Technically correct, the best kind of correct! Of course, the way the nitrogen gets into the soil (as ammonia) is due to nitrogen fixing bacteria that do in fa

Technically correct, the best kind of correct! Of course, the way the nitrogen gets into the soil (as ammonia) is due to nitrogen fixing bacteria that do in fact get their nitrogen from the air. So the tree gets nitrogen from the air in a roundabout way. (Earth's atmosphere is 78% nitrogen, so as a bacterium you'd be a bit silly to ignore such a rich source) Same is true of Hydrogen and Oxygen of course, which fall as rain and enter the soil first, before being taken up by the roots.