Daniel Hudson, UVM Extension Agronomist
Have you ever felt like you should check some health metric, but didn’t want to face the possibility that the news might not be favorable? If my cholesterol is high, they are going to put me on a vegetarian diet! Sometimes, it is just better not to know. What I don’t know can’t hurt me!
In the realm of cropping systems, it goes more like this: If I soil test this field, I’m afraid the report will 1) tell me that I need to spend $200/ac to fix my soil fertility problem, and 2) confirm that my brother was right – that we have been losing massive amounts of yield and quality that could have been prevented. I’d rather not know!!
While ignorance is bliss, it is also expensive. The cost of soil testing in terms of time and lab fees is a pittance compared to annual reductions in crop yield (often over 30%) and forage quality that result from nutrient deficiencies. A soil testing regimen will inform you of the status quo as well as the direction the soil fertility is headed in a given field. Soil fertility has implications for crop yield/inventory, forage quality, plans for spreading manure, the value of land you might rent, legal compliance, and more. Every professional farmer should own and use a soil probe or auger.
‘The fertilizer guy has someone soil test for me – for free! Why would I get my own probe?’ Whoever you delegate the task to, if anyone, you need to be confident that they have your best interests in mind and that they are competent. Even if it is your best friend doing your soil sampling, you should still own a good probe so that you can check up on things once in a while. Aside from being essential for routine soil testing, soil probes are also helpful for efficiently diagnosing in-season agronomic problems when they arise, such as, ‘why does the grass grow so well over here, but looks terrible over there?’
What kind of probe should I get?
A wide array of soil testing equipment available online – I do not recall ever seeing a ‘real’ soil probe in a store. When considering the options, note that:
- Short probes are less expensive, but require much more bending. This is okay for a few samples, but after a whole day of sampling you might reconsider your frugality.
- Thin-walled probes are less expensive and light to carry around, but can often kink and break when the soil is hard and in rocky fields.
- Some probes have replaceable tips.
- Some soil probes open along the middle, which allows for easier extraction of the cores, especially with certain soil types and soil conditions. I don’t have one of these, but I like the concept.
- Having a step on the side of the probe can make it easier on your wrists and elbows but, if the probe is flimsy to begin with, this type will probably break more quickly.
- Some probes are designed with a longer side-cut-out that allows you to take (and remove) 12 inch (or deeper) soil cores. This is necessary for pre-sidedress nitrate testing (PSNT).
- You can even mount a slide hammer on some soil probes on the market! This is good for dry soil without rocks. If you have rocks, the slide hammer will ensure that your soil probe (at least the tip) will be destroyed in short-order.
Like everything these days, there are lots of options. I have not even covered soil augers, which some prefer. As with most things, you get what you pay for.
By listing these online sources of soil probes, augers, and other soil testing equipment below, I am not implying any sort of endorsement of one over another. There are, no doubt, many other great sources of this equipment online that I have not listed below. If you are in a pinch and need a soil probe before yours will arrive, most Extension offices that house an agronomist can lend them out. You can also check with your local Conservation District or NRCS office.
An incomplete list of online sources of soil testing equipment: