A soil test is a test which is used to gather information about the composition of the soil in a particular area. In a classic soil test, multiple samples are taken from the region of interest and tested before being averaged, ensuring that a random area of contaminated soil does not skew the sample. There are a number of reasons to conduct soil testing, ranging from a desire to grow a healthier garden to curiosity about potential contaminants in the soil.
A typical soil test is done by taking samples and sending them to a lab for investigation. In some cases, a government agency may pay for the soil test. For example, if tenants suspect that a substance which is bad for them is in the soil, the public health department may take samples and pay for the testing. In other instances, the cost of the soil testing is the responsibility of the person ordering the test.
When a lab performs a soil test, it sends back detailed results, often with a soil test guide so that people understand what the results mean. Many gardening organizations also publish soil reviewing tips, so that gardeners know how to address specific soil test results.
Gardeners use soil testing to learn about the pH balance and mineral composition of their soil. This can be used to determine which soil amendments should be added to keep the garden happy and healthy. For example, acidic soil would need to be modified with a base, or the gardener would need to plant things which can tolerate high acid levels. Improving soil quality is often an ongoing task for gardeners, and the soil may be tested on a regular basis to see whether or not soil amendments are being retained.
Before ground is broken for a new construction project, soil testing is sometimes required, along with an environmental impact report. The soil testing can sometimes turn up important information which may have an impact on the construction. For example, if the testing reveals the presence of a contaminant in the soil, the contaminant may need to be cleaned up before construction can commence. People who are buying land with plans to develop it may want to consider getting a soil test done before signing a purchase contract.
Environmental agencies also routinely use soil testing in their works. Soil tests are performed to monitor problem areas for pollution and released contaminants, and to keep an eye on environmental remediation programs. If land does require environmental cleanup, a soil test must be performed at the end of the cleanup to confirm that the soil has been properly handled and the land is safe to use.