How to collect a soil sample at your home:
Since only a small portion of the soil is used for testing, it is very important that the sample be representative of an area. For a standard soil test, take several samples from each area of your yard (front yard, shrub bed, garden, etc.),. For large areas, 5-8 cores are needed, but for narrow shrub or flower borders, 2-4 cores will do the job. Mix all of the samples together in a clean pail or bucket to get your representative sample or "average" soil for your yard.
If you are targeting a problem area, you can restrict your sampling to the problem area only.
For complete instructions, view the Purdue Extension Collecting Soil Samples for Testing Publication here. Or watch the How to Collect a Soil Sample- YouTube Video from Noble Research Institute
Since only a small portion of the soil is used for testing, it is very important that the sample be representative of an area. For a standard soil test, take several samples from each area of your yard (front yard, shrub bed, garden, etc.),. For large areas, 5-8 cores are needed, but for narrow shrub or flower borders, 2-4 cores will do the job. Mix all of the samples together in a clean pail or bucket to get your representative sample or "average" soil for your yard.
If you are targeting a problem area, you can restrict your sampling to the problem area only.
- Remove surface debris, such as plant residues, mulch or turf thatch, from the soil before inserting the soil probe, spade, or trowel.
- Sample gardens and shrub and flower beds to a depth of 6-8 inches.
- Sample turf areas to a 3-inch depth.
- Sample tree root zones to 8-12 inches or deeper.
- Sample row crops (in gardens) between the rows to avoid fertilizer bands.
- Sample front and back yard separately if they have been managed differently or contain different types of fill soil.
- Dry samples at room temperature. (Do not use artificial heat.)
- Break up any lumps and remove all stones, debris, grass, etc. When dry, mix well and eliminate clumps.
- Bring ~2 cups of soil to the SWCD in a clean container for testing.
For complete instructions, view the Purdue Extension Collecting Soil Samples for Testing Publication here. Or watch the How to Collect a Soil Sample- YouTube Video from Noble Research Institute
Nutrients & Measurements (pH)
- Optimum pH for gardens: 6.0-7.0; pH for turf: 5.5-6.5
- Phosphorus for garden: 20-40; Much less for turf or anything with permanent roots
- Potassium, magnesium, and Calcium: varies depending on CEC for soil.
- CEC: Cation Exchange Capacity- soils ability to hold positive charged particles like K, Mg, and Ca; good levels are between 7 and 15
Organic Matter (OM)
- OM levels are ideal at 5-8%,
- If OM levels are below 2-3% nutrient and water holding capacity become limited and may not support plant growth;
- High OM (10%+) can cause wild fluctuations in nutrient availability, especially nitrogen
