All Soil Types Explained: Characteristics and Composition

Soil types come in many textures, colors, and compositions. Each type of soil varies according to the region or climate of its location. Take a sample of the soil in your field or garden and break it down by color and feel to see which of these 28 soil types matches it best. Each layer depth will have different levels of nutrients and minerals, all of which are very important.

soil types

Some of these soil types are very similar, but all have their unique characteristics and physical properties. As soil formation happens over time, that is what forms the layers and distributes certain minerals, such as nitrogen and phosphorus, throughout the soil. Learning the soil type will determine the best use of the soil. You will be able to determine whether it is ideal for your desired plants, and if it needs any adjustments.

Soil Types by Texture

Soil texture describes the makeup of a type of soil. Certain soil textures, such as loam, clay, and sand, are definitive terms for the percentage of sand, silt, and clay within a soil layer.

Depending on the texture of a plot of soil, it could determine how well the land will grow crops and other plants. An apple orchard may not need the same type of soil of another set of crops, such as soybeans or corn.

The soil texture type is also a good indicator as to which types of plants are the best to put in a garden.

A soil’s texture comes from how much sand, silt, and clay is in it.

The percentage of sand in a soil texture contains mineral soil particles with diameters ranging from 2 to 0.02 mm.

The part of the soil that is silt also has mineral soil particles, but with a diameter range of 0.02 to 0.002 mm. Silt is finer than sand.

The percentage of clay has soil particles that are less than 0.002 mm in diameter, which is smaller than both Sand and Silt.

Unequal portions of sand, silt, and clay make up a soil’s texture and determine its classification.

What Is Loam Soil?

Loam soil has close to equal parts of each type of soil particles, with less clay. Typically, loam soil has 7-27% clay, 28-50% silt, and <52% sand. Often, loam soil has equal parts of sand and silt.

What Is Clay Soil Type?

Clay soil has at least 40% of its soil made up of clay, less than 45% sand, and less than 40% silt.

What Is Clay Loamy Soil Types?

A clay loam soil texture has 27-40% clay and 20-45% sand with little to no silt.

What Is Silty Clay Soil Types?

Silty clay soil has equal parts of clay and silt. There should be at least 40% of each or more, but no less.

What Is Sandy Loam Soil?

Sandy loam soil has mostly sand. A sandy loam usually has about 30% of coarse to medium sand with less than 30% fine to very fine sand.

What is Loamy Sand Soil Types?

(Not the same as Sandy Loam) Loamy sand soil has 25% or more of very coarse to medium coarse sand and less than 50% fine to very fine sand.

What Is Sand Soil?

Sand soil has 25% or more of very coarse to medium sand and less than 50% of fine sand. Typically, sand soil does not contain silt or clay.

Soil Types by Composition

soil characteristics & composition: loam, clay, silt, sand, Gelisols, Histosols, desert, tundra, permafrost and acidic or alkaline.

The Natural Resources Conservation Service (NRCS) of the United States Department of Agriculture (USDA) uses a Soil Taxonomy classification system for interpreting soil surveys. This classification system shows the characteristics of specific soil compositions and where they originate.

Use your knowledge of these soil types to determine the type of soil in your region and what kind of nutrients it contains. Specific fertilizers or soil additives may accommodate any nutrient deficiencies.

View the PDF provided by the USDA – Soil Taxonomy

Gelisols

Gelisols are perennially frozen. They are often described as the “permafrost” and are only in the Antarctic regions or extremely high elevations.

Histosols

Histosol soil forms under swamps and bogs. They contain high levels of organic content due to the preservation of dead plant and animal tissues. You can find histosols in Canada, Russia, and Scandinavia, primarily.

Spodosols

The spodosol soil type has high acidity and is suitable for orchards, usually. Spodosol soils are in the tundras of northern North America, Asia, subtropical North American states such as Florida, and in the lowland regions of tropical South America. Spodosols have a sandy underlayer.

Andisols

Andisol has a volcanic-ash parent material but exists in all climatic regions. With the right conditions, andisols are erosion-resistant and high in mineral nutrients, which is ideal for plants. However, when reacting with phosphorus, it is not ideal for plants because nutrients are cut off in the reaction.

Oxisols

Oxisols are found in the humid tropical zones in South America and Africa. It takes vigilant planning and adjustments to make this type of soil ready for farming. To plant crops, you will need to add lime and fertilizers.

Vertisols

Vertisol soil is rich in clay and cracks with reduced precipitation. This type of soil thrives in standing surface water, which makes it suitable for the cultivation of plants, such as rice. You will find vertisols in tropical zones in Australia, India, Africa, and the western side of the United States.

Vertisol Example

Aridisols

Desert like soil are the aridisol soil type. Plants may only grow in an aridisol if they are drought tolerant. Aridisols usually have a low-humus surface layer on top of a clay horizon.

Ultisols

Ultisol soil has a red color to it due to an excess of metal oxides and is rich in clay. Ultisols support the vegetation of forests and are usually in southeastern United States, China, South America, and Africa. The uppermost layer of a ultisol is humus-rich. An example of a Ultisol would be Red Soil.

Mollisols

The mollisol soil type has a buildup of humus on the surface. This type of soil forms under native grass vegetation.

Mollisols cover about 6% of nonpolar continental land area on Earth. Typically, mollisol soils contain plenty of calcium, magnesium, potassium, and sodium. Plants such as apple trees, broccoli, cabbage, carrots, cauliflower, and various fruits may grow best in a mollisol because of the nutrient content.

Alfisols

Alfisols contain enough water for three consecutive months of the growing season. Using an Alfisol to plant will reduce the need for soil replenishment. Alfisols are in the cool regions of the world, such as the north-central section of the United States and north-central Europe.

Inceptisols

Inceptisols make up a large percentage of land on Earth at 22%, which includes river delta, upland forests, and tundra environments. Inceptisols are suitable for growing crops and have a reasonable/manageable level of drainage.

Entisols

Entisols are very weather-resistant and can withstand extreme wetness or dryness. You may find entisols soils in wetlands, major desert and dune regions, and river delta. They are rich in nutrients and will provide a suitable amount of water to plants.

Soil Types by Commonly Used Terms

soil types

These soil types may look more familiar to you as they are the common terms people use.

These soil types are particular to climate, and each has specific nutrients and minerals. To find out more details regarding the compositional makeup of these soils and where to find them – click here.

Desert Soil – low nitrogen with high calcium carbonate and phosphate. Read more about desert soil.

Arctic Soil – low in most nutrients; high carbon content

Tundra Soil –has minimal amounts of nitrogen and phosphorus; the soil pH of tundra is very acidic

Permafrost – (similar to arctic soil) high levels of carbon; other nutrients vary depending on what was in the soil at the time of freezing

Taiga Soil – high soil fertility, yet has few nutrients

Red Soil – high in iron and potash; low in other nutrients such as nitrogen, humus, phosphoric acid, and magnesium.

Brown Soil – poor fertility and low in nutrients

Black Soil – high levels of calcium, potassium, and magnesium; low nitrogen

Rain forest Soil – low nutrient content, but can be fertile

Best Soil Types for Gardening

Characteristics & composition: loam, clay, silt, sand, Gelisols, Histosols, desert, tundra, permafrost and acidic or alkaline.

The soil in a garden should provide everything the plants need to survive. There should be an adequate level of moisture/water content in the soil, plus the basic minerals and nutrients that plants need to grow. Plants’ roots will absorb the nutrients and use them to grow tall, conduct photosynthesis successfully, and produce edible foods like fruits and vegetables for consumers.

Desert soil and brown soil, for example, would not be ideal for gardening because of the lack of nutrients in each type.

Loam soils, sandy loam soils, and black soil are typically best for growing plants like herbs and vegetables. Most of the soils you see at your local plant nursery have a loam soil because of this exact reason and are the best soil types for gardening.

Click here to learn three methods to determine soil ph in your garden.

Books About Soil

Characteristics & composition: loam, clay, silt, sand, Gelisols, Histosols, desert, tundra, permafrost and acidic or alkaline.

Books are a great resource for learning more about your soil and its characteristics. Professional gardeners compile their knowledge in easy-to-read guides just for you, so you might as well use them. With more knowledge of soil characteristics, you should have more luck with gardening in the future.

Try out these books!

The Ultimate Guide to Soil (Permaculture Gardener Book 3)

By Anna Hess

Click here for prices

Elements of the Nature and Properties of Soils (3rd Edition)

By Nyle C. Brady and Ray R. Weil

Click here for prices

Building Soil: A Down-to-Earth Approach

By Elizabeth Murphy

Click here for prices

Soil Health, Soil Biology, Soilborne Diseases, and Sustainable Agriculture A Guide

By Graham R. Stirling, Helen Hayden, Tony Pattison, and Marcelle Stirling

Click here for prices

Frequently Asked Questions

soil types

These are the frequently asked questions that you may still have after reading through this information. Every soil is different, so it is best to do as much research you can on your specific soil before trying to adjust any aspects like the pH, moisture, or temperature of your garden. A false understanding of soil could lead to the death of your plants.

How many soil types are there?

Most soil experts would say that there are three primary types of soil, which are clay, sand, and loam. And since these do make up all the different kinds of soil, you could narrow it down to those three. However, as you can see from all the different types of soil in this article, there are many.

Best soil types for construction?

Soils with mostly sand and clay are best for building foundations in construction. Loam soil is a good example of this since it has equal parts of sand and clay and very little silt.

What is soil made of?

All soil formations are different. However, most soils have at least the three main nutrients that plants need – nitrogen, phosphorus, and potassium. The dead, decomposed tissues from plants and animals also break down and combine with the components of the soil (this is called the organic matter), which contributes to the nitrogen content.

How to determine soil texture?

When determining the texture and type of soil, you will need to extract a soil profile from the ground, which is a long piece of the soil that contains all depths.

Use your garden tools to get a soil profile. Then, use online guides such as the Guide to Texture by Feel, which are provided by the United States Department of Agriculture to help you determine the texture and other elements of the soil.

Conclusion

The composition of soil can determine whether or not your plants will grow. Plants need nutrients, and the soil can provide that as long as you have the right type. These soil types show the major differences between soils and how each functions best in a particular type of climate.

Common soils, such as black soil and loam soil, may seem familiar and are relatively easy to find. However, when it comes to rain forest soil and other specific soil types, you may need informational guides such as this to help you learn where to find them.

Leave a Comment