How to Test Topsoil

Overview

Soil in your garden is divided into what Utah University Cooperative Extension calls "horizons." The surface layer of the horizons is darker, richer and full of organic matter. This 2- to 10-inch layer of soil is called top soil, and is where your plants do the majority of their growing. Chemical and physical properties determine the quality of a topsoil, including texture, pH and drainage. A soil that tests poorly in any of these areas is not worth purchasing and putting into your garden.

Step 1

Visually inspect the soil for color. The best topsoil, according to Oregon State University, is that which looks dark, is crumbly and smells sweet. Touch the soil and squeeze it in your hand to see if it crumbles.

Step 2

Add water to the soil to determine its composition. Top soil that sticks together has too much of a clay composition while if it it wet and gritty, it contains too much sand.

Step 3

Purchase a pH kit from a local garden center or online and test the pH of the soil. According to Utah State University, soil that has a reading of above 7.0 is alkaline, below 7.0 acidic, and 7.0 neutral. Topsoil reading somewhere around the 7.0 range is of good quality, and is adaptable to most plants.

Step 4

Place a small amount of topsoil in a bowl and add water until it is thin. Preserve a small amount of this water and place it into your pH device's container. Dip the testing strip into the water, or add the chemical included with the pH kit into the water to test the pH. The pH strip, or the water, will change color. This color is checked against a chart and will represent the soil pH.

Things You'll Need

  • Water
  • Shovel or hand trowel
  • pH testing kit

References

  • Oregon State University Extension Service: Test Topsoil Before You Buy It
  • Utah State University Cooperative Extension: Topsoil Quality Guidelines for Landscaping
  • NASA: About Soil pH
Keywords: test top soil, top soil pH, top soil quality

About this Author

Cleveland Van Cecil is a freelancer writer specializing in technology. He has been a freelance writer for three years and has published extensively on eHow.com, writing articles on subjects as diverse as boat motors and hydroponic gardening. Van Cecil has a Bachelor of Arts in liberal arts from Baldwin-Wallace College.