nutritional quality of hydroponics vs. soil grown veggies and fruit

hydroponic1

vegetable-raised-bedsI recently received a question on my Facebook page asking this question:

“Can you tell me if there is a difference in trace elements found in soil grown foods as opposed to hydroponically grown foods?”

Great question! Yes there is a lot of promotion of hydroponically being better for the environment (which it is), but nutritionally, what’s the deal??? We generally don’t hear or see too much publicity if anything in that department…

After doing a bit of research into the issue of hydroponic nutritional value vs. soil-grown nutritional value, it has simply reaffirmed by firm belief in “eat colour – you’ve got all your bases covered then.”

Here’s my response:

Nutrients/trace elements from the soil do contribute to the nutritional make up of soil grown fruits and vegetables. In the case of hydroponically grown foods, in theory they do not have access to these trace elements – they rely on water to grow. However in order to combat this, hydroponic growers supplement the water supply with trace elements and compounds.
If done correctly, hydroponics can have the same nutritional benefit, or even more (if the water supply is “spiked” so to speak). However if done incorrectly, or not done at all, this may affect the nutritional properties of the edible plant negatively (however without adequate sunlight and access to nutrients, the plant won’t be able to produce much edible flesh, it at all).
Soil grown vegetables and fruit need nutrients added to the soil as well – so the same issues with hydroponics could happen with soil if done incorrectly.

The one major difference with soil and hydroponics is that you can grow organic produce in soil. Hydroponics, by nature are not organic – they require added nutrients to make them grown.

The disadvantages of hydroponics are:
1)The hydroponic conditions (presence of fertilizer and high humidity) create an environment that stimulates salmonella growth – therefore must be carefully controlled;
2)Prone to pathogenic attacks including damp-off due to Verticillium wilt caused by the high moisture levels associated with hydroponics (but this is also associated with overwatering of soil based plants – so no difference there);
3)From a practical perspective, many hydroponic plants require different fertilizers and containment system – so it can be quite complex.

On the upside, the benefits are:
1)No soil is needed (you could do it anywhere – on top of an apartment building, in an arid environment etc. – just as long as you have a good water supply);
2)The water stays in the system and can be reused- thus, lower water costs;
3)It is possible to control the nutrition levels in their entirety- thus, lower nutrition costs – i.e. by constantly maintaining a controlled nutrient water supply (soil is prone to fluctuations – so it’s nutrient needs constantly change);
4)Environmentally friendly as nutrition pollution is not released into the environment because of the controlled system;
5)Stable and high yields;
6)Pests and diseases are easier to get rid of than in soil because of the container’s mobility.

A study in 2000, published in the “Practical Hydroponics & Greenhouses” compared hydroponics to conventionally produced vegetables and found that hydroponic produce can be superior in nutrition and taste – but this is dependent on the nutrient content of the hydroponic solutions. Stronger nutrient solutions can ensure a better product than conventionally produced vegetables.

However it must be remembered that hydroponics and soil-plants both require proper control.

Vegetables and fruit should always be a staple in anyone’s healthy diet – whether hydroponically or soil grown. They are not completely devoid of nutritional benefit – you won’t be consuming empty calories :-)! Regardless of how it is grown, it is ALWAYS going to be superior to a chocolate bar or serve of deep-fried something.

As long as you are getting plenty of colourful fruit and veggie variety in diet (whether hydroponic or soil grown) you’re on a winning streak.

Now grab a carrot and enjoy life :-).

14 comments

  1. Thank you for this interesting & helpful article. Love the conclusion that it’s more important to eat veggies & fruits, eating variety of colors, than worry too much about hydroponics vs soil grown produce. Discovered you via googling on this very topic. Keep up the good work!

    • Thanks George Kao :-).
      I think it is easy for consumers to get bogged down on the small details not the larger picture. And at the end of the day having veggies in your diet is way better than not. Hope you find more info on here that you can use :-).

  2. Dear Anneline,
    Do you know of any peer-reviewed articles that touch upon the topic discussed above? Or any universities/companies undertaking research at the moment?

    Thanks,

    Céline

    • Hi Celine,
      Thank you for your questions.
      Papers in this space are dated, and not as common as say – dietary intake affects on oxidative stress etc…
      However here are a couple of references that I used that you may find useful:
      Hydroponics methodology is essentially the same – nutritional output is affected by the available nutritional supply (i.e. the nutrient content of the solution): Adams, P. 1993. CROP NUTRITION IN HYDROPONICS. Acta Hort. (ISHS) 323:289-306;
      Stamatakis, A., Papadantonakis, N., Savvas, D., Lydakis-Simantiris, N. and Kefalas, P. 2003. EFFECTS OF SILICON AND SALINITY ON FRUIT YIELD AND QUALITY OF TOMATO GROWN HYDROPONICALLY. Acta Hort. 609:141-147;
      Premuzic,Z., Bargiela, M., Garcia, A., Rendina, A. and Iorio, A. 1998.Calcium, Iron, Potassium, Phosphorus, and Vitamin C Content of Organic and Hydroponic Tomatoes. HortScience 33(2): 255-257;
      Rouphael, Y. and Colla, G. 2005. Growth, yield, fruit quality and nutrient uptake of hydroponically cultivated zucchini squash as affected by irrigation systems and growing seasons. Scientia Horticulturae, 105(2): 177-195.

      Whilst I am not personally aware of universities undertaking specific research relating to this topic, I am sure there would be…My suggestion is to contact the researchers in the articles listed above directly – clearly they’re working in this space, or if they’ve moved on, they’d be able to direct you in the right way…

      Kind regards,
      Anneline

  3. Good points. I grow my own hydroponic lettuce and in addition to adding regular grow fertilizer I add sea water derived trace minerals into the water. My lettuce tastes great and although I do not know where to get it laboratory-nutritionally tested I am fairly certain it has good nutritional content plus I typically never have to spray any nasty chemicals on my food.

  4. Hello any body Know about detail according to “Which Nutritional Value of crop is change due to aeroponic system with respect to Soil grown farming system” ??

  5. Soil depletion in the farmland has led to an ever decreasing nutritional value of farm grown crops. Between 1950 and 2000 decreases of 20 to 30 percent in some categories are noted. A professionally grown hydroponic vegetable will have higher values as micronutrients are easier and more cost effectively added to the plants as they are grown.

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