how do i get soils tested?

Asked February 5, 2016, 9:34 AM EST

Pueblo County Colorado horticulture soil and fertility issues

1 Response

Soil testing starts with collecting a soil sample that represents the area that you want to test. If you have a garden or landscape, then collect 5-10 samples from a uniform area to a depth of about 4-6 inches. Combine the samples in a plastic bucket and mix well. Remove enough sample to fill a sandwich sized plastic bag or plastic container. If there are areas that appear different in slope, soil color, plant species, or other characteristics, then sample those locations separately and submit separate samples that represent those sites. For larger agricultural areas, it may be necessary to take 10 -20 samples per acre, if possible. Time constraints, lack of help, or time of the year may influence how many samples you can take to represent a site, however, keep in mind that the larger number of samples taken from a uniform area that can be combined helps to reduce the variations that can occur in the soil. Be sure to label the sample with the location, date or other information that would help you identify the site. Soil sampling is the most important part of soil testing. The quality of the analysis depends on obtaining a representative sample. You will then need to send the sample to a lab or use a soil testing kit to analyze the soil for parameters such as pH, salts, nitrogen, phosphorus, and potassium. If you use a kit, prepare the soil by air drying it and then crushing it with a mortar and pestle or with a hammer. Sieve the sample through screen material such as what is used for screen doors. We use a 2mm screen to sieve samples in the lab. Follow the instructions and analyze the samples several times to ensure that you are getting consistent results. Most analyses in kits generate a color or other indicator for each parameter. For example, the analysis for phosphorus relies on forming a blue color if P is present. The intensity of the blue color is usually compared to a color chart to determine the concentration of P in the soil, which can then be used to determine whether the soil is low, medium, or high in P. If the soil is low in P or other nutrients, then you will need to add nutrients to the soil at the rates suggested in the kit's fertilizer recommendation booklet. If the P is high in the soil, then you will not need to add P fertilizer. If you want to send the sample to a lab to have the testing done, then include paperwork with your sample that include name, address, phone email, etc. and any information pertaining to any possible problems with the soil such as poor drainage or poor plant growth. Also include the tests that you want done.Most labs have routine test packages that will provide the necessary information to evaluate soil quality and provide information about how to manage the site with added fertilizers, organic matter, or salt reduction. There are also laboratory submittal forms that can be filled out and included with the sample to specify the type of testing you want. The cost can range from about $10.00 to over $50.00 depending on the tests requested. The turnaround time can vary from a few days to about 2 weeks. You can send your samples to the Soil, Water, and Plant Testing Lab at Colorado State University. The current cost is $35.00 for the soil routine test and the turnaround time is about 2 weeks or less. The website is www.soiltestinglab.colostate.edu . You can also check Extension Fact Sheet 0.520, Selecting an Analytical Laboratory for labs that may be in your area. I think the closest ones to you are in Colorado Springs.