Soil Sampling: When, How, and Why

Rob Last Area Horticulture Agent. 

When?

Whether you are a homeowner or commercial farmer, winter is a great time to take soil samples. When the lab reports the results, winter allows applications such as lime to adjust soil pH in plenty of time for the spring growing season.

How?

Step one: Decide on the number of samples to be submitted

Sampling should be based on plants to be grown. For homeowners, take one sample of turf, one of the flower beds, shrub areas, and vegetable garden or fruit trees. Separate samples will provide the most accurate recommendations.

For larger areas such as commercial farms, split the field into ten-acre blocks.

Step two: Collect the samples

Collect a minimum of ten subsamples from the selected area.

Collect the subsamples in a bucket and combine them before putting the sample into a soil analysis bag.

Samples should be from a depth of six to eight inches.

A soil probe or a bucket and trowel are great tools for collecting the subsamples.

Fill the sample bag to the line, approximately one cup of soil.

Ensure the bag has your name, a sample identification, email address, City and State where you collected the sample, the crops or plants to be grown, and the county where the soil was collected.

For more information see this video.  

Step three: Fill out the paperwork

Some key points, make sure the sample identification on the bag matches the sample identifier on the submission paperwork.

Make sure you have written in the crop and found the crop and soil codes.

Then either mail the samples directly or drop them in at your local Clemson Cooperative Extension Service Office.

For more information, please use the following links:

Soil Form Instructions 

Soil Testing Crop Codes

Soil Testing Soil Codes

Why take Soil Samples?

Assessing the soil’s chemical properties and nutrient levels helps us as growers and homeowners provide optimum nutrient and soil conditions to grow our plants without over or under applying nutrients successfully.

Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, gender religion, national origin, disability, political beliefs sexual orientation, gender identity, marital or family status and is an equal opportunity employer.