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. Below (under FAQ's) are detailed instructions for collecting a soil sample. Once you have collected your sample, bring it to the main reception desk at the Extension Office (7001 W. 21st St. N.) to complete your paperwork and pay the testing fee. Please use the entrance by the flagpole in front of our building, and ring doorbell for admittance.
We will forward your soil sample to the K-State Soil Testing Laboratory for processing. Results will take 4-6 weeks to be returned to you, and will include personalized written recommendations of what you need to do to improve your soil pH and nutrient levels.
Please use the following Information Sheets when submitting your samples:
- Agriculture Soil Sample Information Sheet
- Vegetable and Fruit Soil Sample Information Sheet
- Lawn and Turf Soil Sample Information Sheet
- Ornamentals Soil Sample Information Sheet
After you have received your results, you may contact one of the local agents if assistance is needed in understanding the results and recommendations.
- Agriculture: Jeff Seiler
- Food Crop Horticulture: Rebecca McMahon
- Ornamental Horticulture and Lawn samples: Matthew McKernan
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 for vegetable or flowerbed samples. For turfgrass areas, collect soil samples from the surface to 3" 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 sample(s) 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.