Soil is made up of distinct horizontal layers;They are; 1.O HORIZON;The top organic layer of soil,made up of mostly of leaf litter and humus . 2.A HORIZON;The layer called top soil,is present below o horizon .seeds germinate and plants grow in this dark layer.It is made up of humus mixed with mineral particles. 3.E HORIZON;This layer is light in colour.it is made up of mostly sand and silt.,and lost most of its minerals and clay as water drips through the soil 4.B HORIZON;Also called sub soil.it contains clay and mineral deposits like iron and alluminium oxide. 5.C HORIZON;Also called regolith;it consists of slightly broken up bed rock. 6.R HORIZON;The unweathered rock layer that is beneath all the other layers.