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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:

Make an appointment, before coming into the office.

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

(913) 715-7000
(913) 715-7005 fax
jo@listserv.ksu.edu

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

COVID-19 UPDATE: 

We are accepting soil samples at the Johnson County Extension Office. Here are a few things you will want to know:

  • Please bring two cups of soil in a resealable, quart-size plastic bag.
  • 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.
  • Once you arrive at the office, leave your sample with your complete form in the box labeled "Soil," outside the Extension door in the lobby. Staff will collect the samples throughout the day.
  • Johnson County residents receive a free soil test each calendar year.
  • If you would like to purchase an additional sample, you are welcomed to do so. If paying with cash, at this time we will only accept exact payment. Checks can be made out to: Johnson County Extension. Credit/debit is still accepted at the office.
  • You can also mail in your sample. 

Soil Test Request Forms:
Select the correct 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.

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 save you money and time.

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. Mix samples together in a clean, plastic container. Remove all plant material or debris.

Bring two cups of the mixed soil to the Johnson County Extension Service in a resealable, quart-size plastic bag.

  • 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.

Bring or mail:

  1. Completed form,
  2. Bagged soil, and
  3. Check or cash for the desired test  (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: Do NOT send your sample directly to the K-State Soil Lab. If you do you will be charged by the university.

  • The offer for one free soil test will only be honored 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. Their 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.

Package #1 - $12  (pH, P, K) This is the basic fertility test, sufficient for most homeowner lawns and gardens.

Package #2 - $20  (pH, P, K, NO3, organic matter). For soils that might have too much nitrogen or organic matter due to continuous heavy applications of fertilizer, compost, or manure.

Other Individual Tests: (rarely needed for the homeowner)

Individual Trace Elements: $3 per element

  • Calcium (Ca),

  • Magnesium (Mg),

  • Sodium (Na),

  • Iron (Fe),

  • Zinc (Zn),

  • Copper (Cu),

  • Manganese (Mn),

  • Sulfate (SO4),

  • Chloride (Cl),

  • Aluminum (Al)

Nitrates: $5

Ammonium: $5

Heavy Metals Arsenic, Cadmium, Chromium, Lead:

  • First metal $15.

  • Additional metals $3 each.

  • Complete panel: $20

Organic Matter: $5

Cation Exchange Capacity: $15