Understanding MSU soil test report basics – Part 1 of 2

Get the most out of your MSU soil test report with these tips on collecting a good soil sample for testing.

Michigan State University Extension promotes regular soil testing for all commercial crop production. Many farmers soil test regularly or occasionally. MSU’s Soil and Plant Nutrient Laboratory is an excellent place to have soil samples analyzed. There are other good options for soil testing, including several public and private laboratories.

After 26 years of reviewing MSU soil test reports and making fertilizer recommendations for farmers, gardeners and others from across the Upper Peninsula, I have the following pointers regarding the MSU soil test report.

Want a useful report? Collect a good sample!

  • Collect a good, representative sample. If you don’t know how, review the process in “Sampling Soils for Fertilizer and Lime Recommendations,” MSU Extension publication E0498.
  • Make sure you sample as deeply as you intend to till the ground. If you are not tilling the ground, such as in pasture, hay, lawns or other perennial crop situations, then sample 3 inches deep. In long-term, no-till systems, a 2-inch deep sample should be collected to test pH, and a separate sample 6-7 inches deep collected for other nutrient information.
  • Be sure to include the depth of tillage on the MSU Soil Test Information Sheet. The depth you indicate has a direct relationship to the amount of lime recommended, if any is needed. For example, twice as much lime will be recommended for 8-inch tillage compared to 4-inch tillage. If you don’t specify a tillage depth, the laboratory will automatically enter a 9-inch depth.
  • Select the crop to be grown carefully from the list on the soil test information sheet. If an exact fit isn’t listed, pick the closest thing and include a note on the information sheet. This will help your local Extension educator or farm supply dealer understand what is planned. If you list multiple crops as “1st year crop” and “2nd year crop,” but you intend to plant them together, include a note on the information sheet to make this clear. A “2nd year crop” will take into consideration any nitrogen credits estimated from the “1st year crop” listed, if it is a legume.
  • Include a realistic yield goal for the crop or crops you plan to grow. If records are available, this could be the average yield of five previous normal years. Feel free to be optimistic, but understand the higher the yield goal, the more nutrients will be recommended. If you don’t indicate your desired yield, the laboratory will include a “default” yield which could be too high, resulting in an excessive nutrient recommendation, or too low, resulting in an inadequate nutrient recommendation. This is a common problem on soil test reports, especially those from farmers unfamiliar with the system.
  • Include your email on the information sheet if you regularly check it for messages. The laboratory will be able to email you and your local Extension educator an electronic copy of your report as soon as it is completed. This will be quicker than U.S. mail. If you have questions regarding the report or need specific fertilizer recommendations, please contact your local Extension educator.

Part 2 of this article will include tips for interpreting your MSU soil test.

Questions? Contact your local MSU Extension field crop, vegetable or fruit educator about commercial soil test reports. For home gardening and landscape soil test reports, contact the MSU Extension toll-free hotline at 888-678-3464.

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