature and moisture, the characteristics of soils also change. In other words, high temperature decreases organic elements and nitrogenous characteristics. On the contrary, low temperature is the cause of creating opposite properties in soil.
5. PARENT MATERIALS:
There are low parent materials which form soil. First the elements obtained by breaking the rocks and which come with the flowing water of rivers and are mixed in soil. The second parent materials, apart from lime stone, are formed due to breaking of fire rocks under the surface of land.
SOIL OF PAKISTAN:
The soil of Pakistan, on the whole, is dry having lower proportion of calcium and the organic elements. The colour of Pakistan’s soil is different in different areas For instance, the colour of Northern Areas is reddish brown while the colour of soil in South is Gray. This soil, due to availability of irrigation water, is higher fertile.
The soil composed of the soil brought by rivers is termed as ‘Khaddar Soil’ and the soil found around the rivers and in mountain bed is sandy. The soil of Thar Desert is dry due to fast winds. In the Southern areas, thin layer of soil is found and this soil is termed as ‘Kallar where canal irrigation prevails.