Our Slice of the Carbon Cycle: Down on the Farm

by Alex Taylor

Looking out an airplane window, it is shocking to see how much of the Earth’s surface is farmland – all those irrigated circles and squares, stretching on to the horizon.

If this land was not tilled, sowed, sprayed, guarded and harvested – if it was not teased into the tidy, geometric, human shapes we see from the plane – it could be dales and thickets, marshes and hummocks, teeming with a million varieties of vibrant, exuberant, wild life, butting horns and dancing frenetically, emerging from wombs, eggs, seeds and spores, living and dying and gradually evolving, as life has for hundreds of millions of years before we were here.

Farmland is obviously essential to feeding, housing, and clothing the billions of hungry people around the world. We need this land to provide for our own, but we should recognize what we’re plowing under, act as responsible stewards, and leave room for our biotic brethren. This is not only a sentimental issue; we rely on wild ecosystems to keep our air and water clean, pollinate our crops, and provide many other “ecosystem services.”

This series has focused on our slice of the global carbon cycle, which scientists clunkily refer to as Human Appropriation of Net Primary Productivity (HANPP). The carbon cycle is powered by plants and algae using the sun’s energy to turn carbon dioxide into food for us and for wildlife. There is a limited amount of surface on Earth for it to happen. If we want to leave space for wild things and still provide a decent life for all humans (we do!), we need to be as efficient as possible in our use of land. So far, we have discussed how growing population adds to this challenge, and how we can redesign cities to be more efficient and greener.

But the real meat of the issue, as you can tell by the view from your airplane window, is farmland.

The farm of tomorrow

Come from above to measure moisture. Photo: Henrique Boney

If we are going to use land that would otherwise be natural habitat, we should be making sure to get every ounce of food we can out of it. New technology can help us out here. We live in a time when massive amounts of data about soil and microclimate conditions can be collected and analyzed, and data-driven agriculture can allow us to make smarter choices about how we farm. Drones (unmanned aerial vehicles) can collect this data as well as administer fertilizers and pesticides more precisely.

Genetic modification of crops can theoretically be used to increase yield, and also to expand agriculture into marginal lands that are salty or dry. Unfortunately, most GMO’s currently on the market have been engineered by companies like Monsanto only to be resistant to their branded pesticides, leaving many potential benefits of GMO’s on the table. Though the question of whether our current crop of GMO’s have increased yield is hotly debated (along with basically everything else about GMO’s, from legitimate concerns to facebook-powered paranoia), we certainly haven’t hit a home run here. This (so far) squandered opportunity serves as a good warning: though technological advances can help us improve agriculture, we must be thoughtful about how and why we use them.

Back to Basics

Many of the technologies and practices we can use to make more efficient use of land are not particularly new. Improving food distribution systems, so that food does not rot in the field, on a truck or in a grocery store, would go a long way. Rotating crops (planting different crops sequentially in the same field) can increase yield substantially, and enhances the soil structure and carbon sequestration. Adding in companion species, and encouraging symbiotic relationships with soil fungi and bacteria, can increase yield without reliance on fertilizers.

Crop rotation

Many other practices, such as adding buffer strips around farmland, do little to reduce our use of the carbon cycle but have other serious environmental benefits like reducing pesticide drift and fertilizer runoff. Reducing the extent of monoculture (acre upon acre of the same crop) and increasing the biodiversity of farmland can help contain pest outbreaks, and has many other ecological benefits that we will discuss later in this series. All these low-tech, environmentally beneficial farming practices have been de-emphasized in our economic system, in which current agricultural systems are distorted by perverse subsidies and blind to the environmentalnegative externalities.”

From Farm to Table

Not all wasteful food decisions happen on the farm. For example, people in the rich world simply throw out an enormous amount of food every year. Culturally, the kind of food we choose to purchase and eat also has a big impact on land use. In addition to other environmental concerns like pesticide use and fertilizer runoff, some crops produce much more food per acre than others. Plants in general are much more efficient than animals; a cow only turns a fraction of the food it eats into meat, with the rest devoted to keeping its heart pumping and its body warm. Each pound of beef you eat took about twenty pounds of grain to produce. Eating less meat can significantly reduce the amount of carbon you emit, and the amount of land needed to feed you.

Vertumnus, by Giuseppe Arcimboldo

I wouldn’t suggest that we should all eat only sweet potatoes to save the environment; there are many other priorities to consider when choosing what to eat, like taste, price, culture, and health. Even the environmental consideration involves a lot of factors: pesticide and fertilizer use, “food miles” travelled to get to your table, packaging, and others. These complex questions are just now getting disentangled in a way that’s accessible for the average consumer. A change of culture is key.

Growing Hope

Humans need to set aside otherwise wild land in order to grow the food, fiber, energy and building materials we need to provide a decent life. But there are many ways to do that. Our current agricultural system is plagued by inefficiency, from food waste to farming strategies that maximize profits at the expense of the environment. As was the case for cities, farms were not designed with environmental efficiency in mind. There are many relatively easy solutions that we can put in to place today.

In some cases, new technologies like agricultural drones can provide a way forward. In others, policy changes can change the incentive structure to encourage good environmental stewardship through low tech practices like crop rotation and companion planting. One of the biggest changes that we can make, and that you can make, is a cultural one. Eating less meat, or reducing food waste by planning out your meals, can make a difference. Composting the waste you do produce can cut down on landfill.

If we want to leave some space on Earth for wild ecosystems, there are many opportunities to reduce the amount of land under plow. We’ve already built a global system of agriculture and food distribution. If we plan intelligently and act on technological, political and cultural levels, there’s no reason that this can’t be improved and updated to reduce damage to natural ecosystems while still delivering you delicious meals at a reasonable price. Are you going to finish that?


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