Soil test laboratories offer a variety of soil tests. The tests are carried out by experts with first-class equipment, so the results are more accurate and informative than those from tests you carry out yourself. In addition, the lab technician usually gives recommendations for ways to improve your soil, such as precise amounts of nutrients or soil additives needed.
Laboratories generally offer batteries of different tests. Tests for soil pH and soil salts are common, as are tests for organic matter content, and amounts of some of the common plant nutrients. In addition, labs can measure the physical characteristics of your soil, test for many micronutrients and secondary nutrients, and look for any toxins you might suspect are in the soil, such as herbicides, lead, or cadmium.
University agricultural extension services in many states test soil samples for a nominal fee. In addition, some private soil-analysis laboratories offer testing for individuals.
You can locate a soil test lab in several ways. Here are some ideas:
Call your local cooperative extension agent for a reference. In many states, extension agents act as soil test agents. In the telephone book, look for “Cooperative Extension” under the county listings.
Ask at your local garden center. They can probably recommend a soil test laboratory.
Look in the yellow pages of your telephone book. Soil testing laboratories are usually listed under “Laboratories, Testing”.