FOUR LAYERS

There are five soil horizons: O, A, E, B, and C. (R is used to denote bedrock.) There is no set order for these horizons within a soil. Some soil profiles have an A-C combination, some have an O-E-B, an O-A-B, or just an O.

Soils typically have six horizons. From the top down, they are Horizon O,A, E, B, C and R. Each horizon has certain characteristics.

Most soils have three major horizons — the surface horizon (A), the subsoil (B), and the substratum (C). Some soils have an organic horizon (O) on the surface, but this horizon can also be buried. The master horizon, E, is used for subsurface horizons that have a significant loss of minerals (eluviation).

B (subsoil): Rich in minerals that leached (moved down) from the A or E horizons and accumulated here. C (parent material): The deposit at Earth’s surface from which the soil developed.

The simplest soils have three horizons: topsoil (A horizon), subsoil (B horizon), and C horizon.

Topsoil is the upper, outermost layer of soil, usually the top 5–10 inches (13–25 cm). It has the highest concentration of organic matter and microorganisms and is where most of the Earth’s biological soil activity occurs….Evaluation.

Topsoil

A fertile soil will contain all the major nutrients for basic plant nutrition (e.g., nitrogen, phosphorus, and potassium), as well as other nutrients needed in smaller quantities (e.g., calcium, magnesium, sulfur, iron, zinc, copper, boron, molybdenum, nickel).

Clayey soil is very fertile and has a high amount of humus in it as humus can easily mix with clay. Thus the correct option is (C) Clayey soil.

Humus is dark, organic material that forms in soil when plant and animal matter decays. When plants drop leaves, twigs, and other material to the ground, it piles up. This material is called leaf litter. When animals die, their remains add to the litter.

Out of the 8 type of soils found, alluvial soil and forest or mountain soil are found to have high humus content. But the soil that has an equal part of sand, silt and clay i.e. loamy soil is the type of soil which is richest in the humus content.

Generally speaking, clay-rich soils have the largest pore space, hence the greatest total water holding capacity. However, total water holding capacity does not describe how much water is available to plants, or how freely water drains in soil.

Sandy soils

Soil moisture is the water stored in the soil and is affected by precipitation, temperature, soil characteristics, and more. These same factors help determine the type of biome present, and the suitability of land for growing crops.

Mulch, well composted and aged, will help maintain moisture levels in the soil both in ground and in containers. I prefer a pine bark mulch. It helps to keep the pH between 5.5 to 6.5, where most of my plants are happiest. It also helps to break up the native clay found around here.

The soil usually contains a certain amount of available water, so the root system itself is not prone to water deficit. Therefore, when the soil moisture is insufficient, the effect on the above-ground part of the plant is greater than that of the underground part. As a result, the root-to-shoot ratio increases.

Soil moisture is a key variable in controlling the exchange of water and heat energy between the land surface and the atmosphere through evaporation and plant transpiration. As a result, soil moisture plays an important role in the development of weather patterns and the production of precipitation.

Appropriate Soil Moisture Levels by Soil Type

You must know your soil type and soil water holding capacity to make full use of the data you get from the gypsum blocks. Monitoring soil moisture early in the season or during the growing season is important because soil moisture is one of most limiting factors in crop production.

Soil with 5 percent moisture may be dry and 25 percent may be wet. But there are two ways to express percent moisture: Volumetric moisture is where the total volume of the soil, including the pore space, is 100 percent, and the total volume of the water is a percentage of the total volume.

Use a moisture meter. This is the most efficient way to tell if you need to water your yard. Moisture meters feature an easy-to-read dial that indicates if the soil is dry, moist or wet. Simply push the moisture meter into the soil six to eight inches deep and check the reading.