Hi Joanne,
Thank you for your question. Could you answer a few questions for me so that I can help you more effectively. Are you growing flowers or vegetables? Do you use lots of manure or compost heavily in your garden beds (increases phosphorus).
Since phosphorus levels are excessive, avoid using manure composts and other fertilizers and amendments containing phosphorus. Add more carbon (“brown”) ingredients to any compost you make. Growing beans or peas or fall legume cover crops helps increase nitrogen in the soil and decreases phosphorus levels.
The high Mg is generally less of an issue. Do you add Epsom Salts (Mg) to your crops (some use this for peppers)?  If so, don't use this. Are you noticing stunted growth or browning on the leaf edges of your plants (a sign of excess Mg which can deplete micronutrients)? If not, I would not be concerned. Plants are tolerant of a fairly wide range of Ca, Mg, and K in the soil.
I am enclosing some references that should be helpful. One is a question very similar to yours.  I am also linking in another Master Gardener as a collaborator who has particular expertise in soil test interpretation.
https://ask2.extension.org/kb/faq.php?id=749014
https://www.uvm.edu/sites/default/files/Extension-Community-Horticulture/InterpretingSoilTests.pdf

Gypsum could be  a good solution to your problem. It decreases Mg levels and increases available Ca, which could help with the browning and yellowing leaves. It also decreases compaction, and enhances soil permeability without affecting pH.

In vegetable gardens, the recommendation is 20-30lb granular gypsum per thousand sq feet of soil. Spread this on top of the garden bed and water. The addition is supposed to be good for 3 years and results improve each of the three years from this one addition.

I have never used this myself and would appreciate feedback from the collaborator before you embark on this since some state garden extension sites recommend use of gypsum and some do not.. You should hear in the next few days. Thanks for your patience.

Hello Friends,

Ricky the collaborator here! Gypsum would absolutely be a fine addition; it's benign for almost all soil types, so at worst it would do nothing.

You have a great profile of micronutrients (the excessive P and Mg are probably from the manure additions, but this is fairly common in VT regardless of additions, so it's hard to say), and the gypsum would help with the pH and, by extension the cation exchange capacity (CEC in the soil report) to make those nutrients more available to your plants.*

I totally back up Betsy's advice!

Additionally, with the crazy rain this year, a lot of soils have been saturated with water at key points for plant growth and are suffering from various nutrient deficiencies by no fault of the gardener!

Over time, the macro-nutrients should come more into balance as long as there are no more heavy manure or compost additions and we have a year or two of somewhat normal rain.

I hope this helps! Happy gardening!

*No need to read this, just an incredibly nerdy note: The super cool thing is that the cation exchange allows plants to not only access certain minerals, but actually allows the plants to summon more soil microbes to make the minerals more available right around the roots by sending out signals (root exudates) to summon the right microbes which, in turn, changes the pH and in-turn changing the cation-exchange capacity in a positive feedback loop! OK, I'm done.

That calculation is correct for a vegetable garden. The best time to use gypsum is when a bed is being prepared before planting.

Leaves will add phosphorus and magnesium. Pine bark would be a better mulch and could also lower the pH of the soil.

You probably already thought of this but I would recommend another soil test next spring after you have made these adjustments.

Best of luck!