Fertilizing and Soil Testing
Maintaining a healthy soil is key to growing healthy plants. Keys to a healthy soil include: incorporating organic matter (such as compost) regularly, improving aeration and decreasing compaction, and maintaining ideal soil pH and nutrient levels. Maintaining soil pH and nutrient levels requires a regular soil nutrient test. We recommend that you test your soil every 3-5 years.
Programs We Offer
Most of our classes and seminars include information on appropriate soil care for the plants being grown.
We offer soil testing services through the K-State Soil Testing Laboratory. You can bring your soil samples to our main reception desk during business hours to complete the paperwork, pay the fee, and have your sample submitted to the lab. Your results will typically be available in 2-3 weeks and will include written recommendations of what you need to do to improve your soil pH and nutrient levels.
How do I submit a soil sample for testing?
K-State requires about 2 cups of soil for a soil test. It is important to collect your soil correctly to get good results.
- Identify the area that you want to test. Each unique garden or area of your yard should be tested separately for best results. Problem areas should be tested separately.
- Collect 8-12 scoops of soil randomly throughout the area that you want to test. These scoops of soil should each include the soil from the surface to 6" deep.
- Mix all of the soil together in a bucket and then put 2 cups into a plastic bag or other container.
- Label the bag or container for each part of your yard or garden clearly so that you can match up the recommendations if you are having multiple tests done.
- If the soil is wet, allow it to air dry overnight or for a day or two.
- Bring your soil to the main reception desk at the Extension office to complete your paperwork and pay the testing fee.
For other soil testing FAQs, please visit our Soil Testing page.
Can I apply gypsum to help with my tight clay soil?
Gypsum does not help with compaction or otherwise "loosening up" a heavy clay soil. Large amounts of gypsum and high quality irrigation water will help improve the soil structure in a clay soil that has been contaminated with sodium, but that is not the case for the vast majority of our clay soils. The best way to improve a heavy clay soil is by regularly applying or incorporating organic matter and practicing core aeration in lawn areas.
Can I add sand to my clay soil to help improve the texture?
No! Adding sand to a clay soil can be very detrimental. It will usually result in a soil that is even harder and more like concrete than a looser, sandy soil. The best way to improve a clay soil is by adding organic matter.
What can I do to help my soil drain better?
The best ways to improve soil and landscape drainage are:
- Incorporate organic matter
- Use berms and raised beds
- Install swales or drains to help water move away from your yard
When should I fertilize my .....?
Different plants should be fertilized at different times of the year and at different rates. Here are several publications that will help you determine correct fertilization times and rates.