What does organic food have to do with sustainability and green living?
For many people who are passionate about environmental issues, sustainability absolutely requires organic farming. Especially sustainability in agriculture.
They tout the health benefits and claim that conventional farming destroys the soil and pollutes water.
They disapprove of factory farming. They often take a dim view of industry in general. A dim and short-sighted view. In fact, organic farming on a large scale is factory farming. It is the organic farming industry.
Like any industry, the organic farming industry has its own spin. It seeks to persuade the public that it is better than the alternatives. And like any industry, it can easily overstate its case.
There is no absolute best choice between organic and conventional farming. Both have environmental advantages and disadvantages.
Which uses less energy? Conventional or organic farming?
Organic farms consume less energy than usual farms. That fact may be its single strongest advantage.
According to one study, conventional farming uses 71% more energy. Using petroleum-based fertilizers account for most of the difference. Besides being made of oil, they require energy to manufacture and transport them.
Organically grown crops have the same requirements for nitrogen and other nutrients, but organic farmers use composted manure. They rotate crops that require lots of nitrogen with nitrogen-fixing crops like beans or peas.
Usual farms use pesticides and herbicides that organic farms shun. That adds a little bit to their greater energy use.
Lower energy use adds little to sustainability in agriculture, however. Energy in farming represents only about 35% of the energy embedded in our food. The rest comes from transportation, cooking, and garbage disposal.
Which is better land use?
Most farmers grow the same crops in the same fields every year. Organic farmers rotate crops.
That, too, is a big advantage of organic farming. But regarding land use, it’s the only advantage.
Organic farms produce only about 50-80% as much food as usual farms. Therefore to harvest the same amount of food as a conventional farm, an organic farm requires more land. As the world’s population grows, so does its demand for food.
Today about 800 million people worldwide suffer from malnutrition. About 16 million will starve to death. If only organic farms existed on the same amount of land, we would have 1.3 billion malnourished people.
Environmentalists have long watched in horror as forest land is cleared to make room for farms. Especially when it’s rain forests. Clearing forests decreases a region’s biodiversity and the habitats available for wildlife. And that’s only one bad consequence.
If not another acre of land were converted to farmland, agriculture would still be using 35% of the world’s ice-free surface. All of the world’s cities and suburbs occupy less than a 60th of that space.
What would it mean to replace conventional farming with organic farming and growing the same amount of food? It would require digging up 20% more of the world’s ice-free land, an ecological catastrophe. Organic practices are not sustainable agriculture on a global scale regardless of whatever advantages they might have locally.
Land use means more than the amount of land needed for farming. Does organic farming, specifically organic fertilizer, take better care of the soil? No.
The choice is not between natural or synthetic fertilizer, but between organic and mineral fertilizer. Organic fertilizer contains carbon. Mineral fertilizer does not. Some mineral fertilizers are natural (potassium chloride, for example). Some organic fertilizers are not. Manure, for example, is natural. Composted manure requires human intervention and is therefore synthetic.
Fertilizer does not poison the soil if it is applied correctly. Excessive application of any kind fertilizer leaches into groundwater or runs off into waterways. It also increases emission of nitrous oxide and methane. These greenhouse gasses are at least an order of magnitude more powerful than carbon dioxide.
Crops retain 30-70% of the fertilizer applied to them. It was long assumed that the rest was lost to runoff, erosion, leaching, or denitrification. As it turns out, however, soil microbes ingest nitrogen from fertilizer before the crops can. They actually make soil richer by converting nitrate into organic matter.
Organic fertilizers are lower in nutrients than mineral fertilizers. Therefore, mineral fertilizers make plants grow larger. But they do not deplete organic matter from the soil. If crop residues are plowed under, their decomposition actually adds more organic matter to the soil than the smaller organically grown crops.
Plants don’t care if their nutrients come from organic fertilizer or mineral fertilizer. It matters to the soil, however. Optimal land management requires both kinds of fertilizer, because they offer the soil different benefits.
Exclusive use of organic fertilizer works only in nutrient-rich soils. Depleted soil needs mineral fertilizer. Most mineral fertilizer is synthetic. Organic farming will not work in bad soil. In sub-Saharan Africa, cattle are so undernourished that even their manure does not fertilize the soil efficiently.
Pesticides and organic farming
I said earlier that ordinary farming uses pesticides organic farming shuns. That doesn’t mean organic farms shun all pesticides.
They liberally use pesticides like Bacillus thuringiensis (Bt), a highly toxic insecticide derived from soil bacteria.
It would be better to encode the toxin into the genome of the crops.
That’s right. The much vilified GMOs potentially decrease pollution and increase nutritional value.
The organic farming industry claims that GMOs are totally evil and automatically render the crops unfit for human consumption. That is perhaps the most dangerous of organic myths.
Are organic pesticides any less toxic than synthetic pesticides? And do pesticide residue on food pose a hazard to human health? Again, the answer to both questions is no.
According to the EPA, humans should not be exposed to more than 0.02 milligrams of Malathion per day per kilogram of body weight. Malathion is a synthetic pesticide. By contrast, it has set an upper limit of 0.004 milligrams for Rotenone, a common organic pesticide.
In other words, Rotenone is five times as toxic as Malathion. Other common synthetic pesticides are also less toxic than Rotenone.
Synthetic pesticides have been designed to be more effective than natural pesticides at lower doses. All organics break down faster. It takes higher doses for them to work.
Some tests suggest that organic produce has less pesticide residue than conventionally grown produce. But they have tested only for synthetic pesticides. Tests that measure both natural and synthetic pesticides find measurable pesticide residue on between 15-43% of organic samples.
The US Department of Agriculture tested 12 conventionally grown fruits and vegetables. The tests found average levels of 10 of the most commonly found pesticides.
USDA researchers estimated the average amount of each pesticide that Americans typically ingest in the course of a day. It compared those estimates with the EPA’s exposure limits.
The pesticide most commonly detected on apples, widely considered the most pesticide-contaminated fruit, is called Thiabendazole. The EPA’s limits are 787 times more than the amount Americans eat in a single 24-hour period.
Other pesticides give even less reason to be concerned about poisoning. And the EPA limits are set at at least 100 times lower than the lowest amount that causes any sign of harm to test animals.
Farmers and people who live near farms should take care to minimize pesticide exposure. But no one will receive dangerous levels simply by eating produce.
Meanwhile, more than 50 years of studies have compared conventional and organically grown crops. They have not found any evidence that organic food is more healthy or nutritious. Blind taste tests also present no evidence that organic food tastes better.
There is no need to take sides while the usual factory farms and organic factory farms hurl insults at each other. Both have advantages and disadvantages. Neither is sustainable as currently practiced.
It ought to be possible to introduce good organic farming practices into conventional agriculture and good conventional farming practices into organic agriculture. That way we’d have a better chance to achieve sustainability in agriculture and produce the food the world needs.
Organic vs Conventional Farming: Which Uses Less Energy? / Brian Palmer, Washington Post, November 12, 2012.
Myth Busting 101: Organic Farming > Conventional Agriculture / Christie Wilcox, Scientific American Blog, July 18, 2011.
5 Fertilizer Facts that Dispel Myths / Pedro A. Sanchez, Huffington Post, August 14, 2015.
Organic Shmorganic: Conventional Fruits and Vegetables are Perfectly Healthy for Kids / Melinda Wenner Moyer, Slate, January 28, 2014.
Organic farm shop. Some rights reserved by Andrya Prescott.
Organic produce. Pubic domain from Wikimedia Commons.. https://commons.wikimedia.org/wiki/File:Organic_Produce.jpg
Do not spray sign. Public domain from Wikimedia Commons.