Soils are named and classified based on their horizons. The soil profile has four distinct layers: 1) O horizon; 2) A horizon; 3) B horizon, or subsoil; and 4) C horizon, or soil base (Figure 31.2. 2). The O horizon has freshly decomposing organic matter—humus—at its surface, with decomposed vegetation at its base.

6 Horizons Soils typically have six horizons. From the top down, they are Horizon O,A, E, B, C and R. Each horizon has certain characteristics. O Horizon​ The top, organic layer of soil, made up mostly of leaf litter and humus (decomposed organic matter).

The alluvial soils vary in nature from sandy loam to clay. They are generally rich in potash but poor in phosphorous. In the Upper and Middle Ganga plain, two different types of alluvial soils have developed, viz. Khadar and Bhangar.

Newswise — February 17, 2020 – Alluvial soils are soils deposited by surface water. You’ll find them along rivers, in floodplains and deltas, stream terraces, and areas called alluvial fans. Because floods periodically deposit new sediment at the surface, alluvial soils can have a unique layered look.

the layer in a soil profile below the B horizon and immediately above the bedrock, consisting chiefly of weathered, partially decomposed rock.

C and R represent the master horizons and layers of soils. The capital letters are the base symbols to which other characters are added to complete the designation. Most horizons and layers are given a single capital letter symbol, but some require two.

Complete Answer: (i) Alluvial soil is extremely fertile- It is extremely fertile because it is formed by the sediments transported by rivers and is a mixture of sand, clay and silt. It has a loamy texture and it is rich in humus. It has good water retention and water absorbing capacity.

Alluvial soil contains sand, silt and clay. According to age, the alluvial soil is classified as Bangar (old alluvial) and Khadar (new alluvial). Alluvial soil contains an ample amount of potash, phosphoric acid and lime. The soil is thus suitable for the growth of sugarcane, wheat and rice.

Alluvium consists of silt, sand, clay, and gravel and often contains a good deal of organic matter. It therefore yields very fertile soils such as those of the deltas of the Mississippi, the Nile, the Ganges and Brahmaputra, and the Huang rivers.

C-horizons are glacial or post-glacial material in the Northeast. C layers: are commonly referred to as the substratum. These are layers, excluding bedrock, that are little affected by soil forming processes and have changed very little if any since the time they were deposited.

Dig down deep into any soil, and you’ll see that it is made of layers, or horizons (O, A, E, B, C, R). Put the horizons together, and they form a soil profile. Like a biography, each profile tells a story about the life of a soil. Most soils have three major horizons (A, B, C) and some have an organic horizon (O).

Some of the clay comes from the soil horizons above the Bt horizon. Water moving down through the soil carries very fine clay particles with it. When the downward movement stops, the clay particles are deposited, building up the waxy coatings called clay films. Some of the clay also comes from the weathering of original minerals in the Bt horizon.

C Horizon. The C horizon is mainly made of large rocks or lumps of partially broken bedrock. It is considered the transition layer between soil and parent material. This layer is least affected by weathering as it lies deep within the soil and is inaccessible to the soil-forming agents.

There is no buried soil because the mantle is too thin (22 cm thick). For the profile to have a buried soil, the mantle must be at least 50 cm thick. The buried cambic horizon would be used to classify this soil as an Inceptisol, a Fluventic Haploxerept .