The soil test is an excellent measure of soil fertility. It is a very inexpensive way of maintaining good plant health and maximum crop productivity. The standard soil test provides the status of phosphorous (P), potassium (K), calcium (Ca), magnesium (Mg), pH, cation exchange capacity, lime requirement index, and base saturation. Additional tests are also available for iron (Fe), zinc (Zn), manganese (Mn), soluble salts, and nitrates.

OSU Extension in Delaware County still offers soil tests at $20.00 per sample. You will need to bring the soil sample(s) to our office. Please read the instructions below on how to take a soil sample and how to prepare your soil sample for testing. Take soil sample to our office at 149 North Sandusky Street, Delaware, OH 43015. Call us at 740-833-2030 for office hours and directions.

You will receive a detailed soil test report, a letter from Dr. Gary Gao that explains what in the report, and an appropriate fact sheet.

It normally takes 2-3 weeks to get a report back from the lab.

Soil samples can be taken in the spring or fall for established sites. For new sites, soil samples can be taken anytime when the soil is workable. Most people conduct their soil tests in the spring. However, fall is a preferred time to take soil tests if one wants to avoid the spring rush and suspects a soil pH problem. Fall soil testing will allow you ample time to apply lime to raise the soil pH. Sulfur should be applied in the spring if the soil pH needs to be lowered.

A soil test every two to three years is usually adequate. Sample more frequently if you desire a closer monitoring of the fertility levels, or if you grow plants that are known to be heavy feeders.

A soil sample is best taken with a soil probe or an auger. Soils should be collected in a clean plastic pail or box. These tools help ensure an equal amount of soil to a definite depth at the sampling site. However, a spade, knife, or trowel can also be used to take thin slices or sections of soil.

1. Remove the top debris, residue, or turf thatch from the soil surface before taking the sample.

2. Sample gardens, trees, shrubs, flower beds, and orchards 6-8 inches deep.

3. For the lawn, lift the sod and sample 3 inches deep.

4. Sample a row crop field or garden between rows to avoid fertilizer bands.

5. Sample when soils are suitable for spading or plowing.

6. Take separate samples from fields that have received different fertility programs.

7. Take separate samples from soils that are distinguishable by color (i.e. light vs. dark), drainage, or other factors.

The test results are only as good as the sample taken. It is extremely important to provide a representative sample to the testing lab so that a reliable test and recommendations can be made for the entire area. This can be accomplished by submitting a composite sample. A good representative composite sample should contain 10-15 cores or slices. Each core or slice should be taken at the same depth and volume at each site. Sample at random in a zigzag pattern over the area and mix the sample together in a clean plastic bucket.

More samples need to be taken if the area was recently limed or fertilized. Separate samples need to be taken from lawns, gardens, flower beds, or shrub borders. Separate samples should be taken from areas with distinctive soil types or plant performances.

1. Break up lumps and air dry the soil at room temperature with no artificial heat.

2. When the soil is dry, mix well and crush soil lumps to the size of wheat grains or smaller.

3. Take at least one cup of the composite sample to our office. We will mail the sample to the lab for you.