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Article published in Dropline.biz on December 19, 2005 Hydroponics—“Growing Plants in Water” By Sarah D. Goldstein (co-authored by Dino M. Zaffina) Many horticulturists over the years have claimed to be the inventor of hydroponics. Unfortunately, for these individuals, history has revealed that hydroponics has been around as far back as 600 B.C. in the Hanging Gardens of Babylon. Later, in the 11th century, the Aztecs used hydroponics for their Floating Gardens. Fast forward to the mid-19th Century, to a time when the German plant physiologists Sach and Knop grew plants in simple solutions of inorganic salts. In 1929, Professor Gericke of the University of California, Davis demonstrated that plants could be grown soil-free all the way to maturity, growing tomato plants in water to a quite remarkable size. By analogy with the ancient Greek term for agriculture, geoponics, the science of cultivating the earth, Gericke coined the name “hydroponics” for the culture of plants in water (from the Greek hydros, water, and ponos, labour). (Wikipedia). A hydroponics garden is low maintenance and efficient. Goldman, during childhood, grew plants and many of the vegetables for his family’s consumption, using this system. Goldman lived in apartments and there was a lack of space and soil. These earlier experiences proved to be Goldman’s future occupation. Many people confuse hydroponics with the recent fad of “organically grown” plants and vegetables. During our interview with David Goldman, we asked if he could explain the difference between the two processes. Goldman replied, “I will go one step further.” He explained, “I will provide you with The Debate on Organics and Hydroponics.”
There is a huge debate about the value of “organic” fertilizers and methods. Currently accepted organic fertilizer components are dependent upon organisms in the soil to convert the “organic” materials into a useable form for plants. At Culinary Farms, we provide the minerals required for plant growth directly, completely eliminating the need for soil and soil-organisms. The result is much higher growth rates, yields, and even crop quality than organic methods can achieve. This is not what some people want to hear, but it is the simple scientific truth - and practically all scientists and educators in the fields of agriculture and chemistry know it and will be the first to agree. In fact, the kinds of materials that are permitted for use under “organic” regulations are not of sufficient purity to be used for hydroponic culture. At Culinary Farms, we use only the most refined and pure ingredients to blend our hydroponic fertilizers, including food-grade and pharmaceutical-grade minerals. “Organic” regulations do not permit purified or refined ingredients to be used. All “organic” fertilizer ingredients must be in their natural, unrefined form. The result can be detrimental levels of impurities and toxins plus very poor solubility. “Organic” is a matter of bureaucratic definitions, not science. Organic is a method of farming, not a definition of the produce itself. There’s no such thing as “organic produce,” there’s only “organically grown produce.” With this in mind, it’s important to recognize the reasons that “organically” grown produce is gaining such popularity. Consumers want to buy produce that is not tainted with hazardous chemicals or poisons. There is an increasing public demand for methods which are gentle on our delicate planet and which don’t harm the soil, water, or ecosystems. Hydroponic farming methods fit properly into this system of values if used appropriately. Hydroponic protects soil because it doesn’t use soil. Far less water is required for hydroponic culture and consequently more food can be cultivated with less water. The fertilizers we use at Culinary Farms are ultra-pure and leave no residue in the cultivated fruits and vegetables. Since hydroponic technologies are more efficient than soil methods, more people can be fed with less area and ecological impact. Also, it has been stated that it would not be possible to organically grow enough vegetables for everyone on the planet to eat because there simply is not enough compost and manure, etc. to do so.
If a plant is grown without soil and with a complete nutrient solution-that’s hydroponics! It can be as simple as plants growing in sand, gravel or rockwool with a nutrient drip, or as complex as a complete water culture system such as NFT (Nutrient Film Technique, the system used by Culinary Farms) or aeroponics.
We would think that this is an easy question to answer, but it isn’t. In the United States there are numerous different definitions of “organic,” many of which differ significantly. Each state has its own regulations for labeling produce as “organic.” Additionally, there are 36 nongovernmental organizations that can certify produce as organic. For example, California growers who wish to sell their produce as “organic” must register with the California Department of Food and Agriculture and pass their inspection. However, California grower’s can also obtain certification through the California Certified Organic Farmers (“CCOF”), which actually has higher standards for organic than the state has. The CCOF certification is optional, but produce with California state registration and CCOF certification may be offered for sale within the state as “certified organic.” If the grower chooses not to seek CCOF certification, the produce can be offered for sale in California as “organic,” but not “certified organic.” Any produce grown outside of the United States can be sold as “certified organic” in the country if one of the 36 nongovernmental organizations certifies it. In fact, produce from any state can be granted certification from one of the nongovernmental organizations, even if it does not meet the organic standards for the state in which it is being sold. Pretty confusing! What this all means is that the “organic” label is a matter of bureaucratic definitions that can vary from state-to-state, and country-to-country. In order to bring some kind of standard into play, the U.S. Department of Agriculture (“USDA”), along with state government regulators, nongovernmental certifiers, consumers, industry interest groups, food processors and various special interest groups is writing a federally mandated set of “organic” standards. No state will be able to apply more stringent standards than those of the federal. The basic objectives of organic” practices include the following:
Soilless hydroponic cultivation moderates nutrient supply by the more exact measurements of soluble nutrient formulations, mixed to meet the optimum requirements of each plant species and growth phase. Many consumers select “organic” produce, believing that this is the only way to be assured of pesticide-free non-hazardous food. While “organic” farming methods do produce crops generally superior to and safer than those grown by agribusiness practices, modem hydroponic techniques can put forth equally safe food that in many cases offers advances in nutrition and taste over their soil-grown “organic” counterparts. But to the consumer, it’s the label that counts, so an increasing number of growers throughout the United States are struggling to get organic certification in anyway, shape, or form. Meanwhile, this whole situation poses an enormous dilemma to hydroponic growers who also want organic recognition for their produce. The primary problem for organic hydroponic growers is in the formulation of the soilless nutrient solution. Organic nutrient regulations prohibit the use of many mineral salts and highly refined substances, including food and pharmaceutical grade ingredients that are extremely important for successful hydroponic nutrient formulation. Only unrefined minerals can be used on “organic” crops and these often don’t dissolve well or contain quantities of impurities, some of which are even relatively toxic, but “natural and therefore okay,” according to organic standards. For example, mined phosphate may contain excessive amounts of fluoride, good for teeth in very small quantities, but harmful to humans in excess. Mined phosphate also can contain small amounts of radioactive elements such as radium, which releases radon, also not good for human health. Chlorides, too, are permitted for organic cultivation, but though they are naturally mined, they can be bad for both plants and soil, especially if used in excess. Some soils used by organic farmers contain such toxic elements as selenium, which can accumulate in the plant tissues and produce. Amazing, isn’t it? When refined, any impurities or toxicities such as those listed above are removed, but refined minerals make for non-organic produce. Blood meal, bone meal, fish meal and manures pose almost no potential safety hazards, but they don’t dissolve very well; they must be broken down through microbial action in the soil and therefore don’t work well in hydroponic applications. There is also a problem that sometimes arises when using manures. The Western Fertilizer Handbook, an important guide for American farmers, points out that many gastrointestinal illnesses can he traced back to manures used on organically grown crops. In the summer of 1995, a serious outbreak of salmonella poisoning resulted from an organic cantaloupe crop growing in soil fertilized with fresh chicken manure. The rinds of the melons had become contaminated and the bacteria caused serious intestinal illness for many consumers. Another point to consider is that many farm animals today are injected with antibiotics and hormones. These substances pass through their bodies and end up in the manure that many farmers use to fertilize their crops with and also to make compost. These substances are in turn taken up by the crop and imbed themselves in the plants’ tissues. So, even though the produce was grown organically, it will still contain the antibiotics and hormones. Yet, another point that can be made is that strict vegetarians or animal rights activists may be offended by the use of blood, bone, horn, hoof, and feather meals to grow their food, but these are primary nutrient sources for organic farmers. As you can see, this issue is very complex and there are many points of view. Essentially though, “organic” fanning is part philosophy and part methodology, but unfortunately, defined bureaucratically.
In 1994, a test was commissioned by an investment group to determine the vitamin and mineral content of hydroponically grown crops in comparison to soil grown crops, both organic and non-organic. Plant Research Technologies Laboratory in San Jose, California, analyzed tomatoes and sweet peppers. The hydroponic produce showed a significant increase in vitamins and minerals beneficial to human health over the soil-grown produce. Not only were they of higher nutritional value, the flavor was reported to be outstanding. The hydroponic crops were further analyzed to search for chemicals on the EPA’s “priority pollutant list,” of which, none were found. Although hydroponically grown produce, while usually free of pesticide and other chemical hazards, does not generally meet the rather narrow definitions of “organic”; it can offer superior flavor, nutrition, appearance, freshness and shelf life. Many small hydroponic growers are recognizing these market trends and cashing in on the huge demand for higher quality produce. Small growers find that gourmet restaurants and local markets are delighted to have access to superior quality produce, whether organically or hydroponically grown. Since “organic” is pretty much out of the question, an increasing number of hydroponic growers are promoting their produce as “pesticide-free.” This gives the consumer the reassurance that their fruits and vegetables have been grown following the most important principal of “organically” grown produce. One consequence of this dichotomy is that the term “organic agriculture” is declining in favor of the term “sustainable agriculture,” which applies to both organic and hydroponic cultivation. Though many organic growers look down on hydroponic technology, the superior quality and freshness of locally grown hydroponic produce is in fact gaining market acceptance. Hydroponic plants are usually grown in a relatively sterile environment, and often with precise controls, from artificial lighting to extend growing seasons to exotic computer systems that enable the grower to actually tailor the environment to the crop wherein hydroponics becomes just one part of the entire system. In this type of setup, labor is reduced, yet plant growth rates, yields and quality increase. Many attempts have been made to create the perfect organic-hydroponic nutrient, but so far nothing matches the purified mineral salts used in formulating hydroponic nutrient solutions. We note that the European Economic Community (“EEC”) has established the category of “mineral organic” for foods grown with the required mineral nutrients to supplement an organic base of nitrogen. We previously touched on the fact that United States agricultural regulations are currently set and applied at the state level but practically all states prohibit the use of refined ingredients to cultivate “organic” crops; only mined minerals can be used. Surprisingly, this precludes organic growers from using pharmaceutical or food grade ingredients to formulate fertilizers. This could be a safety risk, but at least mined minerals will break down in the soil. Hydroponic growers, on the other hand, must use refined minerals because mined minerals dissolve poorly in solutions. As a consequence, it is not currently practical to formulate a top-quality “organic” fertilizer that will work well for hydroponic crop production, and meet standards. Federal regulators in the U.S. Department of Agriculture will soon complete a review of the standards for defining “organic.” There is some possibility that the USDA may eventually consider the European standards, opening the door for organic growers to use purified mineral nutrients and hydroponic growers to cultivate organically certified produce. It is not surprising that European regulations favor policies that promote the cultivation of produce with superior quality and flavor. Generally, European consumers are accustomed to higher quality foods and will not purchase flavorless produce. The myth that only certified organically grown produce is of good quality, nutrition, and flavor has been clearly dispelled by the many successes of hydroponic producers worldwide, but remains predominant in public perception. This trend will most likely continue; the only question is whether the United States will be a leader, or a follower. Author’s note: I don’t wish to leave readers with the impression that there’s anything wrong with organic, or that hydroponic produce is always better. It can go either way depending upon the skill and ethics of the farmer. The main issue is for growers and consumers to understand that “organic” is a matter of definitions. Sometimes the organic produce is the best tasting and most nutritious available in the marketplace; other times the hydroponic produce is better. In the final analysis, both hydroponic and organic methods are excellent. There you have it, The Debate on Organics and Hydroponics. For more expert information contact David Goldman by e-mail at dgoldman@bghydro.com or visit the companies’ websites at www.bghydro.com and www.livinglettuce.com. Hydroponics is useful to us in two main ways. First, it provides a more controlled environment for plant growth than soil thereby removing many unknowns from experiments. Second, many plant species produce more in less time and sometimes of higher quality, which under certain economic and environmental conditions, makes hydroponics growing more profitable to the farmer. With hydroponics there are no soil-borne diseases, weeds to pull, or soil to till, and plants can be placed very close to one another. This allows a large amount of food to be produced in a small amount of space. Hydroponics is also very water-efficient as it uses containers or closed loop systems causing water recirculation, and therefore requires only a small fraction of the water used in traditional farming. (Wikipedia). The simplest method of hydroponics can be achieved by placing a plant in a container (pot or bag) of growing medium, and the container stands in a tray of nutrient solution. The medium generally has large air spaces, allowing ample oxygen to the roots, while capillary action delivers water and nutrients to the roots. A variety of materials can be used for the medium: vermiculite, perlite, clay granules, rockwool, gravel. Some newer media that are becoming popular are coir fibre, and cocoa been shells. This needs the least maintenance of all hydroponic methods, requiring only topup and occasional replacement of the nutrient solution. This keeps the medium regularly flushed with nutrient and air. It is important in passive hydroponics to wash out the system from time to time to remove salt build up. This may be checked with a PPM (Part Per Million) meter, a good average reading would be about 1,500 PPM. Lettuce is happy with about 800 PPM and tomatoes to 3,000 PPM, but both will grow reasonably well on 1,500 PPM. It is important to keep the pH reading at about 6.3 to enable nutrient uptake. Data are available for the optimum settings for most plants. This is commonly employed for large display plants in public buildings: in Europe a system using small clay granules is marketed for growing houseplants. (Wikipedia). Although hydroponics is useful and an expanding area of agriculture, it is not without problems. On large scale commercial operations computers can be used to help control the different factors, making hydroponics more complex and thus more expensive. However, the added benefit of computer controlled growing environments is that manual intervention is kept to a minimum. There are experimental computer systems which allow every aspect of the growing environment to be monitored remotely, via a network. Luckily, hydroponics is not nearly as difficult when done on a small scale. Hydroponic systems may be as complicated or as simple as the gardener’s abilities and needs dictate. Often more advanced systems will produce more abundant or higher quality crops. However even the simplest hydroponic system can yield incredible results when compared to their soil counterparts. (Wikipedia). _________________________________________________________________________________________________________________________________________ |
Articles Written or Co-Authored by Dino M. Zaffina |
© 2022 Dino M. Zaffina. All rights reserved.
Hydroponics is the process of growing plants without soil. The plants are grown in water to which nutrients have been added.
There are now hydroponics home gardens and commercial cropping operations in the United States and many other countries. Under hydroponics, plants can be grown closer together than in the field, thereby increasing yields, and multiple cropping (the growing of several crops in the same tank) can be practiced. In addition to conserving space, hydroponics almost eliminates weed and pest problems. The cost of equipment is high and personnel must be trained. Although hydroponics is possible for most plant species, a limiting factor is the amount of physical support required. Usually the plants are held upright by wire supports or are rooted in a sterile medium, e.g., pure sand or gravel. The nutrient solutions must supply, in optimum concentrations and in correct balance, the elements, such as nitrogen, phosphorus, potassium, and other essential nutrients normally found in soil. Other names for hydroponics are soilless gardening, soilless culture, chemiculture, and water gardening.
David Goldman, President of BetterGrow Hydro and Living Lettuce Farms (
A new niche is developing for small hydroponic growers, family farms, and even urban farms in areas that have traditionally been served by large corporate farms far away. The simple truth is that top quality organically raised produce can only be grown under fairly ideal conditions and only seasonally in most parts of the United States. This results in produce that is expensive and frequency unavailable or shipped from afar, causing quality to suffer. In the “organic” model, good soil is enriched with compost, blood meal, bone meal, manures, and a host of other natural amendments. These components break down slowly in the soil at a rate in harmony with the plants’ growth; a microbiological process is required to make the nutrients available to the plants. These microbes include many organisms that are all in a symbiotic embrace with the environment and the plants. When done skillfully in the right environment with the right crop, this is nature and farming at its finest. But it differs sharply from the hydroponic model, where microorganisms are unnecessary for the plants to absorb the prepared nutrients. The nutrient absorption rate of a hydroponically grown plant is generally much faster than that of a soil grown plant, since in hydroponics, nutrients are instantly soluble and available, as is essential oxygen.