Q.raising the nitrogen level in vegetable garden
How much blood meal is needed to raise the nitrogen level in vegetable garden? We have 3 small areas, one about 25×25, one 4×4, and one 4×8. Our soil test said we were deficient only in nitrogen. We generally use only organic fertilizers.

Blood Meal is an excellent way to add nitrogen to your soil. It is very important to read the application directions on the packaging of the product you intend to use. To much bone meal can burn or kill your young plants.
I also use natural fertilizers in my gardens, and I prefer to mix my Blood Meal applications on the weaker side.
Here is an excellent article to help you get those beds ready for your garden season.
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/blood-meal-fertilizer.htm