Ever noticed that when you water your lawn/garden it politely says “thank you,” but essentially doesn’t look much different unless it was drought stricken to start? But then it rains, and it’s like the plant version of the “Hallelujah Chorus”! The plants not only perk up, but they practically leap up and suddenly you have new growth, flowers or a need to mow your lawn. Most people notice, but otherwise don’t think much of it, but some of us look at this dichotomy and think “What? Isn’t my water good enough for you? What does rain water have that mine doesn’t, or is it the chlorine slowing it down?”
Well, here’s the answer, and it isn’t the chlorine in tap water, but what air is composed of:
Most people think that air is primarily oxygen, since this is the gas we need to survive. However, the major component of air is nitrogen – 78.09% of it! Nitrogen is completely inert, meaning it the under normal conditions it has no positive or negative effects on our bodies (unless you scuba dive, but that’s not part of this post). Oxygen is only about 20.95% of the air we breathe, with the final 0.96% made up of trace gasses such as carbon dioxide (0.03%) and argon (0.93%).
So what does this have to do with plants? Nitrogen is a natural fertilizer, and when it rains it washes out of the air and fertilizes the plants as well as giving them a drink. (What a cool way God has designed to both water and feed the plants!)
Why doesn’t the atmosphere doesn’t contain a higher concentration of oxygen? It wasn’t designed to, for (at least) 2 excellent reasons:
- Breathing pure oxygen for extended periods of time leads to oxygen toxicity (and a particular danger for premature babies that is better understood now than in the past);
- oxygen is a potent accelerant, so if there was a greater concentration in the air, fires would be more common and more intense.
As Bill Nye, the Science Guy used to say, “Now you know…!”