You can buy a home test kit that will tell you the levels of N-P-K
That's all you need to get yourself started in the right direction.
One thing that wasn't mentioned is regarding the drainage of the soil. If you are in an area that is poor in drainange. Less applications will do. If you have good drainage then as many as 4 or even 5 applications (more on the 5 applications later)
In either condition slow release will be the only fertilizers you will ever use!!
A slow release of 50% or more.
If your muching less fert is needed during the season. The amount of N mentioned above is accurate 3-4 lbs per 1,000 annualy.
Now you can either do those apps 3, 4 or 5 times a season, as long as your annual is within the limits.
We do 5 apps. 4 in season and a winter application. All 8 weeks apart. We do the apps at reduced rate and do an annual total of N applied of around 5lbs per 1,000.
Now also your fert of choice is also dependent on the time of year. For disease suppresion you will use a higher K.
Your local supplier will know about the average soil conditions and will make recomendations. Truth is those people behind the counter should be your BEST friend, or they will be