The Debate on Hydroponics: How Should Legislation Define Organic?

Isabella Le Bon

President's Park Greenhouse FBVegetables at George Mason University President’s Park Greenhouse (Facebook: @gmugreenhouse

WASHINGTON–The chinampa raised fields, or what have been known around the world as the Aztec floating gardens, were an early example of mankind’s most innovative agricultural systems. Ancient farmers irrigated fields in marshlands, forming multiple plots of land separated by canals. As populations around the globe increase, archeologists and agricultural scholars sometimes look to our ancestors for solutions to food insecurity.

Today food producers are experimenting with alternative agriculture so they can feed growing numbers, as well as make ends meet. The mega agrochemical company Monsanto is promoting genetically modified seeds as the answer. Others believe the planet’s environmental and food security issues can be reduced through organic farming and more local farms. Intersecting with both organic and local food movements is the rise of hydroponic farms.

Populations are most dense in cities where land is sparse and food deserts, areas of low food security, are one too many. Various nonprofit organizations have come together in American cities to develop and promote urban gardens. Some of which, hydroponics, are reminiscent of the pre-ante floating gardens. Hydroponics are crops grown in pools of water-mineral solutions in greenhouses or hoop houses, large coverings that serve to partially control a garden’s environment.

Water-based growing systems have been the subject of recent controversy within the organic farming community. Some organic farmers who use soil argue that soil is essential to growing organic food. Hydroponic farmers say growing hydroponically is more efficient, sustainable and can even produce more nutritive plants.

Sustainability is perhaps the most significant argument in favor of hydroponics. Without the need for soil, hydroponic crops are well suited to urban farming and further innovation in this field could lead to solutions to rising food insecurity. If hydroponics lose the ability to acquire organic certification they could become less relevant to consumers whose demand for organic food continues to rise. Hydroponics’ potential benefits to public health would be lost.

Many hydroponic producers are certified organic, meaning they follow a set of specific regulations developed by the U.S. Department of Agriculture. These rules, laid out in the Organic Foods Production Act, are considered and often recommended by the National Organic Standards Board, a federal advisory board made up of organic food community members.

In February, the NOSB published a discussion paper on aeroponics, aquaponics and hydroponics especially. The document questions the legitimacy of organically labelled foods grown without soil. In OFPA legislation, soil is a main component of what is called the “organic plan.” Without an adjusted organic plan for soil-less crops, NOSB members consider whether the USDA should cease to grant these kinds of producers organic certification.

Organic soil-based farmers have argued that soil maintenance is an essential part of organic food production. Due to excessive soil erosion, pollution and overgrazing, a lot of earth’s soil lacks the proper nutrients to produce healthy plants. Soil is a mixture of either clay, pieces of rock and organic remains, or dirt. Healthy soil also contains an abundant ecosystem of microbial organisms. These microbes contribute to the recycling of nutrients in the soil and thus to the nutrition of the plants that grow within. In order to both have healthy food crops and sustain the environment for future generations, soil fertility must be maintained and promoted.

Hydroponic growers take soil out of the equation and grow their plants in mineral solutions to which they manually add microbes.

Donielle Nolan, George Mason University’s greenhouse coordinator, works with GMU’s office of sustainability to produce hydroponically grown vegetables for the university’s dining hall.

“Maybe it’s not exactly the same, but you can get really, really close to the same microbial communities that you would have in soil,” Nolan said. “For instance, in my hydroponic system I add to the water beneficial bacteria and beneficial fungi which not only hep me to compete with pests, but they also keep the plants healthier.”

Microbial communities in any setting are very complex and diverse making it difficult for scientists to assess the comparability of manmade microbial ecosystems to those in soil. Dr. Adam Diamond, an expert on food sustainability and political economics at American University, said some farmers and researchers believe bacterial communities in hydroponic settings are not comparable to soil. Diamond referenced his conversation with a farmer who stopped growing with hydroponic systems when he discovered research showing soil-less plants were less nutritive as a result of insufficient bacteria.

“They were growing hydroponics and they decided to stop because they found out that hydroponic vegetables had a lot less nutrients,” Diamond said.

Nolan said it is unfair to categorize hydroponic plants as less healthy than soil-based plants.

“If you have just like really sandy soil there could be very few microbes and very few nutrients in there,” Nolan said. “And, if you look at a really healthy hydroponic system there could be more microbes and the produce could end up being more nutritious.”

Not only are natural bacterial communities in soil difficult to study, hydroponic systems’ bacterial compositions vary from garden to garden. Some case studies show equal or greater nutritional value in hydroponics crops, while other studies show the opposite. In general, there has been little research on the topic.

Lack of research will remain an issue if hydroponics become less relevant to consumers. As consumer demand for organic food continues to rise, forbidding organic certification to hydroponic systems could decrease their relevance as a food production system.

“So, again, trying to make hydroponics not organic is not helping the situation,” Nolan said. “It’s not bringing it any further. It’s holding us back, for sure.”

The demand for organic food and increased desire to eat healthfully is the main reason for the rise in hydroponic farms. If the NOSB decides hydroponic plants cannot be labelled organic then consumers may reasonably believe hydroponics are not organic and are thus less healthy. When demand for a product decreases the supply of that product decreases in response.

Any benefits of hydroponic farming which could include driving innovation in search of more advanced techniques would be reduced, or lost. While nutrition benefits of hydroponics growing may be hard to analyze, hydroponic farmers say there is no debate when it comes to sustainability.

“Well first of all, sustainability in terms of, like, not just sustaining the earth and future generations but sustaining the amount of effort you put into it because hydroponics–the biggest benefit, I think, is that there’s no weed,” Nolan said.

A large reason consumers buy organic is because they want to avoid potentially harmful chemicals used in conventional agriculture to reduce pests and weeds. Nolan said the controlled environment in a hydroponic greenhouse allows for less herbicide and pesticide.

“And on an industrial scale, they don’t have the labor to get rid of those weeds, so what do they do?, they cover it in herbicide,” Nolan said.

The hydroponic farm Nolan runs at GMU is not certified organic, but they use no chemical pesticides or herbicides. However, if Nolan were to seek organic certification in the future the USDA might have a problem with something else besides chemicals. Hydroponics systems grow their plants in a water-mineral solution, but there are other growing media involved. Coconut husks, coconut cores and peat moss are some of the typical materials used in hydroponic pools.

Soil-based organic farmers take issue with these growing materials because they do not contain bacterial ecosystems as soil does. Container-grown plants also use these kinds of materials and, like hydroponics, do not have specific regulation sin the Organic Foods Production Act. All the same, there has not been little, if any, opposition against container-grown plants receiving organic certification.

“If you remove the microbes from the soil, all it is, is, clay and sand and like some organic material,” Nolan said. “And rock wool is, or especially coconut core; that’s still organic material, and if you’re adding microbes there’s like almost no difference–like, technically speaking–because you still have that life in the water and you still have that organic material that’s holding it together so, like, I don’t agree with that argument hat is’ any less good.”


According to the California Department of Food and Agriculture, more than a third of the nation’s vegetables and two thirds of its fruits and nuts are grown in California. The heavily farmed state has also been on the forefront of the organic and local food movement since the 1970s. As demand for organic foods has since risen, the number of  organic and hydroponic farms have both increased in California.

Dennis Nuxxoll, vice president of federal government affairs for the Western Growers Association, an association representing produce farmer sin western states including California, said any changes to organic labels will directly affect many of the association’s members. Nuxxoll voiced concern over the NOSB’s February discussion paper on hydroponics.

Nuxxoll said he does not see the problem with soil-less growing media like coconut husks and peat moss.

“I mean the the most fundamental line is, ‘Is it an organic substance or si it some sort of artificial synthetic additive?’ right,” Nuxxoll said. “I mean that’s the most fundamental thing, and now we’re dancing on the head of a pin because now we’re saying, ‘Yes, it’s an organic material, but it’s not active enough.'”

Although the majority of organic farmers are not hydroponic, disallowing hydroponics organic labels would reduce the organic food industry’s current size and future growth. As farmland becomes more sparse the needed increase in agriculture for greater populations will eventually plateau without alternative growing systems.

According to a 2015 study published by the Organic Trade Association, a business association representing U.S. and Canadian organic farmers, U.S. imports of organic foods far outrun exports, totaling nearly $1.3 million in 2014. As organic is the fastest growing marketing in food production so any regulations to this industry are considered heavily.

“In this country, the whole scheme of organic regulation is all about creating markets,” Diamond said. “And like, AMS [Agricultural Marketing Service] which oversees the organic program will not say organic is better for human health or the environment: ‘It’s what people want and we want to help farmers meet that demand.’ In many European countries, they have a very different approach and it’s that organic helps advance public policy goals like cleaner water, healthier soil, healthier food, better animal welfare.”

Markets are undoubtedly at stake in the debate of organic labels for hydroponics farms. But with little research on the nutrition of hydroponics plants, the debate is currently bound to the limits of profit-making motives and sticky legislative language.





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Isabella is a journalism major, francophile and health nut who loves dark chocolate, Otis Redding and Spanish cured ham. She loves traveling and dinner conversations that last until the wee hours of the morning.

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