Hi Jill,

I have been assigned your question regarding your soil test results and look forward to helping you. Would you please send me pages 2-3 of the test results. It would also be helpful if you let me know what you're trying to grow and how your results were last year.

Removal of the soil will not be necessary. If you would like to learn more about the subsoil on your property you can visit: https://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx .

After creating an area of interest (your property) you can explore the information provided. Depending on the size of your property, you may have locations with different subsoils.

Although the subsoil information isn’t necessary to advise regarding the 3 page test results, if you take the time, please send it along.

Enjoy

Jeff Nummelin

Extension Master Gardener Volunteer

Hi Jill,

I noticed on the test results your PH is 7.4. Most vegetables thrive best when the PH is 5.8 to 6.5. This is perhaps a greater challenge to healthy growth than the high nutrient values.

Let's start with the pH, since that's going to make the biggest difference to your plants. You may probably know this, but just to be sure: pH is on a logarithmic scale (0 to 14, most acidic to most alkaline), so 7.4 is ten times more alkaline than a pH of 6.4.....and 100 times more alkaline than a pH of 5.4. Plants thrive in the middle of their ph range -- that's where they can best absorb nutrients from the soil. This is a spectrum -- so they can survive on either end of (and even for a while beyond) their range, but to give them a chance to shine, you'll want to try to get the soil pH down.

In the "Comments" section of your soil report, you can see the recommendation to add elemental sulfur to bring the pH down. This can take time -- even a few seasons. You can't add too much at a time because you might burn plant roots (you're adding acid...). You could opt to use aluminum sulfate instead (also an acid) -- it works a bit faster but isn't on the standard soil report print-out because it costs a little more when you have large areas (partly because you need to use a little more) and isn't recommended for soils that already have high aluminum or sulfur content -- your soil looks good here. So see what your local trusted garden center has and recommends for lowering soil pH and then be sure to follow the directions carefully to avoid burning plant roots.

A couple of things you can do while slowly working through the time it takes for elemental sulfur or ammonium sulfate to lower pH:

• Add Canadian sphagnum moss -- you can use it as, or with, your mulch around the base of the acid-loving plants. (Note: be sure it's Canadian sphagnum moss. You can buy regular peat moss in the same big bags. Canadian sphagnum peat moss has a pH of 3 - 4.5; but the regular peat moss is neutral -- closer to a pH of 7.0.)

As you note: the second standout item in both of your soil reports is the high level of all three macronutrients: phosphorus, potassium and magnesium. Yes: we do see this surprisingly often. I've noticed that folks who use a lot of compost often have high macronutrient readings -- but it might just be the history of your soil. The good news is that this isn't horribly bad for your plants -- over time they will take up the excess nutrients and regain an equilibrium here. But it tells us that you don't want to add any more phosphorus or potassium anytime soon. If you annually apply compost: that's OK if its Ph in range; but your soil is already high in organic matter so it's not needed. You may want to check the PH of your compost and add coffee grounds if it is too high. The key message is: don't add fertilizer that will increase the amount of phosphorus and/or potassium in your soil . Most commercial garden fertilizers are pretty high in phosphorus (N-P-K: Nitrogen, Phosphorus & Potassium). You CAN add nitrogen-- it washes away if the plants don't need it; but phosphorus & potassium are persistent and phosphorus, in particular, is bad for our watershed (blue-green algae, et al). Some fertilizers that provide nitrogen without a lot of potassium and phosphorus are:

• Pro-Booster 10-0-0
• Blood meal 12-0-0
• Chilean nitrate 16-0-0

Again: if you have a good local garden center: ask their advice for low-to-no phosphorus & potassium fertilizers.

I don't think these results mean that your soil is "contaminated" (although there is a separate test for lead...) and the proximity of the road is probably a greater risk for salt contamination -- your sodium levels are a tad high, but not terribly bad. You might know the history of the soil better than I possibly can: farmland? (Excess fertilizer...) Even simply recent additions of compost? Bottom line is that bringing the pH down will help your plants and you now know to avoid adding any more phosphorus and potassium until you have another soil test that shows that you need those macronutrients.

Everything else in your soil reports looks good.

Also, I recommend winter rye for a cover crop this fall. It overwinters and starts to grow in the spring when you can turn it in before you plant. It enriches the soil and begins to help balance things out for you. I have attached an article on cover crops to give you an introduction to ongoing utilization of green manure for your garden.

Once ready to plant next spring, a nitrogen boost for your plantings will help them get a good

start. I recommend blood meal, a concentrated nutrient so be sure to apply as directed.

If the test report missing pages discussed information I didn’t cover or should you have further questions regarding this recommendation or your soil survey findings, please do not hesitate to ask.

Enjoy Gardening

Jeff Nummelin

Extension Master Gardener Volunteer

Hi Jill,

Thankyou for the kind words. I may have provided a prescription without discovering the cause. Your initial question pointed out your use of a raised bed. Is the bed new or composed of mostly compost? Does your surrounding soil have a more suitable pH? If the answer to both of these questions are yes then I would rebuild the raised bed with more of the surrounding soil and less compost. More importantly, check the compost pH prior to adding it to your garden.

My well water pH seems to spike in the spring and I need to lower it to successfully grow seedlings. I also use my pH probe to understand where different plants will thrive in different locations. Thinking about your question reminds me that I should be checking my compost as well. Although a good probe cost $200, I would not be able to succeed without it. Another option is to send another soil sample from soil surrounding the bed. If the answers to the questions above are no and you have to lower the pH, do so before planting anything in the bed.

Best wishes,

Jeff

Hi Jill,

I found an informative article you can find at https://extension.psu.edu/soil-health-in-raised-beds. Although it won’t help with your current elevated pH you might find it useful in the future. It recommends 70% soil, 30% compost.

I too have a heavy clay based subsoil. Although I would like to have both, I don’t think I would trade it for one more sand based. Both can be improved by adding organic matter. While I treat both my raised beds and field rows the same (no till Broad Fork, Crop Rotation, Cover Crops), the raised beds perform superior. I started my raised beds by digging to hardpan (In my case 3”) , retaining the topmost 1” into a pile and the remaining into another. Placed my raised bed below topsoil level on the hardpan and filled it with the larger pile mixed with about half as much compost. Then spread the soil from the topmost 1” on the bed and dressed it with a little more compost.

Based on the bed's history, I suspect the recently added Compost had a high pH and the bed does not contain enough real Vt soil. Was wood ash added to the compost? Wood ash elevates pH. In the future try to make sure to not add compost with a pH out of range.

This article https://www.extension.purdue.edu/extmedia/ho/ho-241-w.pdf offers multiple options for lowering pH. If you would like help determining how much of your chosen remedy is needed, please forward me the size of each of your raised beds and I will be happy to calculate amounts needed. If the beds have room and need topping off, maybe we should run the numbers to learn how much peat is needed.  I try to not use peat due to its environmental impact.  Otherwise elemental sulfur or aluminum sulfate should suffice.

Have a nice evening

Jeff