Drainage of Different Kinds of Soils

Overview

Water and oxygen are used by plants to produce carbohydrates---food that makes growth possible. In order for plants to thrive, different plants require different kinds of soil to provide both substances to their root systems.

Soil that holds water cuts off a plant's oxygen supply. image by Image by Flickr.com, courtesy of John Lustig

Soil is formed when rocks break down. image by Image by Flickr.com, courtesy of Patrick Fitzgerald

Soil Layers

Soil is ruined rock from the earth's interior. Geologic processes break this rock into smaller bits until it forms layers of gravelly subsoil and fine-textured topsoil.

Topsoil must combine soil types to drain water successfully. image by Image by Flickr.com, courtesy of OakleyOriginals

Topsoil

Topsoil needs a good layer of subsoil to drain well. Its dark color is because of its content of organic matter from decaying plants, roots and animals.

Sand supports mainly deep-rooted plants. image by Image by Flickr.com, courtesy of Sergio Tudela Romero

Sand

Sand is the largest particle of topsoil. Sandy soil is highly permeable; it absorbs water readily. It is the most porous soil with a lot of room for oxygen between particles.

Silt predominates in rivers and waterways. image by Image by Flickr.com, courtesy of Kevin Dooley

Silt

Silt is the next smallest particle in topsoil. It is less porous and also less permeable; it will hold water and organic matter better than sand. Marshes have soil with a high percentage of silt.

Clay holds water, making it a good building material. image by Image by Flickr.com, courtesy of woodley wonderworks

Clay

Clay is the smallest element in topsoil. Clay leaves little room for oxygen or water to drain through. Friable soils (soils that drain well) have less than 20 percent clay.

Organics plus a balanced soil equals loam. image by Image by Flickr.com, courtesy of Joe

Loam

Adding organic matter to soil makes it loamy. Loam and sand improve friability in clay-heavy soils. Sandy or silty loam should drain about 2 inches of water in an hour for many common garden plants to thrive.

References

  • Soil Physical Properties
  • Improving Soil Drainage

Who Can Help

  • Solutions to Soil Problems; Drainage
Keywords: soil, different kinds, drainage, water, root systems

About this Author

Laura Reynolds began writing professionally in 1974. She has worked as author and editor in nonfiction, professional journals and newspapers. Reynolds has also served in numerous appointed and elected local offices. She holds a Bachelor of Science in education from Northern Illinois University.