Getting a Soil Test
To improve your soil, you need to understand what you have in order to apply the right soil amendments. The best way to test your soil is to send a sample to a Cooperative Extension Service (CSREES) (usually located at or affiliated with a state university) or commercial soil laboratory (check out the print or online Yellow Pages under “Laboratories—Testing” for commercial soil-testing labs). The best time to test soil is in the spring, before you add any compost or other amendments, although you can test soil any time.
Test results will indicate your soil’s current pH and nutrient content, and will tell you what to add to achieve the correct pH and nutrient levels. Some labs will also tell you what type of soil you have and how much organic material your soil contains. Lab tests from state universities usually cost around $20, including the return postage. Commercial lab tests can cost more than $100, depending on the amount of information you request. Kits from soil labs provide instructions for collecting soil samples and a mailing container for returning the soil.
Collecting Soil Samples:
- Use a clean, rust-free trowel to take samples from up to 10 areas of your lawn.
- Dig several holes in the lawn 6- to 8-inches deep.
- Take a slice of soil from one side of each hole, save 1- to 2-inches from the middle of the slice, and discard the sides, top, and bottom.
- Mix the samples in a clear container, allow them to dry at room temperature, enclose a small fee, and send it all to the lab.
If your lawn has areas that range over various types of terrain (i.e., near water, rocky ledge, or imported topsoil), you should request a separate sampling kit for each area. Otherwise the lab may recommend doses of fertilizer or soil amendments suitable for one area but not for another.
Test results will tell you what you need to add to your soil. If you have an acceptable lawn, but are looking to improve it, you may spread the recommended materials over the lawn surface. If your lawn requires restoration, you should aerate the turf with a core cultivator after you have applied the amendments to the surface.
Do-It-Yourself Soil Test Kits
The costs for multiple lab tests, even at nominal lab fees, will add up quickly. If you need to make more than four or five tests on your property, you will probably want to buy your own soil test kit. Kits are available at most garden-supply or hardware stores and range from about $7 for a pH tester capable of doing 10 separate tests to about $20 for a kit that also lets you test basic nutrients (nitrogen, phosphorus, and potash). There are also more expensive kits also available; however, no kit is a substitute for professional soil testing. A kit will not tell you how much soil amendment to add to achieve desired pH or nutrient levels.
A kit is a great way to test several areas quickly to give you a general idea of your soil’s deficiencies. Once you have professional soil test results, a kit allows you to monitor the progress of the soil improvements you make.
Test Your Own Soil
- To test your soil, add the appropriate solution from the kit to a measured amount of the soil sample per the manufacturer’s instructions.
- Shake the solution well and allow the particles to settle.
- Match the color of the resulting solution with the color chart provided with the kit to determine pH or nutrient levels. The chart here suggests a pH of slightly more than 5 indicates acidic soil and the need for an application of lime.
Sample Test Report
Lab test reports can be confusing. Do not hesitate to call the source for help. The report will include maintenance recommendations, pH and nutrient readings, and indicates the amount of fertilizer to apply.