A is the layer of the soil profile in which most organic material is found.
Specifically, there are five layers in the soil profile. The first, A layer of organic matter claims the first two inches and contains plant debris. The second, A layer of surface soil comprises the next ten inches down. Below it will be found the third, B layer of subsoil containing aluminum, clay, iron and organic compounds and going down 30 inches; the fourth, C layer of parent rock going down 48 inches; and the fifth, final, R layer of bedrock.
It is the O horizon. The A horizon is the mineral horizon and does include a large amount of organic material but the O horizon contains the most abundant amount of organic matter. The O horizon overlies the A horizon.
The topmost layer of the soil profile, known as the O-horizon or organic layer, would be most affected by weathering and erosion. This layer consists of organic material such as leaves and plant debris, which is more susceptible to breaking down and being carried away by weathering processes like wind and water erosion.
The layer that contains the most organic material in the diagram is the top layer, known as the O horizon or organic horizon. This layer is made up of decomposing organic matter such as leaf litter and other plant debris.
The organic level which is the uppermost level of the soil.
The O horizon contains the most organic matter. The O horizon overlies the A horizon which is known as the mineral horizon. O - organic A - mineral E - elluviation B - illuviation C - parent material R - bedrock This is the order in which you will see standard soil horizons.
The A horizon is the topsoil layer in a soil profile, characterized by high organic matter content and dark color due to decomposition of plant material. It is the layer where most plant roots and soil organisms are found, making it important for nutrient cycling and plant growth.
The top layer of soil, known as the organic horizon or O horizon, contains the most decayed organic material. This layer consists of partially decomposed plant and animal matter, such as leaves, twigs, and dead organisms.
Topsoil
The top layer of soil, known as the O horizon or organic layer, is the most newly formed. It consists of organic material such as leaf litter and is constantly being replenished by decaying plant matter.
The O horizon, also known as the organic horizon, contains the most organic matter in soils. This layer consists of decomposed plant materials like leaves, branches, and other organic debris that have not yet fully broken down.
The A horizon is the most important in forming soil as it contains organic matter and is the top layer where plant roots grow. This layer contributes to soil fertility and structure through the decomposition of organic material.
The top layer of soil, known as the topsoil or A horizon, typically has the highest biological activity due to its organic matter content and availability of nutrients. This layer is where most plant roots, microbial organisms, and soil fauna are concentrated, making it a hub of biological activity in the soil profile.