Are Hydroponic Vegetables Healthy?
Hydroponics is a 17th-century creation becoming a 21st-century world-changing innovation. Despite its merits and benefits, there are still some negative rumours regarding how unhealthy or unnatural hydroponic vegetables can be.
Hydroponically grown vegetables and plants are completely safe for consumption. Hydroponics is as healthy as traditional cultivation. In fact, hydroponics uses less pesticides and less herbicides since hydroponically grown plants are raised in a safe and clean environment.
But where does the negative image of hydroponics originate from? Where is the scientific data showing the merits of hydroponically grown vegetables?
Why Is There Negativity Surrounding Hydroponics
The reason why there is negativity about hydroponics is that the latter is not certified as “organic” by the USDA. In the 1990s, the Organic Foods Production Act of 1990 (OFPA) was passed. It was to assess whether or not livestock or crops pass compliance to be certified as “Organic.” The aim of the law was to ensure and incentivize agricultural practices which are in harmony with nature by preventing the use of harmful chemicals and prevent soil deterioration.
The current USDA standards require that crops be grown in soil for it to be certified as “Organic.” Though there have been proposals to include hydroponics under the organic label, these have been met with strong opposition. Even when hydroponic farms that manage to comply with the standards and acquire certification, they are under fire from traditional agriculturalists who argue that their livelihoods are being undercut by certifying hydroponics under organic.
Due to the negative image of chemicals in agriculture and the lack of organic certification, hydroponics is often seen as the less natural and less organic hence less healthy method of agriculture.
Are Hydroponically Grown Vegetables Bad?
Hydroponically grown vegetables are perfectly safe for consumption and have the same nutritional value as those grown in the soil, if not better. It is a fact that hydroponically grown vegetables are placed in controlled conditions wherein they are free from pesticides, herbicides, and soil pollution.
Hydroponically grown plants might be healthier and safer for you
Studies show that there is a higher concentration of flavonoids (antioxidants) in medicinal plants. Another study shows that hydroponically grown basil is healthier than conventionally-grown basils. The antioxidant activities of both aqueous and lipid extracts were evaluated and it showed improved antioxidant activity with increased content of Vitamin C, Vitamin E, phenols, rosmarinic and lipoic acid. In simpler terms, they are healthier.
Another study using lettuce of the lollo rosso and red oak leaf variety as the subject. At the end of their storage, the lettuces were cut and it showed that there was increased Vitamin C content. At the end of the shelf-life, there were less lactic acid bacteria and coliforms in hydroponically-grown lettuce. It means that soilless systems can provide higher quality and microbiologically safer products for human consumption.
Nutritional Content
A further dive into the consolidated and in-depth study in the book Vegetables Importance of Quality Vegetables to Human Health further prove that hydroponically grown vegetables and fruits have higher nutritional value than their soil-grown counterparts. It showed that hydroponics produce plants with higher levels of Iron (Fe), Vitamin C, and other micro and macronutrients depending on the plants cultivated. The soilless plants also have higher concentration of antioxidants, substances which can prevent or slow the damage to cells caused by free-radicals. The higher nutritional value of hydroponic plants is suspected to be the effect of higher biomass accumulation allowed in hydroponics systems. These findings are corroborated by different scientific journals such as Acta Horticulturae, Postharvest Biology and Technology, and Pesq. Agropec. Trop., Goiânia, to name a few.
The general consensus of these studies is that the higher bioactive compounds in hydroponics is because of the controlled cultivation process inherent in hydroponics itself, creating the most ideal version of the plant. In conclusion, not only are hydroponically grown vegetables and fruits healthier but also safer.
Where Does Hydroponics Excel or Match Soil-Grown?
Hydroponically grown vegetables have been proven by scientific studies to have the same nutritional content, taste, and quality as soil-grown crops, if not better. Though some studies differ depending on the plant type, it can be concluded that there should at least be perfect parity between the two methods and the results they produce under normal circumstances.
As such, we can conclude that there should be no significant difference (or any difference at all!) in the visual or sensory qualities between soil hydroponically grown plants to soil-grown plants. The greatest difference lies in the method in which they are raised.
Hydroponic vs Traditional Grown Lettuce and Vegetables
Here let’s have a quick tour of several studies (all reported in the sources) regarding the observed differences (if any) between hydroponic and traditionally grown vegetables (lettuced included).
Spoiler Alert: Hydroponic is better in a few aspects!
Taste, Visual Quality, Texture, Odor
No “significant difference with respect to visual quality, texture, odor, taste or taste character“ between sample lettuces sourced from hydroponics vs conventional farms.
This was proved by a study by the Department of Nutrition in the University of Nevada wherein they sampled lettuces grown “traditionally” and hydroponically. The final results revealed that there was no noticeable visual or sensory difference between the two.
Tomatoes also show no significant difference between these four qualities. Tomatoes grown soilless versus those grown in soil looked and tasted the same.
It must be noted that these qualities are highly dependent on the genetics, the species, and external environment of the plant rather than the method used. This applies to both soilless and soil-based agriculture.
Less Pesticides and Herbicides
There is less pesticides and herbicides used in hydroponics because most hydroponically-grown plants are raised in a controlled environment hence factors such as pests and unwanted plants are no longer a problem.
Hydroponic farms can be built indoors which drastically reduces the exposure of the plants to these unwanted factors. Since the plants are grown in water that is controlled and regulated, the plants are free from soil diseases, pollutants, or plants which may compete in nutrient uptake.
As such, hydroponics create a natural form of pest-control by simply growing indoors. This means healthier and safer plants for producers and consumers alike due to the reduced presence or complete absence of pesticides and herbicides in the plants.
Faster Growing, Better Yielding
Apart from the possibly higher nutritional values and beneficial antioxidants, hydroponics may produce plants with less water, less time, and less space.
In the same study cited above, it was noted that a longer growing period was needed to make the plant in the soil grow to full maturity (102 days) compared to soilless growing (63 days). Scientific studies corroborate this fact that hydroponics methods cultivate plants faster, bigger, and cleaner.
There is much greater yield because of this since simple arithmetic applies. The more you can grow in less time and less effort, the better. A study comparing the average marketable yield showed a 20% increase in hydroponically growing lettuce. For strawberries, the yield per plant was 10% higher.
Less Water
Hydroponics uses 10x less water than soil-based farming because the water does not drain from the soil, according to the National Park Service. In hydroponics, the nutrient-rich water is recirculated from a reservoir to the grow bed and directly to the roots of the plant.
Why Hydroponics is Organic
Agriculture itself is unnatural. The mere fact that humans create the best possible conditions for the growth and reproduction of plants is already an unnatural process devoid from the true intent of nature. This logic applies to both soil and soilless agriculture.
What hydroponics does is the breaking down and simplification of the essentials of what a plant needs – Oxygen, Carbon Dioxide, nutrients, water and sunlight. What was only taken out of the equation was the soil which used to be the vessel of the nutrients. Water took over that role.
I’d argue that hydroponics is organic and more true to the ideal set out by the Organic Food Act of 1990 because it does nothing to the soil. Preservation of the soil and the harmony with the ecosystem is one of hydroponics’ greatest boon as it uses less water and requires less of everything to improve the growth of the plants. It is the natural evolution of agriculture.
There are other forms of hydroponics that further build on this ideal such aquaponics – the marriage between aquaculture and agriculture. The nutrient-rich organic matter released by the fish is absorbed and filtered by the plants and recirculated into the system, producing both fish and plant products. It can’t get any more organic than that.
Takeaways
- Hydroponically grown vegetables are completely safe and fit for human consumption.
- They are not dangerous and are as nutritious (if not more) than their traditionally-grown counterparts.
- Hydroponically grown vegetables are more “organic” in the sense that they use less water, less space, less herbicides/pesticides, and do not deteriorate the soil.
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SOURCES
“Are Hydroponic Vegetables as Nutritious as Those Grown in Soil?” by Sophie Egan in Well Blog New York Times
“Can Hydroponics be organic? And does it really matter?” by Preeti Shanker in Protected Cropping Australia
“Comparative performance of tomato on soilless vs in-soil production systems” by Maboko et al in Acta Horticulturae 843(843)
“Comparison between Growing Plants in Hydroponic System and Soil Based System” by Gashgari et al in The 4th World Congress on Mechanical, Chemical, and Material Engineering
“Comparison between Hydroponically and Conventionally and Organically Grown Lettuces for Taste, Odor, Visual Quality and Texture: A Pilot Study” by Murphy et al in Food and Nutrition Sciences 02(02)
“Hydroponic Production Systems: Impact on Nutritional Status and Bioactive Compounds of Fresh Vegetables” by Alfredo Aires in IntechOpen
“Hydroponic Vegetable Production” by Merle Jensen and W.L. Collins in Horticultural Reviews 7:483 – 558
“Hydroponics as an advanced technique for vegetable production: An overview” by Sharma et al in Journal of Soil and Water Conservation 17(4):364-371
“Hydroponics: A Better Way to Grow Food” by n/a in National Park Service
“Hydroponics: The End of Organic?” by Sarah Morath in NR&E Summer 2018
“Levels of antioxidants and nutraceuticals in basil grown in hydroponics and soil” by Sgherri in Food Chemistry 123(2)
“Organic Production/Organic Food: Information Access Tools” by Mary Gold in USDA National Agricultural Library
“Sensory quality, bioactive constituents and microbiological quality of green and red fresh-cut lettuces (Lactuca sativa L.) are influenced by soil and soilless agricultural production systems” by Selma et al in Postharvest Biology and Technology 63(1)
“The Fight for Organic: Hydroponic Certification Under Fire” by n/a in National Agricultural Law Center
“Want Fresh Produce? Leave Dirt Behind” By Glenn Collins in The New York Times
“Yield and quality of tomato grown in a hydroponic system, with different planting densities and number of bunches per plant” by Cardoso et al in Pesq. Agropec. Trop., Goiânia (48)4