A soil test provides information on the basic fertility of soil. It is the starting point for determining how much and which fertilizers to use on a crop. Without a soil test, everyone is guessing at what the soil fertility level really is.
Through a grant from the Douglas County Conservation District, Douglas County Agriculture producers are eligible for up to 10 free soil tests.
How to Collect Soil Samples
Proper collection of a representative soil sample is important for accuracy and analysis of test results.
Follow these steps to obtain a good sample:
- Decide if your field can be treated as one sample or needs to be broken down into separate smaller samples. If you believe the soil type, previous crop and fertilizer treatments are consistent across the field, treat it as one sample. If soil type and topography change across the field, different crops have been planted on different parts of the field, or there are problem spots, break the field down into smaller units to sample.
- Using a soil probe, dig vertically to a depth of 4 inches for established fields such as brome, alfalfa or a no-till field. Fields that are worked up should have samples taken from 6 inches. Avoid sampling in old fence rows, dead furrows, low spots, feeding areas, and other areas that might give unusual results. If information is desired on these unusual areas, obtain a separate sample from the area.
- Take at least 10 – 15 samples from the field and mix the samples together in a clean container to create a representative sample. The more sub samples you take, the more assured you'll be that soil test results are representative of your field. Bring approximately two cups of the mixed soil to the Douglas County Extension Office in a paper bag.
- Samples should be dry. You can let samples air dry, but do not use heat to dry your samples.
Bring or mail the soil sample(s) to:
Douglas County K-State Research and Extension,
2110 Harper St.
Lawrence, KS 66046
Office hours: Monday – Friday, 8:00 a.m. – 5:00 p.m.
We will need the following information:
- Name, complete mailing address, e-mail and phone number
- Sample depth
- Previous crop and its yield
- Intended crop and a yield goal (indicate if this is a new seeding for pastures)
- If pasture, classify as brome, fescue or native/prairie.
The sample will be sent to the Soil Testing Laboratory at Kansas State University for analysis. Their results will be analyzed by our Agriculture agent and a report will be mailed to you. The average time required to complete the analysis is 2 – 3 weeks. During the spring season, this turn-around time may take longer due to the increase in samples volume. Please take this into consideration in your planning.
Soil Test Interpretations & Fertilizer Recommendations