This morning, I awoke to the sound of distant thunder. Thunder and lightning have been eerily absent for months, so it was comforting to snuggle a little deeper in the covers and let the rain and thunder nudge me awake enough to start the day.
When I was a child, I had a love/hate relationship with lightning and thunder. I would run to a window at night to see the lightning flash, like flipping a switch in a darkened room. Everything lit up seemed colorless, or at least an electrified monochromatic blue, and I felt like I was getting to see into a mystery not meant for human eyes…a superhuman ability to peer through the darkness. Yet, when I was old enough to read, an article my phobia-filled grandmother had taped to her wall introduced terror into my young heart. The article described stories of people who were struck by lightning, complete with instructions on what to do if you “felt the hairs rising on your body,” a sure sign that you were an intended target of the next strike. I went through a period of years where I would neurotically study the hairs on my arms during every thunderstorm. Thankfully, that phase passed, but I still have an unnaturally quick impulse to move my kids indoors at the first sound of thunder. But, as long as I am safely under cover, I love to watch a storm, and feel the thrill of being close to such a violent display of beauty.
(Warning: I’m about to get all science-y.)
Beauty is always intertwined with science in nature. Lightning has a surprising role in the food we eat. But, first, a little about nitrogen. Nitrogen is a critical element for human life, being the third most abundant element in the human body. We are virtually swimming in it as well, as nitrogen makes up 78% of the earth’s atmosphere. For all of that abundance, however, we are unable to make use of it in its gaseous form (N2 for those interested). It becomes available to us, however, through plants. We literally have to eat the nitrogen we need, either through plants, or from eating the products of animals who have grazed on the plants.
Plants have an ability to make nitrogen available to us in two different ways. Plants known as legumes, such as peas and peanuts, have bacteria that live in their root nodules. These critters are little nitrogen converting factories. They take the atmospheric form of nitrogen and convert it to nitrate (N2 + 3O2 –>2NO3), which the plant greedily snatches up to use and grow. That is why some farmers rotate crops with legumes. These plants help replace the nitrogen in the soil.
The second way that the nitrogen becomes available woke me up this morning. Lightning. As the strong electrical current slashes through the air, N2 is converted to NO3. Amazingly, this process accounts for up to half the available nitrogen in the soil. Nitrate is released from the electrical storm and literally rains fertilizer on the ground. Have you ever read a fertilizer bag? Ammonia’s chemical name is N3. That form, however, has its drawbacks, so a good organic farmer strives to keep a good nitrogen balance through crop rotation and composting – and for some, regular prayers for nature’s fireworks display.