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FASF 101

Instructor:

Cliff Imasuen

i. Parent material: The type of materials, that is structure, texture, and mineral composition present in the parent rock will also determine the type of soil formed. Parent materials are important in the following ways;- Determining the properties of the soil e.g coarse, grain soils are formed from granite or gneiss- Coarse parent materials form coarse-textured and well-drained soils.- Rocks containing calcite, feldspar will produce deep heavy soils like clayey soils.- Quartz, hornblende and mica will form poor soils like sandy soils.- Shale and limestone parent materials yield soils that are fine-textured, poorly drained and with high mineral content.

ii. Climate: This the average weather condition of a place over a long period of time.

Climatic factors include the following:- Rainfall- Temperature- Wind- Relative humidity- Pressure

Rainfall: Helps in the dissolution of chemicals from the parent materials and also in transporting broken down materials.

Temperature: Effect of temperature leads to expansion and contraction of rocks. Rock mineral with low expansively will break away to form soil. Also rock holes may retain water which freezes up at night and melts during the day, leading to disintegration of rocks.

Wind: It can carry materials which collide with rock surfaces leading to breaking of rocks into tiny particles.

Relative humidity: This can supply moisture thereby encouraging the breaking of rocks particles into soil.

Pressure: This can lead to the breaking of large rock particles into tiny soil particles.

iii. Topography: Relief or topography refers to the surface features of the earth crust such as hills, valleys or flat land. It may also mean the shape of the land in relation to the underlying rocks of the earth surface. The effect may include the following:- The shape of the land affects the movement and amount of water in the soil.- Hilly and sloppy surfaces support erosion and encourage soil formation. A flat land exposes the surface to equal environmental factors and therefore delays soil formation.iv. Living Organisms: This refers to the activities of plants, microbes, rodents, man. Their effects will help to encourage soil formation in the following ways;Animals such as rodents, earthworms, termite, etc burrow into the rocks and living the holes or cracks in the rocks, they exert pressures which break off fragments of rock. The activities of man during farm operation and construction contribute to the breaking down of rocks into smaller particles especially when ploughing machines are employed.The root of higher plants exert prying effect on rock to cause break down Also plan’s root exude certain substances which may cause dissolution of rock minerals, hence resulting in soil formation.v. Time: This constitute an important factor to soil formation, the breaking down of rocks and decomposition of organic materials takes some time, the time may be short or long. Time determine the age of the soil, that is, a young or an old soil. Young soils have poor water-holding capacity, mineral content and life sustenance. Oil soil are rich in everything because all the factors of like climate, parent material, topography and living organisms take time to register the effects on the soil formed. Also it takes time for plants to decay and become part of the soil.

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