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Johnson County

Research-based Information You Can Trust — Localized for your needs

Johnson County
11811 S. Sunset Drive
Suite 1500
Olathe, KS 66061

Office Hours:

Monday - Friday,
8:30 a.m. - 5 p.m.

(913) 715-7000
(913) 715-7005 fax

Map to our office

K-State Research and Extension is committed to making its services, activities and programs accessible to all participants. Reasonable accommodations for persons with disabilities may be requested by contacting Johnson County Extension at (913)715-7000. Notify staff of accommodation needs as early as possible.

Kansas State University Agricultural Experiment Station and Cooperative Extension Service

K-State Research and Extension is an equal opportunity provider and employer.

Soil Testing

What is a soil test?
A soil test measures soil pH and available nutrients in the soil. It cannot identify insects, diseases, or chemical pollutants, and cannot answer questions about soil composition, drainage or compaction.

Why test the soil?
Testing the soil gives you accurate information about the type and amount of fertilizer or amendment to apply in order to maintain good plant health. This helps protect the environment, and can lead to success in your lawn and garden. 

Can I get the free soil test?

Johnson County residents receive a free soil test each calendar year.

  • Bring two cups of soil in a plastic zipper-storage bag to our office.
  • Write your name and phone number on the outside of the bag.
  • Print off and fill out a soil test request form to accompany your sample. 

Soil Test Request Forms:
Select the corresponding form below for the type of plantings in the soil you want tested. Print the form and answer all the questions as completely as possible.

To give you the best recommendations, we need to know about fertilization practices, soil amendments, mowing (turf) and any special problems in the test area.

On the forms for "Test Requested," package #1 is the most common test and the free test for Jo Co residents. Additional samples or testing have a fee associated with it. See the right hand column for more information. 

How to take a good soil sample:

Scooping soil from a trug into a plastic bag
Test results will only be as reliable as the sample collected, so proper methods are important. Follow these steps:

Using a clean shovel or soil probe, dig down to a depth of:

  • 3 inches for lawns,
  • 6 inches for vegetables, flowers and small fruits,
  • 10 to 12 inches for trees and shrubs.

Take at least 4 - 5 samples from the area to be tested to equal two cups. Mix samples together in a clean, plastic container. Remove all plant material or debris.

  • Create separate samples for each area you want to have tested.
  • Avoid sampling overly wet soil, and soil that has been recently fertilized.
  • Samples should be dry. Do not use heat to dry your sample.

What if I am testing agriculture fields? 

Bring or mail to our office:

  1. Completed form,
  2. Bagged soil, and
  3. Additional payment, if needed. (Cash, check or credit card is accepted. Make checks payable to: Johnson County Extension Council.)

To: Johnson County K-State Research and Extension,
11811 S. Sunset Dr. Suite 1500,
Olathe, KS 66061-7507

Office hours: 8:30 a.m. to 5:00 p.m., Monday - Friday 

  • Important Note for Johnson County Residents Wanting a Free Soil Test: Please do NOT send your sample directly to the K-State Soil Lab in Manhattan, Kansas. If you do, you will be charged by the university.

  • The offer for one free soil test is only available for samples that are processed through our office.

Map to our office

Lab results
Samples are sent to the Soil Testing Laboratory at Kansas State University. The results will be analyzed by our Horticulture agents here in Johnson County, and a report will be mailed to you.

The average time required to complete the analysis for lawn or garden samples is 2 to 3 weeks. During the spring or fall lawn renewal season, this turn-around time may take longer due to the increase in samples volume. Please take this into consideration in your planning.

Other Resources

Available Tests and Fee Schedule

Many different analyses are conducted at the KSU Soil Testing Lab.

The most common tests for Kansas soils are for pH, phosphorus (P), potassium (K), nitrate (NO3), and organic matter. Below are the base packages recommended for most situations.

Package #1 - pH, P and K. This information is sufficient for most home lawns, vegetable and flower gardens. Recommend for gardener using traditional chemical forms of fertilization. Soil testing fee-$12.00.

  • Note: Johnson County residents get one free basic soil test per household address. Sample MUST be brought or sent to our office in order for there to be no charge. If you send your sample directly to the K-State Soil Lab you will be charged by K-State.

Gardeners Package-pH,P, K, Organic Matter and Nitrate levels. This package is recommended for organic gardeners or those who use compost, manure, or other organically and nitrogen rich products in their fertility program. Soil testing fee-$20.00.

Package #2 -  pH, P, K, Nitrate and Zinc. This package is rarely needed for home gardeners unless they grow crops that require zinc such as fruit and nut crops. Soil testing fee-$20.00.

Package #3-pH, P, K, Organic Matter, Calcium, Magnesium, Sodium, and CEC. This package is recommended only for specialty crop growers. (Not recommended for home gardeners.) Soil testing fee-$20.00.

Additional testing is available through the K-State Soil Lab. Please ask about special needs for your soil.

Heavy Metals Testing

Local soil for gardening may have the potential to be contaminated with metals from  lead based paint, manufacturing or industry. Gardening in these soils could be potentially harmful. The soil lab can test for the following heavy metals: Lead, Arsenic, Cadmium and Chromium. Complete Heavy Metals Panel Soil testing fee-$30.00. First Metal $15.00. Additional trace elements $3.00 each.