Essay On Soil Microorganism

Soil and its origin

Soil is the unconsolidated mineral or organic material which forms the outer loose layer of earth surface that serves as a natural growth medium for land plants. Soil originates from disintegrated rock materials. These rocks could be igneous, sedimentary or metamorphic. The simultaneous and continuous weathering of rocks by physical and chemical elements results in formation of parent materials. The action of biosphere (Living components of soil) on the parent materials forms soil.

Components of soil

Soil has 5 major components:

1. Mineral matter: This is formed by the disintegration or decomposition of rocks which may be caused by the action of water, ice, frost, or temperature changes, or by plant or animal life.

2. Water:

The soil has an enormous number of living organisms which include plant animal and microorganism. These organisms are naturally active during certain times of the year. Most are active when the soil is warm and moist, like during late spring and early summer.

Classification of soil organisms Soil microorganisms can be classified based on physiology or nutritional requirement, mode of respiration, origin and body size

A. Physiological/Nutritional requirement Classification: Microorganisms need food as sources of energy to enable them carry out their activities, for growth and multiplication. Microorganisms differ in their nutrition requirements, whereas some organisms can use the same source of food as carbon and energy, others require different sources as carbon and energy. On this basis microorganisms are divided into

1.Autotrophs/Lithotrophs: These are organisms that can use CO2 as the sole source of carbon. Based on the source of energy autotrophs are further classified as;

i. Photoautotrophs/Photolithotrophs: These are organisms deriving their energy from sun through the process of photosynthesis. Such organisms contain a pigment known as chlorophyll which enable them convert CO2 to carbohydrate in the presence of sun energy eg