soil

soil soil is defined as the thin surface of the uppermost layer of the earth crust on which plants grow COMPOSITION OR COMPONENTS OF THE SOIL The soil is made up of five components which are: (I)inorganic or mineral matter (II)soil water (III)soil air (V)Living organisms Mineral or inorganic matter,organic matter,water and air are collectively referred to as physical components of the soil while living organisms are referred to as biological components of the soil. MINERAL OR INORGANIC MATTER The mineral matter represent small rock fragments of the soil,it forms the bulk of about 45% of total volume of the soil,it consists of gravels,stones,sands,silt and clay. IMPORTANT/EFFECT OF MINERAL MATTET ON AGRICULTURE 1.It forms the solid part of the soil which provides support for plants. 2.Mineral matter is the main source of plants nutrients such as nitrogen,calcium, magnesium,iron.etc 3.its presents the home of abital of all soil living organisms. 4.Its holds water and air for both plants and animal activities. 5.Mineral matter moderating effects on soil temperature. 6.its also affects soil porosity. ORGANIC MATTER The organic matter represent the remains of the decomposition of plants and animals.its about 5% of the total volume of the skill leaves,roots of plants,the residue of crops,animal dung,etc.when they are decomposition on the soil decay to form a dark colour on the upper parts of the soil.this becomes organic matters which is also called humus.