My wife has taken several fallen tree branchs and placed them in our already tilled autumn garden to burn off and add phosphorus to the soil. Does this work?? {before we get out the rake, matchs, and water hose]

Sure, commonly done. Just do it on a still day, and if you live in a city limits, make sure you have a fire permit. After the fire is out, make sure and spread the ashes over a wide area, too much in one spot makes it too "rich" or can burn the plants. But I've done that several times, making sure to spread the ashes, or put ashed from my burn pile in the garden. As long as they are spread out, and tilled in, work well.

Fire (pot) ash is a great addition to any garden.

We live rural and burn rubble all year round. In the end the ash is added around trees and in the flowerbeds.

There is actually a huge Bonn fire arranged for tonight !!!!
Bring hot dogs and marsh mellows, your drink of choice and a chair.

lighting fires near a house can never be a good thing.