How to collect soil; there will be a test
If you have never done soil sampling, or if it has been several years, now is the perfect time to take a sample. Soil testing provides a starting place for soil improvement for the home garden, lawn or landscape.
There are many benefits of soil testing. One advantage is an accurate measure of the nutrients already in the soil and an identification of nutrients that are lacking. This can help reduce fertilizer applications and provide a proper balance of plant nutrients thus reducing chances of excess nutrients getting into our rivers and streams. Soil testing also allows adjustment of soil pH to an optimum level for plant growth.
It is always best to have the soil tested rather than guess which fertilizers to use and how much to apply. To make sure the test is accurate, sample the soil before fertilizer has been applied and follow proper collection procedures.
The Oklahoma State University Soil Testing
Lab will check for basic pH levels, as well as Nitrogen (N), Phosphorus (P) and Potassium (K). Once your test is completed, our office will analyze it for you and make recommendations.
When you go to buy a fertilizer, you will find that it has three numbers, such as 46-0-0, or 10-20-10, on the package. These stand for the N-P-K (nitrogen, phosphorus and potassium) levels. N is always the first number, P the second and K is third.
A soil test can help you choose the right fertilizer, since you will know if you need a fertilizer with just nitrogen or one with complete nutrients. Since you usually pay a higher price for fertilizers with all three nutrients, you can see why buying a fertilizer with just nitrogen can save you money. Also, these days you can find organic fertilizers on the shelf next to synthetic products, so you have many choices.
On the average, soil tests in Oklahoma County are either adequate or high when it comes to phosphorus and potassium. Nitrogen is usually a different story.
Plants will use a lot of nitrogen when they are actively growing since it is central to the chloroplast molecule which drives photosynthesis. Some fast-growing plants such as Bermuda grass may need a nitrogen application monthly.
A soil test also checks the pH level of your soil. The ideal pH level for most plants is 6.5 to 6.8. If your pH is too acidic or alkaline, some of the nutrients your plants need to grow may be tied up and not available, and a soil analysis can help you correct this.
To collect a sample, collect soil from 12-15 different places at a depth of 6 inches from the lawn, garden or beds you wish to test. Mix these samples together in a clean bucket or pail and collect 2 cups from the mixture to bring to the Extension Center, 2500 NE 63, weekdays from 8 a.m. to 4:15 pm. We will send the sample to the Soil Testing Laboratory at OSU and then analyze the results for you. You will get your results in 2 weeks, and the cost for each sample is $10.
If you take samples from more than one area, be sure to label them. Also, be sure to indicate on the sample what you are growing, since plants have different needs and we can analyze the sample better if we know what you are trying to grow.