Gardening with science Part I: eat and be eaten

Everything is recycled, folks. Including us.

Science helps me to appreciate the role of plants in feeding us and maintaining our health and environment. Paying attention in high school biology class helped me begin to appreciate how plants and people are all part of the processes that cycle nutrients throughout the living and nonliving parts of the Earth.

Here's a plant that eats animals. Photo by Noah Elhardt.
Here's a plant that eats animals. Photo by Noah Elhardt.

So I have absolutely no qualms about making my plants eat other plants.

If you think about it, plants should be great food for each other. They’re built from the exact same nutrients other plants need, minus what they expend or excrete to create themselves. So you can raise plants ‘organically’ by turning them into plant cannibals! Well, not directly; they’re actually relying on decomposers to break down the dead plant matter and release the nutrients in a form that live plants can use. Call that a transformation step – like digestion or cooking – if you will.

If you think about it, people eat other people, too; there are just (in most cases) a few more transformation steps between dead people and people food.

Oh yeah. Plants eat animals, too. ‘Organic’ gardening is not a vegan activity. Plenty of ‘organic’ farming operations use animal products such as fish emulsion (famous for its recent use at CU-Boulder to repel pot smokers on 4/20) and bonemeal, as well as animal by-products like manure. There are some fascinating essays in the New York Times right now about whether it’s ethical to eat meat, and at least one of those essays points out the essential role of farm animals in the production of vegetables.

Not a food chain. A textbook nitrogen cycle (this one's from the US EPA).

Think of the food chain. Eaters of plants (people, cows, etc.) are more concentrated sources of nutrition than the plants themselves. The only comparable alternative to animal-based fertilizers is chemical fertilizer. We consider it artificial (rather than ‘organic’ or ‘natural’), but it’s made from familiar substances from nature, like rocks and air. Ammonia, for example, is made from natural gas and air using the Haber Process. It’s energy-intensive and not the greatest thing for the environment, but there isn’t enough bat guano in the world to compete with it.

[Yes, ammonia production is also essential to the mass manufacture of explosives, and Fritz Haber of the Haber process also oversaw the use of poisonous gases as a weapon during World War I. In case this makes you think science and chemistry are evil, remember that the Haber process made farming possible and starvation a thing of the past in many places where the soil was too poor for ‘organic’ methods to suffice, and that Clara Haber – herself a chemist – purportedly killed herself to protest Fritz’s involvement in the gassing of soldiers. Yes, woman are more moral than men].

It’s doubtful that the U.S. could have developed and grown as a nation anywhere near as fast as we did without the Haber process or something like it. Only now, after we’ve built loads of new infrastructure and technology that make productive farming possible in other ways, are we considering alternative means of food production. But as it did then, it will cost us quite a lot more time and manpower than industrial food production does. Searching every leaf of my indoor plants for aphids is lot more time intensive than spraying them with pesticide, but I have the luxury of time and energy to hunt for aphids because other technological developments made possible by cheap food production make much of the rest of my life more efficient.

An oversimplified piece of the nitrogen cycle illustrating an important relationship between us and our plant brothers.
An oversimplified piece of the nitrogen cycle illustrating an important relationship between us and our plant brothers.
I live in a developed country. I don’t need to produce food on an industrial scale; but I can see how other countries would like to have the ability to do so in order to grow and develop like the U.S. did and enjoy many of the same comforts we do. I am merely trying to grow a little produce to supplement my diet, to reap the spiritual and intellectual rewards of growing my own food, and to avoid paying through the nose for organic produce at the schwaggity schwag Boulder farmer’s market.

In addition to making frugal use of my own vegetarian leftovers to feed my plant cannibals (and my somewhat neglected vermicompost), I plan on using exactly two animal products – eggshells and bonemeal – because they are much richer sources of phosphate and calcium than my produce scraps and coffee grounds. I’ll also add a splash of Epsom salts right around flowering time to make sure I get lots of juicy fruit.

I don’t think ceasing my use of bonemeal will help bring down the feedlot industry. Eating lots more vegetables and much less meat very well might, though. And figuring out and sharing ways to make it cheap, easy, tasty and fun could help as well. So please, read up. I hope you’ll be encouraged to find ways you can transform your own food waste into fresh food instead of throwing it out.