When you go to a restaurant and order the beef stew; how much salt do you add?

Depends on how salty the stew is when served.

There is no way to know how much Nitrogen to add to your soil until you know how much exits initially.

Professional soil test are not expensive and the best way to go.

I use Tomato Tone which is an organic fertilizer and directions are on the bag both for the row and plant.

If you do a search for "Earl's Hole" method you may get some idea BUT you still need a soil test.

I have been call worse than parsimonious; yet I get a soil test every year.

Near perfect soil makes gardening much easier.

You can experiment.

Use 1/2 cup of 10-10-10 on one plant
Use 1/2 cup of 5-10-10 on one plant
Use 1/4 cup, etc.

Use nothing on one plant.

Watch color, growth, production, etc. and figure what works best for you.

Good luck,

John