From what I’ve read in Facebook groups and heard from folks, soil sampling isn’t something anyone wants to do. But, the results from a well-executed soil sample, can tell you what your soil is lacking and give you some ideas for how to manage to improve the situation. It can also tell you if your management is making a difference as you’ll have measurements that you can compare over time. What could be more thrilling than that?
So, if you’re growing a crop or pasture, you need to know how to take a good soil sample. Here Dr. Eddie Funderburg of the Noble Research Institute, shows you how.
Tools You’ll Need
If you don’t mind the extra work, you can take soil samples using your sharp shooter shove. But it’s much easier if you buy or borrow a soil sampling probe. (Check with your local Natural Resources Conservation Service office, and while you’re there, ask them for recommendations about where to send you sample for analysis.)
Add a bucket for collecting the cores and you’re ready to go.
Multiple Cores at the Right Depth Are Critical
One core can’t tell you how your whole field or pasture is doing. So you’ll take ten to fifteen cores and mix them up in your bucket.
Because nutrients are stratified in soils, with more at the top and fewer at greater depth, your cores should be 6 inches deep. If your core is shallower, it will look like you have more nutrients than you actually do. If you take it deeper than 6 inches it will look like you have fewer nutrients. Marking your soil probe with tape at the 6 inch mark can make this easier. Check out the video to see how to use your soil probe, and how much of your full sample you will send to the lab.
“Odd spots” need to be sampled separately so that they don’t cause problems for the rest of your samples, and so you can find out what might be wrong in that area.
When Should You Sample?
Phosphorous, potassium and pH levels can vary greatly throughout the growing season. That means if you want to compare changes from year to year, you should sample at the same time every year. Testing for pH, potassium and phosphorous only needs to be done every 3 years or so.
Because nitrogen is so dynamic in the soil, sampling to determine how much nitrate/nitrogen to use should be done 30 days before you plan to apply it. The results of these tests are only good for about 60 day.s
Sending Your Sample In
No matter where you’re sending your sample, all labs need the same basic information with it:
• Your name and Address or email address so they can contact you.
• What you’re growing – this allows the lab to match up what your soils have with what your plants need so they can make a good recommendation.
You’ll also want to add the name of the pasture or field you sampled so you can keep track of the needs of different parts of your operation.
Dr. Funderburg includes other great tips in this 8:24 video. Enjoy!