Do It Yourself Instructions for Residential Soil Testing
Does your soil present problems for your plants, trees or lawn?
We are happy to pull, dry, ship and interpret your soil test, but if you want to do it yourself, follow these instructions to do it right.
To save money, use tools you have. A soil test starts with a clean cup or bucket and clean small sampling tool, like a garden spade. If you buy a professional soil sampling tool, you spent any savings on the test on your sampling tools.
If sampling for your lawn, pull samples 3 to 6 inches deep. For garden beds sample a little deeper than 6 inches. Take around 12 samples randomly selected walking around your sample area. Mix the samples in your bucket, then lay on a piece of plain paper to dry. Don’t dry with heat like a hair dryer or oven. When it is dry, fill out this soil test form from University of Massachusetts Soil and Plant Nutrient Testing Laboratory. Select the appropriate form for the site you are testing. We recommend the standard soil test, plus organic matter. Then pour one cup into a zip lock bag for shipment to the laboratory. Mark the sample bag clearly with your sample id. The laboratory will send you results once the sample has been processed.
Once you get the results focus on these areas, but the whole test is valuable:
Soil pH Soil pH is important to help the plant use nitrogen. Ideal range for turf grass is 6.5 to 6.9. For each point below 6.9, the available nitrogen for the lawn is cut in half, meaning the value of fertilization is reduced until the pH is corrected to allow the plant to use the available nitrogen. To correct the soil pH, we recommend applications of the appropriate pelletized lime broken into maximum applications of 25 pounds per thousand square feet every six months. Lime can be applied any time of year, but is usually applied in the spring and fall. We recommend retesting every two years, unless a prior corrective liming program is still ongoing. For example if the last soil test called for 150 pounds of lime which we would break into 6 applications taking 3 years to complete the next soil test could be postponed until after that program is completed.
Phosphorous is the next item we look at. Phosphorous is essential to root growth and can be lacking in New England soils. In Massachusetts a soil test is required to apply phosphorous to a lawn. This application can be done between August 15th and September 21st, as the weather permits, when the plant will utilize it.
Organic Matter levels
Organic Matter levels are the amount of materials containing carbon in the soil. New England soil varies widely with former farmland having much high levels of organic matter than other areas. Soil is made up of a combination of sand, silt, clay, air, water and organic matter. Organic matter is the universal soil improver, helping the soil hold moisture and nutrients.
Cation Exchange Capacity (CEC)
The important Cation Exchange Capacity (CEC) is a measure of the soil’s ability to hold and exchange cations such as potassium, calcium and magnesium. The Percent Base Saturation (below the CEC on the report) shows values for potassium (target 2 to 7%), magnesium (target 10 to 15%) and calcium (target 65 to 75%). By adding materials, we can maintain both the CEC and Percent Base Saturation of potassium, magnesium and calcium.