KAWA MULTIMEDIA PUBLICATIONS
Soil composition
Organic matter: Organic matter is the humus obtained when plant and animal matter decomposes. Humus is the black or dark-brown top layer of the soil. It plays a vital role in maintaining soil fertility. It forms 5% of the total soil by volume.
Inorganic matter: This consists of minerals got from the parent rock. It forms about 45% of the soil materials. Minerals like calcium, potassium, manganese, iron, aluminum, sodium and phospherous are common in rocks. These minerals are very important for plant growth.
Soil air: Air exists in pre spaces that are not occupied by water. Air in these spaces is an important component because plant roots and micro- organism such as bacteria make use of it.
Soil water: Water is perhaps the most important factor influencing plant growth. Soil water varies from one soil to another depending on whether the soil is saturated with moisture.
Soil organisms: Very tiny plants and animals live in the soil together as soil organisms. Among these organisms are bacteria. Bacteria play a vital role in the soil. Its prime function is the conversion of nitrogen from the air into nitrates and ammonium compounds which are used by plant roots in solution. Besides, bacteria play an important role in the decomposition of organic matter into humus.
Inorganic matter: This consists of minerals got from the parent rock. It forms about 45% of the soil materials. Minerals like calcium, potassium, manganese, iron, aluminum, sodium and phospherous are common in rocks. These minerals are very important for plant growth.
Soil air: Air exists in pre spaces that are not occupied by water. Air in these spaces is an important component because plant roots and micro- organism such as bacteria make use of it.
Soil water: Water is perhaps the most important factor influencing plant growth. Soil water varies from one soil to another depending on whether the soil is saturated with moisture.
Soil organisms: Very tiny plants and animals live in the soil together as soil organisms. Among these organisms are bacteria. Bacteria play a vital role in the soil. Its prime function is the conversion of nitrogen from the air into nitrates and ammonium compounds which are used by plant roots in solution. Besides, bacteria play an important role in the decomposition of organic matter into humus.