“Lightning is another natural way. Nitrogen in the atmosphere can be transformed into a plant-usable form, a process called nitrogen fixation, by lightning.
Each bolt of lightning carries electrical energy that is powerful enough to break the strong bonds of the nitrogen molecule in the atmosphere. Once split, the nitrogen atoms quickly bond to oxygen in the atmosphere, forming nitrogen dioxide.
Along with the lightning in the cloud are cloud droplets and raindrops. Nitrogen dioxide dissolves in water, creating nitric acid, which forms nitrates. The nitrates fall to the ground in raindrops and seep into the soil in a form that can be absorbed by plants.
Lightning does add nitrogen to the soil, as nitrates dissolve in precipitation. This helps plants, but microorganisms in the soil do the vast majority of nitrogen fixation.”
https://wxguys.ssec.wisc.edu/2018/07/09/lightning/
Seems like it wouldn’t be a very effective use of energy. Probably better to just mulch with chopped legumes. I remember seeing somewhere that thunderstorms were worth around 10 lbs of nitrogen a year per acre vs 30+ for legumes.