Soil Nutrient Testing Program
All soil samples must be THREE POUNDS.
King Conservation District provides basic soil nutrient tests for all residents and municipalities in our service area (see sidebar). KCD’s soil nutrient testing program covers commercial farms, pastures, parks, home yards and community gardens.
Soil samples can be mailed to KCD’s office Monday through Thursday or put in our drop box outside KCD’s office door located inside the building at 800 SW 39th St, Suite 150, Renton, WA 98057 during the hours of 8:30am to 5:00pm, Monday through Friday.
Download KCD’s Soil Testing Fact Sheet PDF
KCD Soil Sample Submittal Form
Each resident in our service area is eligible for a total of five free basic soil nutrient tests for properties they either own or rent. Additional soil tests can be ordered for $25 each.
We will send your soil samples to A and L Western Laboratories in Portland, OR to test for Nitrogen, Phosphate, Potassium, Magnesium, Calcium, Sodium, Sulfur, Organic Matter, pH, and Cation Exchange Capacity. The laboratory will analyze your soils and provide recommendations specific to your plant needs.
KCD pays only for basic nutrient tests. Additional tests for heavy metals or other soil properties are charged separately. See the Analytical Services section of the A and L Laboratories website for prices.
It’s easy to collect soil samples. See our Soil Sampling Instructions and Submittal Form for details. Read the instructions carefully and fill out the submittal form so we get complete information about your soil sample. Be sure that:
- Each sample has at least THREE POUNDS of material
- The forms are properly filled out
- The sample bags are filled out on the outside of the bag
It’s important that soil samples are fresh, so please don’t mail them on Friday or Saturday so they don’t sit at the Post Office for a few days. Soil nutrient test results are generally available within two to three weeks from when we send them to the lab.
KCD recommends testing soils regularly. Whether you are growing forage for livestock, gardening, maintaining an orchard or managing a woodlot for wood production, proper soil sampling will allow you to:
- Apply the correct amount of fertilizer for the plants you are growing.
- Prevent surface and ground water from being contaminated by excess fertilizers.
- Ensure that soil nutrients and other conditions (such as soil acidity) affecting plant growth are present in the right amounts.
Results of proper soil nutrient management can include:
- Increased plant growth, yields and quality.
- Less purchased livestock feed and fertilizer.
- Better utilization of manure on your pastures, lawns and gardens.
For more information contact soiltests@kingcd.org.
Additional Helpful Information
How to Have a Dynamite Lawn by Ciscoe Morris (PDF)
Soil Testing Information from Grow Organic/Peaceful Valley Farm Supply
Understanding Your Soil Test Report by Peaceful Valley Farm Supply (PDF)
Technical Advice Fact Sheet 12 – Soil Testing from A Greener World (PDF)
Interpreting Your Soil Sample Report from Penn State University Extension (PDF)
Soil Amendments and Fertilizers from University of Maryland Extension
Soil Amendments and Fertilizers from Grow Smart, Grow Safe®
Soil Testing: A Guide for Farms with Diverse Vegetable Crops from Washington State University Extension