South Texas is a hot and dry land, and when a good rain comes, our plants rejoice. But rain brings more than water to replenish the countryside. Rain also contains fertilizer.
The air in the atmosphere is 78% nitrogen. Plants require nitrogen to grow, but they can’t process the inert nitrogen gas in the sky. It takes an enormous blast of energy to break apart those nitrogen molecules and convert them to a compound that plants can use.
This is where lightning comes into play. A lightning bolt is 50,000 degrees Fahrenheit, hotter than the sun, and contains up to a billion volts of electricity. A single lightning bolt can stretch for miles as it tears apart the sky with its power.
The unbridled energy of lightning shatters the nitrogen molecules in the air. Some of the free nitrogen atoms combine with oxygen to form compounds called nitrates that mix with the rain.
These nitrates are a powerful natural fertilizer. Raindrops carry the nitrates to the ground in a soluble form that plants can absorb. This process is called atmospheric nitrogen fixation, where lightning creates fertilizer in the sky.
The falling raindrops also capture other particles in the air, such as dust and pollen. The rain delivers this biologically rich material to the soil while cleansing the grit and grime from the leaves of plants.
The rain gives its water to the thirsty land, but it is the lightning that adds fertilizer. We can water our gardens ten times and not do as much good as one lightning-charged rainstorm. Our lack of rain in South Texas costs us more than the loss of water—we also lose nitrogen in the soil.
A different method for fixing nitrogen into the soil is to plant beans in your garden. Beans use biological nitrogen fixation, which occurs in the roots, to quietly fertilize the soil. Planting beans to fix nitrogen is not as thrilling as lightning, but is more dependable in a land without rain.
But when the storms do come, we love the lightning for more than the show of lights. Farmers love lightning for all of those nitrogen-charged raindrops that fall from the sky as fertilizer for the plants in our gardens.
(All of these beautiful pictures of lightning are used courtesy of Tony Laubach, one of the premier storm chasers in the country. Tony is the son of our friend and KEDT radio host Liz Laubach. Please click here and like Tony’s Facebook page, and let him know his friends are wishing him the best at the beginning of this storm season!)