Lightning will produce fertilizer. Tianshui is rain.

Your question is so confusing, haha. "Thunder and lightning will produce fertilizer" means that about 1-2 tons of nitrogen will fall to the ground with raindrops every time it thunders. The fertilizer here refers to nitrogen fertilizer.

"Tianshui is rain" is true, but it has always been called so. You should know that there is a saying in The Journey to the West called "passive water".

Acid rain, don't even think about it, of course it will be harmful to plants. How can you water the flowers with acid rain?