Peter - in looking at your soil test results, I see the Potassium and organic matter levels are low.  The pH and other indicators are fine for dune grass.

The fertilizer ratio recommended is 1:2:4 which is a guideline when purchasing a general fertilizer.   As the first example shows, you could purchase a product with higher Potassium (5-11-26) which will address the low Potassium level while also providing the other nutrients.  After your purchase a product, come back to the MSU soil test site and enter the numbers into the Fertilizer Calculator (found under Tools) and the site will calculate how much of that product to apply in one year over 100 sq. ft.  Remember to pro-rate the amount if your area is less or more than 100 sq. ft. 

You should also focus on increasing the organic matter in your soil.  I am including a link below that will provide you with more details on the ways that can be done.  

https://www.canr.msu.edu/resources/smart_gardens_begin_with_healthy_soil

Good job starting with a soil test to better understand the health of your soil  Hope that helps.