Hi Angela, thanks for the question.

There are plenty of reasons that your root crops are not developing.  Looking at your soil test the lower phosphorous levels and potassium levels are low and magnesium and pH are high.   All these things interact with each other, so it is difficult to assess. Bringing these into balance may help.  Phosphorous does affect root development. Another factor is the temperature.  These crops like cool temps and should be planted early mid to late April (larger varieties later).  Given the higher temps seen last year this is a possibility.  Prolonged cold temps can also affect the roots.  Adequate irrigation is another critical factor in root development.    High nitrogen can inhibit root development.  You may experience excessive leaf growth if too high.  Crowding and heavy soil can impede root development.  Of the possibilities, low phosphorous, planting time, and water seem most likely.   Check out the following links:

Changing the pH of Your Soil | Home & Garden Information Center (clemson.edu)

More reasons for soil testing - Agriculture (msu.edu)

I hope this is helpful.

Hi again,

Just wanted to let you know that Gypsum does not lower pH and can reduce potassium which is already low.  Check out this link:

Gypsum as a soil additive: use it or lose it? - MSU Extension

Hi Angela,

There is not a good way to reduce magnesium. Toxicity from magnesium is most likely not an issue if other plants are growing without problems.  Adjusting the pH down to 6.5 will inhibit magnesium uptake.  pH is best reduced with sulfur, but it does takes time.  A pH of 6.5 is a good target pH since most vegetables (potatoes like it lower).  A 7.5 pH although high is not exceptionally excessive.  When adjusting be careful not to overdo it. This is a slow process, and more isn't better.  It is preferable to bring it down slowly.  No more then 5-10 lbs. of sulfur should be applied at any one time with 2-3 months between applications.  Taking into consideration of your Cation Exchange Capacity (CEC), you are probably looking at ~16 lbs of sulfur total divided into 2 or 3 applications. Check out the following links.

Managing Soil pH in Horticultural Crops | Small Farm Sustainability (iastate.edu)

After You've Tested Your Garden Soil, Then What? | Horticulture and Home Pest News (iastate.edu)

Clemson Soil Acidification Calculator

Hi again,

Sounds like you have it under control! I hope you have good results.