1 HISTORY OF HYDROPONICS - O MUNDO DA HIDROPONIAhydor.eng.br/HISTORIA/C1-I.pdf · History of...

History of Hydroponics

1

HISTORY OF HYDROPONICS 1.1 - INTRODUCTION Growing plants without soil, an agricultural technology today known as Hydroponics, was developed along the years from laboratory experiments carried out by scientists de-voted to the identification of which substances the plants ware composed of, as well as which of them make plants grow and develop.

This technology, today accepted by many researchers as a science, was developed too from laboratory researches on plant nutrition.

The known documents we have show us that those researches begun in the years 1600. However, since long time plants have been grown without soil. This really hap-pens, since life begun in water on our planet. We can say that the development of plants hydroponically in the water of the seas, rivers and lakes, date from the beginning of life on the planet Earth. That’s why we can say that hydroponic cultures, preceded soil cultures. The history of hydroponics is like a tree with deep roots. With its trunk firmly anc-hored in soil, showing its exuberant top, flourishing, fruiting and reproducing, hides howev-er the most recondite places where it looks for its food. The roots of that history go from the formation of the seas, rivers and lakes, to the ancient China. From Arabia to the Greece of Aristotle. From Babylon to the United States of America. From ancient Egypt to the Aztec people. From Leonardo da Vinci to Joseph Priestley. At long last, from Ancient Age, to Modern Age, and from here to actual days. To our regret, our history extends from the First to the Second World Wars. How-ever, it runs from the cold Russia to North Africa, from our Planet to the outer space, and from there, soon, to other Planets. As we told before, being an agricultural technology, hydroponics was born from the studies on plant nutrition, and we understand that everything and all those people that had any relationship with those studies are an integral part of its history. We also believe that the researches and discoveries within inorganic and organic

1


chemistry which happened within these last centuries are intimately related to hydropon-ics. It is not our intention to rewrite here the history of agriculture or the history of che-mistry, but it is our understanding that it is a part of the knowledge of any hidroponicist, to know how it begun and where from came the technology he handles or he has the preten-tion to use someday. We are aware that sometimes we will be somehow out of the storyline we pretend to transmit to our readers. But it is our intention to disrupt some myths, or to transmit in a better way some his-torical facts not always widely reported, and with this, to set sparse knowledge. We still believe that once knowing the historical facts we report here, the hydropo-nicists will become more conscious about the origins of the hydroponics technology, and so adding more value to what he is using or pretends to use some day. At the same time, our reader will have in hands several informations that will be like weapons for him to defend this technology, still very fought for merely commercial reasons or by other ones arising in the ignorance of real facts that were the basis for its origin. We will try to illustrate our words, interweaving them with images we collected dur-ing these last years. We recognize here that frequently we will be extremely repetitive in relating some facts, but we recognize too that repetition is the best way for one to memorize things in a way they will never more be forgotten. 1.2 – THE PAST During the era Before Christ, history tells us that the Arabs grew melons on the dry and sandy riverbeds, watering the plants with solutions of composted animal excreta, and the same process was used in India to grow cucumbers, watermelons and other greens. Rice cultures in China, for millennia, are carried in water, and this procedure was detailed for us in the diaries of the well known Venetian, Marco Polo. Another very old registry about soilless cultures refers to the Suspended Gardens of Babylon, which are one the Seven Wonders of the Ancient World. However we make some restrictions about this registry, because until the present date, we cannot affirm that those gardens existed.

With the permission of our reader we will explain the reasons for such doubt. It is proven, be it by historical facts, be it in various parts of the Bible, and even by the ruins that exist until today, that Babylon existed at the east margin of Euphrates River, about 50 Km at the South of Bagdad, in actual Iraq. The most ancient documents, dated 3000 years BC, tell us about “Babilon”, which flourished under the reign of Hamurabi (1792 to 1750 B.C.).

2


3

Fig. 1.1 Marco Polo (1254 to 1324) “Babilon” was captured by the Hittites in 1595 B.C., who kept complete control over it, during the Cassita dynasty, between 1590 and 1150 B.C. and during that time the city name was changed to Babylon, then becoming the central capital, and later, the religious center too.

Fig. 1.2 Suspended Gardens of Babylon (Watercolor painting showing how it could have been)

Only in the reign of Nabupolassar (625 to 605 B.C.), of the Neo-Babilonian dynasty, the Mesopotamia reached its larger glorious exponent. It is credited the building of the Suspended Gardens to the son of Nabupolassar, Nabucodonosor II, who reigned between 604 and 562 B.C. Stories tell us that the gar-dens were built to please Amitys, the wife or a concubine of the king, who “was brought to


the city, from the mountains region, and felt bored in those sandy plains”. Nabucodonosor died in 562 B.C. before finishing the gardens, which were con-cluded only in 500 B.C.. It is curious that all the historical facts of this time are registered on clay plaques which were found during archaeological excavations, but no one talks about existence of the suspended gardens, though they describe in detail the city and the royal palace, de-pendences of government agencies, trade centers, and the walls surrounding the city. Still more curious, is that historians cited the gardens, as the coverage of the royal palace, and this should be cited in the plaques found. All we have are facts narrated by the Greek historians Diodorus Siculos, Berossus, Strabo, e Philo of Bysantium. Diodorus Siculos said: “The entrance of the gardens is inclined, as a hill side, and the various parts of the structure rise up ones over the others, layer after layer. On all this, the earth was heaped up and trees of all species were planted, which by its size and beauty, afforded charm to those who watched them. The watering machines lifted up the water in great abundance from the river, though these could not be seen”. Another description says – “The garden is square and each side measures four "plethra" (1 plethra ≈ 100 feet ≈ 30 meters) long. It consists of arched vaults supported on foundation blocks more or less cubical shaped. The top terraces which form the cover are accessed via a ladder". “The suspended gardens have plants cultivated over soil level, and the roots of the trees are embedded in an upper terrace, but not in soil. The entire assembly is supported by stone columns”. “Streams of water emerging from elevated sources flow on inclined channels. These waters irrigate the whole garden saturating the roots of the plants, keeping all the area wet. Thus, the grass is permanently green and the leaves of the trees grow firmly attached to flexible branches”. “This is a royal deluxe artwork, and the most shocking detail is that the work of culti-vation is over de heads of the spectators”.

Born in Agirium in Sicily, Diodorus Siculos, also known Siculos, The Sicilian, came to Rome about 50 B.C., where he wrote his “Bibliotheca Historica”, a world history com-posed of forty volumes.

Only the volumes from one to five, which talk about ancient history, and the vo-lumes eleven to twenty, which cover the years 480 to 301 B.C., survived. His work is littered with inaccuracies that go from dates to entire epochs, and is full of fictions with novelistic nature. Before World War First, German archaeologists dug the areas at the North of the ruins where there was the Etermenaki which many people believed to be the Babel Tower. At the Northwest of the city they found the ruins of palaces and fortifications and quite near, other ruins very similar to what was described as being the gardens.

4


Modern historians use the argument that when the soldiers of Alexander the Great reached the Mesopotamia and saw Babylon, they became impressed, and once back, they told many stories about the gardens with its palm trees, the Babel Tower, the royal palace and the Zigurats. But only during the course of the 20th Century, some mysteries around the Sus-pended Gardens became being revealed. Archeologists continue his fight in getting evi-dences, trying to reach to a final conclusion about such gardens, how they looked as, and how was their irrigation system. The most recent archaeological discoveries, located the foundations of the Royal Palace, the buildings with vaults, endowed with very thick walls, and an irrigation well. From these findings, they made reconstruction drawings of the city, as well as draw-ings of what could be a Suspended Garden. The Greek historian Strabo asserted that the gardens were located at the riverside. But the archaeological findings, place the gardens some hundred meters far from the Euphrates River, and this leaves us many doubts.

Fig. 1.3 Babylon – Rebuilding drawing according to archaeological excavations However, other recent excavations show solid walls about 25 meters thick near the sandbanks of the river, that could have been the form of steps, and these could be the beds of the Suspended Gardens, this confirming the reports of the Greek historians. The irrigation system of the gardens has been described with details by Berossus, a Babylonian Priest who lived around 200 B.C.. He described the gardens as:

5

“A square of bricks with about 120 meters side, and 23 meters high. The irrigation of the flowers and trees, was carried with water from Euphrates River, and was elevated


from it to the gardens by an endless thread system (Archimedes screw) permanently dri-ven by slaves who would take turns.

Fig. 1.4 Suspended Gardens of Babylon– Rebuilding drawing according to archaeological excavations

“This water was sufficient to form small but high artificial waterfalls that made the gardens still more beautiful. In the water channels, there were beautiful plants that were not planted in soil, but even so were exuberant and always green, and some of them were edible”. The archaeologist Robert Koldeway, who in 1899 discovered the irrigation well near the southern palace, concluded that the water was elevated from such well to the highest part of the gardens with a bucket chain pump. Koldeway observed too that various sustaining columns of the probable gardens were hollow, and he deduced that on the terraces they sustained, the trees were planted in such a way that their roots penetrated said columns, which were filled with soil. On the other side, the cited Greek historians say that the irrigation water came from the mountains, driven by channels lined with stones.

As we can see, everything is a series of doubts and suppositions.

However from these historical reports we can reach some conclusions. The methods used in those supposed Suspended Gardens, as they were described by the historians that never saw them, were well known at the epoch of Nabucodonosor between the years 500 and 600 B.C., or at least at the epoch of such historians, being the most recent around 200 B.C., the epoch of Berossus.

6

These historians talk about the water supply systems for irrigation very naturally, or with no surprise. As a consequence, we can suppose very certainly that during that epoch it was well known that water is a primordial factor for the survival and development of the plants


Growing plants in water, without the use of soil was something well known as we can deduce for the reports of Berossus: “In the water channels, there were beautiful plants that were not planted in soil, but even so were exuberant and always green, and some of them were edible”. They talk too about what we know today as water pumping, when they say: “water from Euphrates River, and was elevated from it to the gardens by an endless thread sys-tem (Archimedes screw) permanently driven by slaves who would take turns”. Plants grown in channels with water flowing in them? This is pure Hydroponics, and the system is known today as NFT (Nutrient Film Technique). The work of archaeologists has been of utmost importance for the knowledge of mankind, when men look for their origins. The discoveries of these dedicated professionals, brought to us reproductions of Egyptian frescoes and hieroglyphics, where it is shown and described floating plantations at the riversides of Nile River. These plantations, probably of edible plants, were carried out on a kind of rafts made up with reeds, over which was deposited a layer of sludge picked from the river. These rafts were put to float on said river. The sludge was kept wet by the river water, and the roots of the plants developed crossing that layer until they reached the water. A similar system was used during a recent epoch by the Aztecs, from whom we will talk opportunely. Marco Polo, about whom we have yet talked, reported us too in his diaries, many details on floating gardens in China, very similar to the Egyptian floating plantations. These reports are typical examples of the hydroponic system we call today Floating Bed System, or Raft System. Born at Stagira in Macedonia in 384 B.C., Aristotle, best known as Atistotle from Stagira, after the death of his father, Nicomanus, the physician of king Amyntas, fixed his residence at Athens, where he became a pupil of Plato in 367 B.C., attending his lessons during 20 years. When Plato died, in 347 B.C., Aristotle changed his residence to Atarnea, in Mysia, where he got married; His wife a relative of king Hermias, provided his admission to the court. In 343 B.C., He became the preceptor of young Alexander after called Alexander the Great, in the court of Philip II of Macedonia.

In 335 B.C. he comes back to Athens, where he establishes his own school, The Athen Lyceum, also denominated the Peripatetic School, because the master ministered his classes walking with his pupils. After the death of Alexander the Great in 323 B.C., he has been hardly persecuted by Anti-Macedonian Greecks, and then he was condemned to death by the Areopagus (the Supreme Court of Athens), after a hideaway in the Euboea island.

7


His wide philosophical work which made him famous is well known, but his scientific work was so or much more important than it. He wrote the “Historia Animalium”, where he registered the description of more than 400 animal species, including “Man”, and in this work he made the first attempt to animal classification. Other works of his authorship include “de Partibus Aniimalium (of the parts of Ani-mals), “de Generatione Animalium (of the Reproduction of Animals)” and “de Motu Anima-lium (of the Moovements of Animals).

Fig. 1.5 Aristotle from Stagira (384 to 322 A.C.) His work on this area is considered as the first treatise of mankind history, anatomy and compared physiology. He has been the first scientist that classified animals in two great groups: the ver-tebrate that he denominated as “sanguineous”, and the invertebrate, that he denominated as “bloodless”. We could tell much more about this man, the real personification of the phylosophi-cal and scientific spirit, whose treatises have never been own writing under his hand, being these originated from annotations of his pupils and listeners. However, though not too much reported and of great interest for us, is the fact that Aristotle, a known lover of nature, founded in his school the first Botany Garden that we know, though he has “written” near nothing about plants.

8


We are not certain if he founded the Botany Garden for him to dedicate himself to the study of plants, or if he made it for his pupils to carry such studies, and this really hap-pened with Theophrastus. Theophrastus of Ereso, whose real name was Tirtamas, denominated simply as Theophrastus (the divine prelector), was born at Ereso, in the Lesbos Island. A great philosopher, he was a pupil of Aristotle at the Athen Lyceum, and took the direction of said Lyceum after the death of his master. Probably affected by his master, he dedicated the larger part of his work to the study of plants, and such studies were the origin of his works “Historia Plantarum” and “Causis Plantarum”. “Historia Plantarum” is an introduction with nine volumes, where the author dedi-cates himself to the description and classification of plants.

9

Fig. 1.6 Theophrastus of Ereso (372 to 287 A.C.)

In this work we can find various sections dedicated to the recognition of plants and its various formats, differences among various types as trees, shrubs and herbaceous, and a series of topics that include habits, geographic location and more important usages. In “Causis Plantarum” a work with nine volumes, we find the theory that supports the facts of the previous work. Here, Theophrastus explains the different actions that nature causes to plants, such as climatic conditions and soil conditions, making comparisons to the actions of man on them, as irrigation, fertilizing and handling.


He also shows us his conclusions about the impossibility of survival of plants in the absence of water, and about the viability of plant survival, be it temporary or permanently, in plain water, considering that the best conditions are with water with the addition of soil residues. In his work, very similar to Aristotle’s in "Historia Animalium", Theophrastus classi-fies plants as Trees (the plants near perfection), Shrubs and Sub-Shrubs (Small plants with woody stems and branches) and Herbaceous Plants. He also divides the plants in Roots, Stalk and Branches. He does not consider as essential parts of the plants the leaves, the flowers and the fruits, as they are of annual renewal and not perennial parts. Theophrastus considers that plants are constituted of elementary substances, as sap, fibers and flesh or core (heartwood). He still affirms, that the fundamental parts are common to all plants, and that their arrangement and appearance, provides the basis for its classification. Both Aristotle's system as that of Theophrastus, built the foundations of the actual science we know as Botany. Even the terms he used to describe the parts of plants, are used until today. The concept of flower (anthos) he used, as being the part of the plant that sur-rounds and protects the fruit, whatever is its appearance, is used until today too. In the same way, until today we use the concepts of single and compound leaves and the one of Pericarp (perikarpion) as being the coverage that protects the seeds. The work of Theophrastus proportioned to posterior scientists, like Carolus Linnaeus (or Carl Von Linné – 1707 to 1778), the establishment of biological nomenclature for plants and animals that he describes in his book "Species Plantarum" (1753) adopted until today. However, classification of plants of Theophrastus is Artificial, that is to say, it con-siders only the plants and their parts alone, not considering the ambient conditions where they developed, and nor even their utility for human being, to other animals and to other plants too. The titles of the nine books that make up the "Historia Plantarum" of Theophrastus are as follows: I – From The Parts of Plants And Their Composition. From Classification. II – From Propagation Especially Of The Trees III – From Wild Trees IV – From Trees and Plants Especially Those From Districts and Particular Posi-

tions V – From Woods of Various Trees and Their Use VI – From Sub- Shrubs VII – From Herbaceous, Other Not Coronary: Pot Plants, Wild Plants and Similar Ones VIII – From Herbaceous Plants IX – From Plant Juices and Medical Properties Of Herbs In the History of Botany, and indirectly in the History of Hydroponics, there are two names in the Ancient World that deserve stake: Theophrastus of Ereso and Pedanios Dioscorides.

10


Pedanios Dioscorides was born at Anazarbo in Cilicia – Asia Minor, in the year 20 A.C., and he studied Medicine and Pharmacy in the School of Areios, at Tarsus. His great work has been the writing of a treatise about the description and usage of medical drugs obtained from plants, being such work done during the years 60 to 78 A.C., about 400 years after Theophrastus. His work, composed of five volumes, is entitled “De Materia Medica”, is the first sys-tematic pharmacopeia known, and contains the description of about 600 plants, besides 4740 medical usages and recipes of drugs. Unfortunately, once published, it became lost in the Occident, and has never more been reintroduced. Even so, it was preserved by the Arabs, that edited it various times, and by whom it is used until today. Part of his work only begun to be overcome around 1400 by the well known Philipus Aureolus Paracelsus, whose real name was Theophrastus Bombastus von Hohenheim, a medical and alchemist who lived between 1493 and 1541.

Fig. 1.7 Pedanios Dioscorides receiving the mandragora from the hands of the Goddess of Discovery Illustration of the Latin manuscript of the book "De Materia Medica"

In the preface of his book, Dioscorides says that he has travelled very much with the Roman army, but he does not specify if he had the function of a physician or of a pharmacologist. We can believe that he had both functions. There are many evidences that he travelled not only inside but also outside the bor-ders of the Roman Empire, and so he had great opportunities to know and study the most various kinds of plants. Dioscorides always considered himself as a physician, and his work is in sharp contrast to his predecessors, who were physicians, but pharmacists (Pharmakolopoi) or 11


herbalists, also called “root cutters” (rhizotomoi). Even so, in their profession, all they used plants, in various degrees of practice and education. The Five volumes of “De Materia Medica”, each one with its own preface, are: Book I – Aromatic (or spices), Oils, Pomades, Trees and Shrubs (Liquids, Resins And Fruits) Book II – Animals, Parts of Animals and Products, Cereals, Pot Herbs and Strong Herbs Book III – Roots, Extracts, Herbs and Seeds Book IV – Herbs and Roots Not Discussed Before Book V – Wines and Minerals The description and classification of the plants he studied, always follows the same

1- Name and synonyms if they exist 2 - Habitat 3 – Physical description 4 – Proprieties as a drug 5 – Medical use 6 – Side efects 7 – Recomended dosage 8 – Harvesting methods, storage and preservation 9 – Detection of possible adulteratios 10 - Veterinary uses 11 – Magic or non medical utilities 12 – Specific habitat and where plant can be found In his work, a question always arises: What did Dioscorides wanted to say when he talks about the properties of the plants? The list of those properties for each plant is very extensive. Generic descriptions include heating, pacification or softening, astringency, diuretic properties, drying, cooking, concentration, dilution or thinning, sleep induction, relaxing, cleanness, hardening and sus-taining power. In his classification of plants, Dioscorides lists all the properties associated to each particular plant, leading us to a myriad of possible combinations, and that is why his classi-fication is considered as a natural one. The richness in the details of his books, even those translated to Latin and specially those translated to the Arabic, forced us to transmit to our reader a part of them, even we know that we are sinning in the extension of our words, that at the first sight seem to es-cape to our principal subject. But the legacy of Dioscorides to us is so valuable, that until our days in all Europe, his detailed information and profound teachings are the basis of phytotherapy, with which we can get the healing of many diseases that affect men and other animals. As if this were not enough, it part of his legacy the informations which refer to ambient conditions needed to the production of medicinal herbs and aromatic spices under controlled environements, which are of utmost importance for the hydroponicists to use them in the several variants of the hydroponic technique. Many experts claim that cited herbs produced by hydroponics do not have the es-sential elements which give them the taste, aroma, and healing properties.

12


13

Fig. 1.8 Plant and its details – Illustration of the Latin Manuscript of the book “The Materia Medica”

Fig. 1.9 Pedanios Dioscorides and the Roman Legions


14

Fig. 1.10 Pedanios Dioscorides and a pupil – Arabic Manuscript of the book "De Materia Medica" Illustration by Yusuf al Mawsili - Mosul – 1228

That’s not true. It is not a determinate soil which proporcionates the needed or searched characteristics of a plant, but it is the ambient and nutritional conditions we pro-porcionate to it, that enable us to reach said characteristics. The human being bears inside himself an immense destructive capacity that not only hits the environment as a whole, but also all that is around him. As a consequence, who knows, very soon, we will be forced to search for natural medicines made from veget-al species hydroponically produced. This will be a great responsibility that hydroponicists will have to assume, and they must be prepared for that. That is why we gave here such a great value to the work of Dioscorides, though he never gave us any direct information that could be considered as a real part of the History of Hydroponics. Long before the rise of Aztec Empire, the today called Central Mexican Valley was the center of a highly developed civilization. A very fertile basin, the valley is located around 2,400 meters above sea level, and at its center there are five lakes that are naturally connected with one another, in which there are some swampy islands.


15

Fig. 1.11 Vine with fruits and details – Arabic Manuscript of the book "De Materia Medica" Illustration by Yusuf al Mawsili - Mosul – 1228

Between the years 100 and 650 A.C., the North Mexico was dominated by the Tol-tec people, gathered around a city called Teotihuacan, which was the center of a political, religious and financial state. With the decline of Teotihuacan, the Toltec people migrated from the North to the Central Mexico, where they established a state of conquest. Here the Toltec civilization reached its pinnacle between Sec. X and Sec. XII. During Sec. XIII, the valley was invaded by a series of bands of stray warriors, the Xiximecas, whose principal characteristic was that all they spoke the Nahuati idiom. They conquered various Tolteca cities, as Atzcapotzalco, and they founded other ones, as Texcoco de Mora. The Xiximecas gradually combined their cultural traditions with those of the Tolte-cas, thus starting the old Aztec civilization, whose social structure, economy and art, would reach its maximum exponent during the so called Last Empire. The group is believed to have founded the Aztec Empire was that of the Mexicas, around the mid of Sec. XIII.


Fig. 1.12 Mustard plant with seeds and details-– Arabic Manuscript of the book "De Materia Medica" Illustration by Yusuf al Mawsili - Mosul – 1228

This group, composed by hunters, and being the last one to arrive, was pushed by the groups yet established, to two islands in the western side of Texcoco lake, one of the five lakes of the valley. The Mexicas believed in a legend by which they should establish a great civilization at a swampy place in which they must see a cactus growing from stones, having an eagle perched on it. 16


When they arrived to the swampy side of the lake’s beach, their priests stated that they had the vision of the cactus and the eagle, and so claimed that they arrived to their destination. The site ended up becoming a strategic point providing good sources of food and water for river transport. The Mexicas begun their lives at this site, dedicating themselves to a sustainable agriculture, and in 1325, at one of the islands of the lake, they founded the city of Tenoch-titlan. To maintain secure against the invasion of other groups, during 100 years the paid tributes to neighbor more powered groups, especially to the Tepanecs, from the state-city Azcapotzalco to whom they worked as mercenaries too. By the growth of their population, the Mexicas grew not only military but also in the civilian organization, and slowly begun rebelling against the Tepanecs, and so they could control part of the territories of the lakeshore. Around 1427, the Mexicas of Tenochtitlan made a triple alliance with the state-cities of Texcoco and Tlacopan (today called Tacuba). Under the command of the governor of the Mexicas, Itzcoatl, his successor Monte-zuma I and the Texoconian governor Netzahualcoyoti, the three states begun a series of conquers, and by them, they established their empire, extending from Central Mexico to the borders of Guatemala. These conquests included various state-cities and ethno groups, who were forced to pay tributes to the alliance. By this time, Tenochtitlan assumed the dominant power within the triple alliance. The economical basis of the Aztecs was agriculture. The lands of the lakes were too scarce even they were fertile, and the conquered lands at the lake beach, though fertile too, were not sufficient to produce food in the needed quantity for the growing population. To make the beach lands more fertile, even being in the hillsides around the lake, the Aztecs developed irrigation systems, they formed terraces in level curves, and begun using natural fertilizers to enrich them. But their most important agricultural technique they developed before the conquest of the lands of the lake beaches has been the “chinampas”, also known as “floating gar-dens”. These were small floating islands created artificially, over which they planted edible greens, corn (their basic food), fruitful shrubs and flowers. Their construction began by the building of large rafts made up from bundles of junk and reed firmly tied with one another. After putting them to float, they were filled with muddy soil highly fertilized they re-moved from the bottom of the lake, which was very shallow, thus formatting a substrate.

17


18

Fig. 1.13 Engraving showing Chinampas

This substrate where plantations were carried was kept very wet, as the water where the chinampa floated irrigated it by capillarity. Plant roots grew, crossed the soil layer and the layer of reeds, and reached the wa-ter. The plants continued to develop until the roots reached the bottom of the lake where they anchored. As the soil became depleted in nutrients, another layer was placed, and the raft be-gun to deep until it reached the bottom, forming a permanent island. Then, to avoid the landsliding of the soil inside the lake, during the beginning of the formation of the chinampa, they planted willow seedlings on its borders. The willow roots developed until the bottom of the lake, and after anchoring there, they formed trees, that avoided landsliding of the “artificial island”, and at the same time, they served as wind breakers, providing the shading of the plants too. Before becoming anchored in the bottom of the lake, the chinampas were relatively mobile, and they were more used to prepare plant seedlings, besides the plantation of edi-ble greens and floral species. It is said that during fair days they were dragged to the borders of the lake, and har-vesting was made in the selling moment. The chinampas were built side by side, becoming amended, and between them channels were formed, by which the farmers moved up with flat bottom boats to reach their plantations.


The success of this technique then began being used as a process to drain the swampy borders of the lake. Here, rows of willows were planted and when they reached a convenient height, a floating and sufficient long chinampa was built between each pair of those willow rows. Then the marsh land was removed and placed over the chinampa, thus forming layers that were interweaved with other layers of reeds. These layers were anchored laterally by the willows and then begun slowly sub-merging until they reached a solid soil layer, thus forming solid soil windrows separated by water channels by which the farmers dislocated their boats. By using the same process, the Aztec farmers built connecting bridges between the islands and the lake borders. Well, the chinampas are something very similar to a hydroponic system we call to-day Floating Bed System or Raft System, though we have many doubts about that, which timely we will explain. In 1519, the Spanish explorer Hernán Cortéz in the company of 500 soldiers landed at the East of Mexico, looking for gold and new lands. Advised by Malinche, his South American native concubine, Cortéz formed an al-liance with the Tlaxcalans, rivals of the Aztecs, and addressed himself to Tenochtitlan where by that time governed Montezuma II, who vacillating about how to face the Spanish, invited them to the city, not only to know them better, but also to evaluate their intentions.

19

Fig. 1.14 Water channels between actual chinampas - Xochimilco - México


As they found great quantities of gold and other treasures, and afraid that Monte-zuma could defeat his small force, Cortéz imprisoned him. All the gold ornaments they found were cast to make their transportation easier, and Montezuma was forced to swear allegiance to the King of Spain. The Spanish stood in the city for about six months with no opposition from the Aztecs, and during this period Cortéz went back to Spain.

20

Fig. 1.15 Model showing the construction of swamp draining chinampas

1.16 Hernán Cortéz (1485 to 1547)


With the return of Cortéz, the Aztecs revolted, expelling the Spanish from Tenochtitlan, they destroyed the access bridges to the city, and hunted the enemy in the channels of the chinampas, making them to retire to Tlaxcala, where they rounded up more native allies. Back to the attack, Cortéz defeated the Aztecs in 1521, whose simple weapons could not overcome the steel and the cannons. Cuauhtemoc was tortured and hanged during an expedition to Honduras. Then the Spanish destroyed all the rest of the Aztecs, took over their lands, and the survivors were made slaves to work in the gold mines in Mexico. The fall of Tenochtitlan marked the end of the Aztec empire, one of the greatest civi-lizations of the world, and one of the only Native American civilizations. Tenochtitlan was razed, and over it today is built Mexico City. Its Cathedral was built over the Great Aztec Temple, and the government palace, over what someday was the palace of Montezuma. But, probably to grant their food supply, the Spanish didn’t destroy the chinampas, and many of them, even in reduced quantity, are still functioning. Descendents of the Aztecs still take care of the chinanperian agriculture, in the great majority, producing flowers. As time went by, a great part of the chinampas surrounding Mexico City were landed, as well as almost Texcoco lake, as a consequence of the enlarging of the city. The great majority of the remaining chinampas has been well preserved on the re-gion of Xoximilco, one of the 16 delegations of the Federal District of Mexico. Perhaps the rivalry between Xochimilco and Mexico City-Tenochtitlan, that exists since Sec. XIV, epoch when for the first time it was conquered and dominated by the Aztecs for it to be supported by its agricultural products, has caused inattention to Mexican authorities with this beautiful region. However at December 11, 1987, the UNESCO signed up Xochimilco in the list of the Monuments Belonging to Mankind History. The historic facts we narrated here, though some extensive, give us before anything a better understanding of the situations that leaded an entire civilization to look for solu-tions to preserve its survival. We have no doubts that it was a relatively slow process full of trials and errors along which a series of knowledge was acquired. The difficulties of that people must be analyzed by means of all what we reported here, and compared with actual similar situations. Don’t our reader thinks that the inhabitants of many regions of our planet or even of our country are waiting too much for someone to solve their feed difficulties without facing seriously their problem and look for their own solutions?

The Aztecs looked for solutions, and they found them. So much that they formed,

21


within certain limits, the basis for a more modern technology, which is Hydroponics. But if we analyse the historical facts with more attention, a question rests to be answered. Did that people based at the North of Mexico, whose origin we don’t know, had to discover their agriculture process, or they were yet its owners. After all very similar processes much more near of what today is the Floating Beds Hydroponic System, existed in Egypt and in China, during epochs before the Aztecs. That is why here is the time and place to put some restrictions about the similarity or even about some conclusions that confirm the chinampas as being floating gardens com-parable with the cited hydroponic system. The reports of the scriveners of the expedition of Cortéz speak about those gardens and agricultural system with a great wonder, as they have never seen or experimented such an efficient and productive system. In the same way, those reports speak about the highly developed and organized cities in a region so distant from Europe. This way, some myths were developed that remain until today, and are still kept and spread by tourist guides at Xochimilco. We must understand that pure or real Hydroponics is an agricultural technology by which soil is not used, and with it the plants are kept with the roots partially or totally im-mersed in water in which are dissolved and ionized all the nutrients needed for their devel-opment. That’s why Hydroponics is also known as Soiless Culture. However the chinampas are constituted by a confined soil formed by the sludge of the bottom of the lakes, disposed in several layers interleaved with aquatic plants which are used as a green fertilizer too. Besides that, according to historical reports, the Aztecs used human feces to refer-tilize the soil of the chinampas, and they controlled that fertilization with culture rotating. We cannot safely affirm too that the chinampas were floating gardens that during the days of fair were dragged to the borders of the lakes for the marketing of the products. May be that could be possible during the beginning of their construction, and even so we must understand that they were considerable heavy for that, as their dimensions ranged around ten meters wide and near one hundred meters long. What in fact we can say is that the chinampas were a system that was developed to drain the waters of the lakes and their swampy borders. The channels between the chinampas were sufficient wide for the passage of two boats side by side at the same time, and really were used for moving from one another to transportation of the products. . We must remember that the Aztecs didn’t know the wheel, and their loads were transported in bags or baskets loaded in the backs of the farmers. Moving those loads on boats made their work easier.

22


Besides this, the lakes were rich with fishes, and the channels made fishing easier, as well as aquatic birds hunting. Other local aspects must be considered too, which can show us till where that people was developed respect agricultural techniques. The water of the lakes was too salty, and that salinity till some extent, was balanced by the waters originated from the defrosted snow of the surrounding mountains that some-times caused disastrous floods. Thus this people developed the construction of very wide stone dams, provided with regulator floodgates separating the more salty waters of some lakes from the sweet wa-ters. These dams also served as circulating ways for pedestrians, and over them they also constructed gardens, using the sludge withdrawn from the bottom of the lakes as a fertile substrate. After the destruction of the Aztec, Cortéz dismantled those dams to use the stones in the construction of the New Mexico City leaving the waters free to flood and to make surrounding lands fertile. He indeed distructed such lands, salinizing them with the salty waters of the lakes. This way many chinampas had to be rebuilt as they were the basis of the nourish-ment of the Spaniards. Even so, though it is told that Cortéz didn’t destroy the chinampas and the chinam-perian agriculture, he really provoked in a large scale their destruction as well as he de-stroyed a whole civilization and all its advanced culture. As told before, we don’t see any similarity of the chinampas with any actual hydro-ponic system. But the myth was created, and we believe it will be kept for years and years. Regarding Cortéz, we leave to our readers the task of researching a little more on the History to make up his own opinions. Along the History we find men that dedicated themselves very hard to the problems of plant nutrition, and all they reached the same conclusion: without water there are no plants. That is why we believe, as we told before, that everything and everybody that along the centuries showed or proved that water is a prime factor in the survival and develop-ment of the Vegetal Kingdom, are part of the History of Hydroponics. As an example, we can ask: What is the relationship between Leonardo da Vinci with Hydroponics? Very few people exist that have never heard about this eminent personality, at least about his art works. But he was one of the major inventors and researchers of mankind, leaving to us a

23


great scientific heritage. Leonardo da Vinci was born at a hamlet called Anchiano near of the Tuscan city Vinci, close to Florence, in Italy at April 15, 1452. He was an illegitimate of Antonio the older son (25 years old) of Ser Piero, with Ca-therine, an underage peasant. (”Ser” – a title given to the professional or a member of a traditional family of public notaries and lawyers) Ser Piero was married with Albiera di Giovanni Amadori, that was only 16 years old, and it is told that she was his fourth wife. Ser Piero had eleven children. Leonardo was left-handed, and even it was a habit at that epoch, he never had the opportunity to correct that characteristic. May be this made him easy to write in a mir-rored way, from right to left. He had no chances to attend suitable schools, and so he didn’t know Greek or Lat-in. May be due his little schooling, Leonardo was more cleave to visual images and to oral communication, using his Italian Tuscan language.

24

Fig. 1.17 Leonardo da Vinci (1452 to 1519) – Self portrait in charcoal over paper

His lack of knowledge of Greek and Latim, impeached his access to books that could directly provide him an enlargement of his knowledge, beyond those he could get by humanistic books written in Tuscan.


We could here write many things about the life of Leonardo, but the most important part for us, refers to the last seven or eight years of his life. We must remember here that in 1499, the French army had invaded Milan, at that time under the domain of Ludovico Sforza, deposing him. As a consequence of a new war that erupted at the North of Italy, Leonardo came to Rome in September 24, 1513, where he carried out many experiences in Chemistry for Giuliano di Medici, brother of Pope Leon X, who was his employer by that time. Here he took to develop his knowledge of human anatomy, and engaged in the manufacture of lenses and mirrors. Giuliano di Medici had ordered to Leonardo a deep research about how to increase his agricultural production at his properties, whose result he never presented, because during a trip to Bologna, in 1515, he knew the then French king Francis I, who took him to France, putting him at his service. The king hosted him at the Chateau aux Cloux, at Ambroise, at the border of river Loire. And here, Leonardo continued his agricultural research, whose results he presented to the king of France. On his writings he said: “To develop, plants need mineral elements that they absorb from soil by means of water. Without water the plants don’t survive, even in soil they have the mineral elements they need.” “Water is as if it were the soul of plants, as mineral elements are as if they were the soul of soil”. If we could transmit to the soul of plants the strength of the soul of soil may be we would not need it to make plants survive and multiply”. “I believe that in a future that does not belong to me, that will be possible”. “So it is advisable to fertilize and irrigate periodically the lands for us to get a healthy and productive plantation”. Leonardo da Vinci was a visionary? It’s difficult to believe. However we can verify that by his experiments Leonardo yet foresee the principles that today rule the hydroponic technology, or better, to cultivate plants without soil. Leonardo da Vinci died in France, in the Chateau aux Cloux, at Ambroise, in May 2, 1519. During the years after the death of Leonardo, there are not many studies on plants, and not even records on the use of his advisements and guidance. After the epoch of Leonardo, though we could have some advancement on Botany

25


the researchers dedicated their work towards the classification of the plants, and not to plant nutrition. Probably the scarce knowledge of Chemistry existing by that time gave a great con-tribution to a certain interruption in the studies of plant nutrition, but it was yet a proven fact that water was the major element for plants to be able to survive. Only during the epoch of transition from Alchemy to Chemistry, and even during some intervals of the last one when we had some discoveries in this area, we verify the restart or recovery on studies on plant nutrition. But a profund knowledge on plants, not only those for food but also those used in medicine, has always been the goal of scientists. And we are sure that knowledge is an integral part of the History of Hydroponics, because it is based on it that we know how to deal with hydroponic plants. Based on this, we believe as being part of the History of Hydroponics those scien-tists and researchers that dedicated with all their strength to the enlargement of our know-ledge about plants, others that are not only those related to their nutrition.

Fig. 1.18 Luca Ghini (1490 to 1556) Let us cite Luca Ghini born at Croara, next Imola, in Italy in 1490 and dead in 1556.

Ghini graduated in medicine in Bologna in 1526, where he began his career in uni-versity teaching.

26


Between 1543 and 1526 he moved to Pisa, invited by the Great Duke Cosimo I de Medici, where he founded the “Orto dei Simplici”, a Botany Garden dedicated to the culture and study of medical herbs for didactic use in the University.

Luca Ghini was the first botanical to use dried plants for the purpose of studies thus creating the first herbarium of the world. An assiduously follower of Dioscorides, whose work “De Materia Medica” was his didactic book, he oriented his classes in the practical way, though even then also criticize the book for which he directed. After founding the Botany Garden of Pisa, which was the first academic garden of that kind in the whole world, still under the invitation of Cosimo I de Medici, in 1544 he funded the Botany Garden of Florence, which in antiquity was the third of the world after the one of Pisa and the one of Padova. The garden of Florence, also funded for the studies and culture of medical herbs, was after transformed into the Experimental Agrarian Horto, devoted to the studies of not only medical herbs but also of plants for feeding and other ones of scientific interest. By this time, the knowledge of Alchemy began expanding, and we could yet glimpse the birth of Chemistry as a science.

27

Fig. 1.19 Philippus Aureolus Paracelsus (1493 to 1541)


By this time, with Paracelsus, began the use of chemical products to heal some dis-eases. Philippus Aureolos Paracelsuls, whose real name was Theophrastus Bombastus von Hohenheim, was Born in Switzerland in 1493, and died in 1541. He was a physician and alchemist, and his scientific work marks the beginning of the Science of Chemistry based on Alchemy. He believed on the three fundamental principles of the Arabian Alchemy that con-sisted of Mercury (characterized by fluidity, by weight and by metallicity), by Sulfur (cha-racterized by the flammability principle) and by the Salt (characterized by the principles of solidity and relative chemical inertialty). Paracelsus is considered the father of modern pharmacology, as a consequence of his work in healing diseases by chemical treatment and not phytotherapeutic. Even being basically an alchemist, he concluded that the finality of Alchemy was not the production of gold (the Philosophical Stone or Touchstone), but to prepare mixes of chemical medicaments to heal diseases. Paracelsus was the first physician that applied scientific principles in medicine, and he was responsible by the combination of Iatrochemistry and Alchemy, and for that rea-son, as we told before he became the precursor of the modern Pharmacology. However his contribution for science was always followed by an incomprehensible adhesion to the mystical side of the Alchemist research, though he was a great experimen-ter always anxious to better understand the human body. Though more turned to medicine, he was however one of the great researchers on Chemistry, especially on the search and use of pure chemical composts. A physician, philosopher and naturalist, Andrea Cesalpino was Born in Italy, at Are-zo, in Toscany, at June 6, 1519, and died in Rome at February 23, 1603. His great work, that distinguished him above everything, was in Botany at the Uni-versity of Pisa, where he was a pupil of Luca Ghini. After the death of Ghini he assumed the direction of the Botany Garden. At the University of Pisa, he was a teacher of Phylosophy, Medicin and Botany dur-ing many years, and yet with advanced age, he was called to Rome, where he became a teacher of medicine and private physician of Pope Clement VIII. It is a belief that once in Rome he also assumed the direction of the Botany Garden of that city, funded in 1556 by one of his pupils, Micheli Mercati. The great work of Cesalpino that made him immortal, is in his book “De Plantis Libri XVI”, published in Florence in 1583, and before Linnaeus, it is the greatest work ever writ-ten on Botany. It is incredible, but this book has no illustrations, which is a great contrast with the work of Dioscorides. We owe to Cesalpino the proposal of an innovation on the systematic ordering of plants, based in their biologic character that also contains the morphologic structure of their principal parts, as well as their nutrition and reproductive apparatus.

28


Assiduous critic of Aristotle and Teophrastus, that used to establish analogies be-tween plants and animals, Cesalpino separated completely vegetables from animals, to perform his proposal of plants classification, that however being an artificial classification, had a good parcel of natural classification.

29

Fig. 1.20 Andréa Cesalpino (1519 to 1603) Cesalpino also used dried plants for his studies, and he mounted several herbaria, one of which and the most important, during the years 1550 to 1560, to Bishop Alfonso Tornabono. This herbarium was compiled at the Botany Garden of Pisa, and is kept at the Bota-ny Museum of Florence. It’s composed of three volumes bound with red leather with a total of 260 pages containing 768 plant species. It is after Cesalpino that the ways of Hydroponics, as a soilless culture, begin ap-pearing again. This resurgence appears not only by experiments with plants, but also more asymp-tomatic by the discoveries in the area of Chemistry, where the chemical composts as well as their elements begin being identified and being prepared in palpable marketable quanti-ties. Several prominent figures of History had their participation during this phase, includ-ing some that may seem very strange in the scientific area. This is the case of Francis Bacon, born in London at January 22, 1561, and dead in the same city at April 9, 1626. Youngest son of Nicholas Bacon, Lord Guardian of the Royal Seal of Queen Eliza-


beth I, he was admitted to the Trinity College in Cambridge, where he was graduated as a lawyer.

30

Fig. 1.21 Francis Bacon (1551 to 1626)


Named Count of Saint-Alban and Baron of Verulan, he was also awarded as Empe-ror of the Rose Cross Order in England, and was one of the persons that more contributed to the transmission of the interior knowledge, by which he is considered by many people as the father o modern science, once he was the promulgator of empiricism, or the expe-rimental verification. He created the philosophy of the scientific method (Hypothesis → Experiments → Conclusions). Though being a great philosopher, he also was a great experimenter in Chemistry, and in his work with Sulfur and Mercury, he reached to a series of important conclusions. He concluded that water is the major food for plants, and that the principal function of soil is to keep plants in a vertical position. He also concluded that plants retire their nutrients from soil by means of water, and if we cultivate a plant in a determinate volume of soil, it will retire all the nutrients existing there, until that parcel of soil has no conditions to feed the considered plant. In that epoch, till a certain extent those were revolutionary conclusions, but we must consider that the knowledge of chemistry was very scarce, and as a science, the Chemi-stry was beginning its first steps, independently of Alchemy.

Fig. 1.22 Jan Baptiste van Helmont (1577 to 1644)

31


Everything began with Johanes Baptiste Van Helmont, or as he is generally known, Jan Van Helmont. He was born in a noble family from Belgium, in Brussels, at January 12, 1577, and died at Vilvorde, also in Belgium, at December 30, 1644. He studied at Louvain, where he graduated in Chemistry, Physics and Physiology, and exercised those activities without a self satisfaction, abandoning them to study medi-cine. He graduated in Medicine at Louvain, and developed too his studies in Classical Philosophy, Geography and Law. He has graduated too in Astronomy, Logics, Geometry and Algebra. During many years he travelled through Switzerland, Italy, France and England, and returning to his home land, he fixed his residence in Antwerp during the great plague of 1605, where he hired a rich marriage after which he fixed his residence at Vilvorde in 1609. Van Helmont presented curious contradictions. From one side he was a great disciple of Paracelsus, though he spitefully repu-diated its mistakes, and at the same time he was a mystical with great tendencies to the supernatural. At the same time he was an alchemist believing that with a small piece of stone he could transmute it in a quantity 2,000 times larger of Mercury or of Gold. On the other side, he was touched by the new knowledge that produced celebrities as Harvey, Galileo and Bacon, being at the same time a grat observer of nature and an exact experimenter that in certain cases concluded that matter cannot be created or de-stroyed. As a chemist it is credited to Van Helmont the position of founder of pneumatic chemistry, though this knowledge flourished one century after his death. He was the first one to understand that exist distinct gases in atmospheric air. It is credited to him the invention or the creation of the word “gas”, and he affirmed that the "wild gas” (our actual carbon dioxide) produced when burning charcoal, was the same produced by the fermentations, making the atmosphere of the wine caves some-times intolerable. He vehemently denied that neither fire nor earth were elements, and that these could be converted to water. He stated that plants, for example, are basically constituted by water, a belief that took him to his great experiment, which became fundamental for the History of Hydropon-ics. He was a zealous catholic, and even so, in 1625, the Spanish Inquisition con-demned 27 of his prepositions, for heresy, blatant arrogance and association with the Lu-theran and Calvinist doctrines. His great work, the treatise “De Magnetica Vulnerum”, has also been impugned in the next year, and it still was condemned by the University of Louvain from 1622 to 1634, because he added to the ideas of Paracelsus.

32


In 1634 he was taken into Ecclesiastical custody for four days, and then he was transferred to the Minorite Monastery at Brussels. After several interrogatories he was put under domiciliary imprisonment which has been revoked in 1642, but even so the Ecclesiastical prosecution against him continued until the end of 1642, and only in 1646, after his death, his widow received his official rehabilitation from the hands of Archbishop of Malines. Even so he got the Ecclesiastical “Inprimatur” for his treatise between 1624 and 1642. That is why Van Helmont didn’t publish anything between 1624 and 1642. Though he was a physician his career on that was very short, because as a per-sonal principle, he refused to earn a living by the suffering of his similar, a reason for him to practice medicine for free. However he was one of the most active physicians during the great plague of Antu-erpia in 1695. In 1609, by his marriage with Margarita Van Ranst, of the Flemish upper middle class, he assumes as feudal lord in Merode, Royenborch, Oorschot and Pellines and from the taxes collected here he gets his profits with which he subsidizes his works and scientif-ic researches. In this regard, Van Helmont has never received subsidies, and he even refused such earnings offered by Ernst of Bavaria, Mathias and Ferdinand II. He was also pre-sented to the Queen of England, but he refused her offers too. It is said that the only help he accepted was the interference of Maria di Medici in the lawsuits filed by the church against him, a fact that until today has not been confirmed. According to the National Biography of Belgium, Van Helmont was a member of the Rose Cross Order, but this is not confirmed by other authors. Professionally, besides medicine that he practiced free of charge, he was a great researcher within Iatrochemistry, Pharmacology (a follower and practitioner of the ideas of Paracelsus), and in Botany he was one of the great researchers on plant nutrition. The great experience (for that epoch) that marked the presence of Van Helmont in the History of Hydroponics comes from 1600. Our scientist planted a willow seedling weighting 2.5 Kg in a pot with 100 Kg of ferti-lized soil well covered to avoid the reception of dirt or any other strange element. During 5 years he irrigated this plant with filtered rain water. After this time he weighted the parts, and verified that the willow increased 80 Kg in its weight while the soil used only lost 1 Kg of the initial weight. Van Helmont considered the soil weight loss as a measurement error, and he con-cluded with pertinency that plants feed and develop on water. Considering that by that time the photosynthesis process and much less Carbonic Gas nor Oxygen were not known, and that water dissolves nutrients of soil completing with them their nourishment, Van Helmont was correct.

33


The importance of this experiment resides in that it was directed to proving the nou-rishment of plants with water. Facts that until then were just suppositions and eventual conclusions from secondary or parallel results of experiments or observations that showed the plants need water to survive and develop, from then on, was something proved. However Chemistry begun getting established as a science, and its development proceeded. And as always happened at that time, to obtain chemical products, at least the commonly known, be them for laboratory as well as for medical and pharmacological use, were a constant difficulty. This situation begins reversing with Johann Rudolph Glauber, born in Karlstadt in Germany in 1604, and dead in Holland, at Amsterdan in March 10,1670.

Fig. 1.23 Johann Rudolph Glauber (1604 to 1670) Glauber, son of a barber, Rudolph Glauber had no academic education, and started his education at the Latin School of Karlstadt, never concluding it. However he became autodidact in Chemistry, Alchemy, Iatrochemistry, Pharmaco-

34


logy and Metallurgy, and travelled a lot to Paris, Basel, Salzburg and Vienna. For his livelihood he worked in Pharmacies, especially in Giessen, and dedicated to arts too. He also worked in the manufacture of cast metallic mirrors. In 1635, he began his work as the Court Pharmaceutical, in Giessen, and in 1654, he gifted Archbishop of Mainz with his process to produce tartar to grant him some privi-leges, which he finally got in 1652. He was a medicament producer, which sometimes he prescribed personally and for free. Such medicaments were normally based on Antimony, which was a new directive in Pharmacology. But his professional life, temporary, was dedicated to the wine industry, and by his firm Dess Teutschlands-Wohlfahrt (de 1655 a 1661), he defended the exportation of wine and beer, offering recipe of stable concentrates easily exportable. This was one among other innovations in the agricultural industry that Glauber car-ried out to increment German commerce, helping the country to recover after the war. He developed various works in agriculture, recovering soils in infertile zones near the beaches, using chemical fertilizers based on tartar and derivatives of wine. In his laboratory at Amsterdan, he studied the effects of various treatments in agri-cultural products. In this city he also supported himself selling chemical products of his manufacture, among which the Sodium Sulfate, that he discovered, and that till our days is commercially known as Glauber Salt. Natural Sodium Sulfate, in his honor is called Glauber Salt too. He was able to separate Potassium Nitrate (Potassium Salpeter resultant of fer-mented Urea), from soils for trampling chickens breeding, and applying it to arable soils, he verified its result in the increment in crops. By this time he categorically stated: “Salpeter is the principal food for plants. As animals eat the plants and Salpeter comes from those plants, it is recycled to the soil by the animal’s feces”. This has been the first admission of nutrients recycling in Nature. Indeed the Salpeter that Glauber separated was the result of the hydrolysis of urea that decomposes forming ammonium and carbonic gas, by the catalytic action of urease, an enzyme produced and excreted by a series of soil microorganisms. The resulting ammonium nitrifies producing the nitrate ion that reacts with Potas-sium, also found in the urine of animals, forming the Salpeter or Potassium Nitrate. As can be seen, Glauber, an autodidact, besides the contribution he gave to agricul-ture in the field of fertilization, was really the first manufacturer of chemical products in an industrial scale. What is the importance of these facts in Hydroponics? Without water soluble min-eral salts to prepare the nutrient solutions, Hydroponics becomes extremely difficult, and in some cases, impossible.

35


It is important to remember that formerly, any person attending a university, besides his home language, learned Greek and Latin. That is why the books written by scientists, and even the majority of didactic books were normally written in Latin, recognized as the universal idiom. When some scholar or even scientist had not attended at least a good level school, and did not know Latin and Greek, his access to scientific works was very difficult if not impossible. This has been the case of Leonardo da Vinci. Very rarely scientists had to study such idioms privately, with some master or even by themselves. Da Vinci has been one of them. In the same way, many scientists today renowned had their works forgotten or rele-gated to a second plane, because they were not written in Latin. Only in recent time we began knowing their work, as they were translated into idioms modernly more accessible. Today we face a reverse situation. Latin and Greek are no more taught in common schools and universities, unless one wants to devote himself to those languages. This way, for us it becomes difficult the access to works of ancient scientists, unless we have in hands translations of the same to our idiom, or at least to idioms today consi-dered as international, like French, English and Spanish. And when we read works recently translated, we face many times with facts and knowledge we believed to be recent, but in truth they were discovered centuries ago. A very interesting detail is that the greatest part of scientists and even liberal pro-fessionals formed in ancient universities, were philosophers too. Besides that, their aca-demic studies though directed to a determinate activity, enabled them to other ones. Stu-dies were horizontalized. This is why we find, for example, that a physician, at least, was also Philosopher, Chemical or Alchemist, and according to the epoch, Pharmaceutical and Botanical. We cannot forget that until Paracelsus, medical therapies were natural, and the drugs basically phytotherapeutic, as a general rule were prepared and furnished by the physicians. It is very easy today relieving heartburn with a small amount of Sodium Bicarbonate dissolved in water. For us it is very easy simply breathing, or using our blow to fill those rubber balls that ornament birthday parties of our children. In the same way, it is easy and rapid for us, at the laboratory, to know if determined solution is alkaline or acid. We just immerse a small paper strip, and when its color changes we have our answer. Today, who doesn’t know that air pressure inside automobile tires grows during hot days and decreases during cold ones? No doubt that 300 years back we had no rubber balls to fill nor automobile tires to calibrate their inside pressure, but we had acid and alkaline solutions to identify, and we

36


had heartburns to heal. And that was not so easy. To know what time is it? It’s easy. Just look to your wrist and read your watch. But, 300 years ago we had to consult the watch at the tower of the church or to pay atten-tion to the tolling of its bells. What is the relation of this all with the History of Hydroponics, or even with Hydro-ponics itself? There is a great relation. If we can’t keep a correct period between irrigation cycles in our hydroponic culture, we will never get the desired productivity of our plants. For that, we need to measure the irrigation time and cycle, and consequently a watch, whatever it is. On the other side, keeping the correct pH (alkalinity or acidity) of a nutrient solution can make the difference between a good crop and a total loss of our plants. For that we need to know if our nutrient solution is alkaline or acid, and what is the level of that alkalinity or acidity. How? Just by using pH indicator strips or a pH-Meter. Solutions for small problems as those we exposed began with experiencies of vari-ous scientists, some hundreds of years ago, and among them we can cite Robert Boyle. The seventh son of an adventurer at the service of Queen Elizabeth I of England, from whom he received a great prestige, Robert Boyle was born at January 25, 1627 at the Castle of Lismore, Waterford County, in Ireland. He began his studies at the Eaton College of Windsor, and from twelve to seven-teen years he continued studying with his guardian and private teacher in Switzerland, the country he elected to live in until 1644, when he returns to England to live with his sister Catherine, Lady Ranelagh, resting with her for only one year. Yet graduated in Physics, Chemistry and Philosophy, from 1645 to 1655, he lived the greatest part of his life at Dorset, where he began his experimental work, and the writ-ing of several morality essays. He returns for a short period to Ireland, where, as he had not a laboratory, he dedi-cates to anatomic dissection. From 1656 to 1668 he fixed his residence at Oxford, where yet with good financial conditions, he contracts as his assistant Robert Hooke that begins helping him in his expe-riences with compressed air, with physical vacuum, with respiration and with combustion. In 1660 he publishes his principal work “The Sceptical Chymist”, that made him re-nowned in Physics and Philosophy. In this work he expresses his thought about certain theories he believed to be wrong, as the one from Aristotle. By this time, together with Sir Christopher Wren (1632 to 1723), an architect and mathematician, with John Wallis (1616 to 1703) and with William Brouncker (1620 to 1684), a mathematician too, he funds “The Royal Society of London For The Promotion of Natural Knowledge”, or simply as we know until today, The Royal Society, to which after some time adheres Robert Hooke, Boyle’s assistant. Still by this time, Boyle discovers the relations between the volume of gases and the pressures to which they are submitted, and establishes the known Law of Boyle, or the

37


Law of Perfect Gases.

Fig. 1.24 Robert Boyle (1627 to 1691) This Law was rediscovered some years later by Edme Mariotte, being that the rea-son it began being called as “Law of Boyle-Mariotte”. Based on this law, Boyle explained the mechanism of respiration of animals, the man included. He publishes another book in 1664, where he explains various discoveries, among which we can find the digestion process of food, and the property presented by the Violet juice to change in color in contact with acid or alkaline solutions. The properties of Violet juice made it possible for the first time to identify acids and bases by colorimetry. Boyle was a follower of the ideas of Francis Bacon, and this influenced his tempe-rament. He made various trials to explain chemical phenomena in terms of an atomic theory. His declared dream was the emission of a corpuscular or atomic theory, with which he could explain all the chemical phenomena. He was not able to concretize this dream, but he discussed a great gamma of phe-nomena and chemical processes in atomic terms. Helped by Robert Hooke, Boyle built the first air pump (air compressor), and belie-

38


ving in the possibilities of this invention, he developed extensive researches, by means of which, besides having discovered the respiration process, as we told before, he demon-strated near every physical characteristics of the air, its need for the combustion process, and for the phenomena of sound transmission. Boyle was able to completely change the vision of chemistry as a whole. His posi-tion in the Chemistry is comparable to the position of Copernicus in Astronomy. But as in Astronomy, many years should pass for the structure of Modern Chemistry became outlined by Lavoisier and by Dalton. It is something difficult to believe, but the great truth is that till some time ago we had no notice of the existence of some portrait or engraving of Robert Hooke. And this was in a great part caused by his famous, influent and vindictive enemy and colleague, Sir Isaac Newton. On the other side, according to some biographers, this is caused too by Hooke, who never permitted his portrait to be done because according to his own words, he was “thin, crooked and too ugly”. That is the reason why we thought to be a good idea to place here a portrait of Sir Isaac Newton, for our reader to know such a great scientist, but extremely temperamental and traumatized. Moreover, Newton consumed a great part of his life in conflicts with several scien-tists like Leibnitz and Flamstead, among others, arming against all them his revenges, es-pecially against those from whom he received great collaboration to carry out his work. He abided to show that he putted in his books and publications the names of his work collaborators, as well as the names of other scientists on whose works he based, and then, in a terrible instinct of anger and revenge, took those names out of the works. He never admitted criticisms of anybody whoever they were, answering furiously to all them. Many ones believe that this personality was caused by the abandon he was submitted to, when he was a child. Though the work of Newton be of an invaluable value to mankind, especially in the one related to the Universal Gravitational Laws or even those works related to his discove-ries on Optics, we don’t find in it any relationship with Hydroponics, and that is why we will not enter in details about its life. Recently a proven true portrait of Robert Hooke was found, among several ones said true but with no proves. Robert Hooke was born in July 18, 1635 in Freshwater, in the Island of Wight in England. He attended the school at Westminster, where he learned Latin and Greek, but dif-ferently of his contemporaries, he never wrote anything in Latin, and he preferred to ex-press in English. At Oxford, the city where he knew Boyle and became his assistant, to help him in the construction of the air pump, he attended the Christ College.

39


He discovered the laws of elasticity in 1660, said laws today known as Hooke’s Laws.

Fig. 1.25 Sir Isaac Newton (1642 to 1727) He worked very much with Optics, Single Harmonic Movements, and Stresses in Helical and Spiral Springs. In 1665 he was named to the Gresham College of London, where he became a teacher of Geometry during 30 years. Hooke invented the conical pendulum, and he was the first person to build a reflex-ion gregorian telescope. He made many astronomic observations, and discovered the rotation movement of the planet Jupiter. His drawings of Mars were later used to determine the rotation cycle of that planet, and in 1666 he proposed that gravity could be measured by using a pendulum. He was a very competent architect, and with his post as a teacher, he assumed the one of inspector and surveyor of the city. In 1696, after the great fire of London, he was named the Chief Assistant of Sir Christopher Wren in the project for the rebuilding of the city. In 1672, he was trying to proof that the Earth moved in an elliptical orbit around the Sun, and six years later, to explain the movement of the planets, he proposed a law based

40


in the inverse of the squares of the distance between them. Hooke was not able to furnish the mathematical proofs of his conjectures, but he always claimed for his priority in the discovering of the law of the inverse of the squares, and this took him to his major dispute with Newton.

Fig. 1.26 Robert Hooke (1635 to 1702) This dispute reached such a point that Newton used this fact as an excuse to retire the name of Hooke from his book “Principia”. The researches and inventions of Hooke had no frontiers within science, and they were from Physics to Astronomy, from Chemistry to Biology, from Geology to Architecture and to the Naval Technology. He kept up correspondence and cooperated with scientists so diverse as Christian Huygens, Antony Van Leeuwenhoek, Christopher Wren, Robert Boyle and Isaac Newton. Among his inventions, we can cite some as the universal mechanical joint, the iris diaphragm system, a prototype of an artificial respirator, the escapement system of anchor and hair spiral spring with which we can make some of the most precision watches. He worked in the correction of the theory of combustion, he helped Robert Boyle in the development of the Law of The Perfect Gases and he worked in the Physics of The Elastic Materials. He invented and perfected various meteorological instruments as the barometer, the anemometer, the hygrometer and many others.

41


He was that kind of virtuous scientist, capable to contribute with the most important discoveries in any field of science, and do not be admired, as he made some of the great discoveries in Biology and Paleontology. His reputation as a biologist is specially based on his book “Micrographia” published in 1665, which became one of the most searched and read books not only within the scientific ambient but also out of it. For a three lenses microscope he built, based on the Huygens “lunette”, he devel-oped an incident lighting system which for his epoch was the most perfect of the world. Across his microscope he observed and studied a series of objects as diverse as insects, sponges, bryozoans, feathers, and many others from which he made detailed and precise drawings which were published in his book “Micrographia”. May be his most important microscopic observation was that of thin blades of cork, where for the first time the cells were seen. Really he observed the membranes of the cells, as cork is formed by membranes of dead cells. Nevertheless he called them “cells”, by the similarity he found between them and the cells of the religious monasteries, and he was the first person to use this name, that remains till today. We don’t want to elongate here respect the researches of Hooke on fossils, but he was the first scientist that observed them at the microscope. His work and discoveries within microscopy marked a new era in Biology and Bota-ny. If today we know all the cellular structure of plants, if we know the mechanism of the absorption of water and nutrients by the plant’s roots, if we know the structure of the leaves with their stomas and vascular system and much more, all that we ought to the re-searches and discoveries of Robert Hooke in the field of microscopy. But when we talk on the microscope, we also remember Antony Van Leeuwenhoek, with whom Robert Hooke kept a large correspondence. Leeuwenhoek was not a scientist. He was a merchant at Delft, in Holland, and came from a family of merchants. He had not fortune, he received no academic instruction, and he only spoke the Dutch idiom. This would be sufficient for him to be completely excluded of the scientific community of his epoch. But gifted of a large skill, dedication and an extraordinary curiosity, allied to a very open mind, completely free of the dogmas of his contemporaneous scientists, he got a great success making some of the greatest and most important discoveries in Biology. He discovered the bacteria, the Protozoa, the sperm cells, the cells of blood, micro-scopic nematodes, and much more. His discoveries that circulated around the world of that epoch completely opened the world of microscopy to the knowledge of the scientists. Antony Van Leeuwenhoek was Born at Delft, in Holland at October 24, 1632 and

42


died at August 30, 1723. His father was an artisan, manufacturer of baskets, and his mother came from a family of brewers.

Fig. 1.27 Antony Van Leeuwenhoek (1632 to 1723)

He was educated at a common school of Warmont, and after that he lived with his uncle at Benthuizen. In 1648 he became an apprentice in a tissue laundry. Around 1654, he returns to Delft, where li lived the rest of his life as a tissue merchant. He also worked as a surveyor, as a wine analyst as a minor official of the city. In the year 1676, he was trustee of the estate of his childhood friend, the painter Jan Vermeer. In 1668, Antony Van Leeuwenhoek learned how to polish lenses; he made very simple microscopes, and began carrying microscopic observations. Some biographers say that he only began making observations after reading the book "Micrographia" from Robert Hooke that was illustrated by the author. It is known that Leeuwenhoek built more than 500 microscopes, and from these, around ten exist until today in museums. Making a judgment by the known devices, the microscopes of Leeuwenhoek were no more the single lenses with great enlargement power, and not compound microscopes. They were formed by a simple metal plate, where the lens was placed, and it was equipped with a back screw in the vertical position.

43


This screw was placed at the back face of the lens, and it had a second screw whose function was to lock the first one. The first screw ended as a sharp needle where the sample to be observed was stuck. There was nor even a focusing system. All this mounted set was no more than 80 or 100 mm long, and to be used it had to be manually held with the lens touching the eye as if it were a monocle. Besides this, a very lighted ambient was needed for it to be used.

44

Fig. 1.28 Microscop of Antony Van Leeuwenhoek (around 1600) Many people believe that the microscope was invented by Antony Van Leeuwen-hoek, but that is not true, as that instrument was invented in 1595 by Zacharias Jansen a Dutchman from Middleburg, forty years before Leeuwenhoek was born. And the microscope invented by Jansen was yet tubular shaped, was constituted by two lenses and had a focus adjustment. We must remember here that there are many doubts about if Hooke built his micro-scope, as many people believe he bought it from Jansen, and only developed the lighting system. However, because of the technical difficulties in making lenses, the first micro-scopes had an enlargement capacity of no more than twenty or thirty times the natural size of the objects. However the particular skill of Leeuwenhoek in polishing lenses, besides his high eyesight degree and the his care with lighting choice, made it possible for him the con-struction of microscopes that could enlarge as much as two hundred times the natural size of the objects. What more distinguished Leeuwenhoek, has been his curiosity in the observation of everything he could mount under his lenses, and the detailed way he was able to describe everything he could see. As he had no ability for drawing, he contracted a draftsman to draw everything he


described not only orally but also in writing. The details of the microorganisms that he observed and that he described in writing were so thorough, that it was sufficient to read his texts for one to immediately recognize what he had observed. In 1673, Leeuwenhoek began sending letters to the recently formed Royal Society of London, describing what he was observing at his microscopes. He made that during fifty years. His letters written in Dutch, were translated to English and Latin, and printed in the "Philosophical Transactions of the Royal Society", and many times reprinted separately. His observations were so extensive and detailed, and contributed in such a way to the scientific development of that epoch, that in 1860 he was elected an integral member of The Royal Society, joining to scientists like Robert Hooke, Henry Oldenburg, Robert Boyle, Christopher Wren, and so many others, even without ever having taken part in any meeting of that eminent society. In 1698, he received at home the Czar Peter “The Great” from Russia, to whom he demonstrated the circulation in the capillaries of an eel. He continued his observations until the last day of his life, in August 30, 1723, as-sisted by the minister of the New Delft Church, who wrote to the Royal Society: “Antony Van Leeuwenhoek considered that what is truth in Natural Philosophy can be investigated with better results by the experimental method supported by the evidence of the senses; for that reason, with diligence and tireless work, he made his lenses, and with its help, he discovered many secrets of Nature that now are known and famous across all the philosophic world”. Today, those that are or pretend to be hydroponicists or researchers in that field, can take a microscope and identify the contamination of his plants with a nematode or with some kind of fungus. Or using the same facility, they calibrate their time controller to ad-just the best irrigation cycle or the fogging cycle of their plants. They can do that because there were scientists like Robert Hooke, curious, devoted and persistent, or like Antony Van Leeuwenhoek, that despite his “ignorance”, he reached to the borders of science, showing to men of their epochs the world that was unknown to them, and many times relegated to lower planes by their leaders. And as things frequently happen, the great impulse towards the way that would fi-nally conduct us to the hydroponics technique, comes from a personality dismissed of the great scientific knowledge acquired in the universities. We are speaking about Sir John Woodward, the man who in fact was the Great Ini-tial Milestone of Hydroponics. He was born at Derbyshire, in England, in May 1, 1665 and died in a not precise day in April, 1728. There is a citation in one of his letters that makes us suppose that his birthday has been in the year 1668. He attended no one university; however he had a great domain of Latin and good knowledge of Greek, idioms he learned in the interior of the country.

45


Fig. 1.29 John Woodward (1665 to 1728) He learned practical medicine as an apprentice of Peter Barwick, the physician of the king, between 1684 and 1688. He got his “Master Doctorate” as a special award given by the Canterbury Archbi-shop in 1695, with the Lambeth degree, and this was confirmed by Cambridge in 1697. But it is not certainly known in what profession or university degree he was doctorate. He deeply dedicated his work to Natural History, Geology, Paleontology, Botany and to Medicine. The interest of Woodward by science was very diverse, and during his journeys practicing Medicine which he began very young, he deeply studied the plants, the minerals and the fossils. His reputation began when he presented as essay entitled "Essay Towards a Natu-ral History of the Earth" which was a very advanced theory to explain the soil stratification with the fossils incrusted in them, starting on the residues deposited in it derived from hailstorms or floods.

46


He insisted that the fossils were animals and plants residues which lived in past eras, relating those fossils with the formation of rocks. He formed a great collection of fossils and minerals that he collected personally or that were sent to him from several places, which he tried to classify, according to his book "Naturalis Historia Telluris", published in 1714. This way he reached to his first classification of minerals, even too primary, in his book "Fossils of All Kinds Digested Into a Method" published in 1729. In this book for the first time it was used the term “fossil”, that it is believed to be created by Woodward. In a work of posthumous publication in 1729, he also took care of minerals, having too written a treatise on natural history of ores and metals, which as we told before, was not published during his life. Based on all this work, he was considered as being the greatest personality of Eng-lish Geology. He was too temperamental, arrogant, sensible and quarrelsome, and all this granted him innumerable enmities, but even so, in 1693 he was elected as a member of The Royal Society, where for various times he integrated the administration council, and he was elected too as a member of the Medical College and of the Royal College of Phy-sicians, in 1703. On medicine he only published a work, "The State of Physics and of Diseases", in 1718, which provided him various discussions and fights, which were frequent in his life. Dr. Peter Barwick, the physician of the king and his instructor of medicine, as well as Robert Plot, one of his few friends, influenced his appointment as a teacher of the Gresham College, where he taught between 1692 and 1728. Woodward left as a legacy to the Cambridge University, two cabinets with fossil col-lections to be used as teaching material, besides a good sum of money to be used after his death in the foundation of the "Woodwardian Professorship of Geology". In 1729, the University bought the remainder of the collection from Woodward’s as-sets, funding the Woodwardian Museum, with didactic finality, used and maintained by the Woodwardian teachers. As a tribute to Adam Sedgwick, a Woodwardian teacher, it was built the actual Sedgwick Museum of Geology, in Cambridge, where we can find the fossils collection of John Woodward. But his life as a systemic experimenter on plant nutrition is the more interesting part for us. John Woodward believed that fundamentally plants feed on water and not on soil. But when he removed plants from soil and left those to survive with the roots immersed in water, they died in a short time period. He noted that really plants absorbed water, because he had to replenish it in the glass pots where he kept them. However when he kept the water level under the crown of the roots, its life was

47


longer, and for that reason he began keeping around half of the roots immersed in it. To-day we know that plants absorb the greatest part of Oxygen by the bodies of the roots, and not by their tips. He verified too that the plants he maintained in pots with soil had a greater life if said soil was periodically irrigated. No results were obtained by irrigating the leaves. Then he asked himself what relationship could exist among the plants, the soil and the water. So he took the final decision, and dissolved soil in water, letting to settle the non dissolved part of it. In the obtained solution he suspended mint plants, and then he verified that they survived and developed. He experienced other kinds of plants and several kinds of soil, and the results were always positive. However when he used soils that came from places of cattle or bird trampling, many times his plants died. So he began dosing the quantities of dissolved soil according to its origin, and he verified that it was needed to adjust the quantity of soil in the solution, considering the ori-gin of said soil. When he began writing his conclusions he said: “Plants feed on water and on elements found on soil dissolved in it. When we can find which elements are those, we can dispense soil to cultivate them. There is a process in each part of nature that is perfectly regular and geometric, and once we are able to find it, we will receive the compensation of our work. I believe that I discovered one of those processes and I am sure that sooner or later Nature will reward us”. John Woodward could never imagine that he just started the modern Hydroponic Technology. For our everyday, there is no doubt that it is easier to say “lettuce”, “tomato” or “man” than to say "Laetuca Sativa", "Lycopersicum Esculentum" or "Homo Sapiens" that are words in Latin. As if that were not enough, to each pair of words in Latin, in the majority of cases we join letters as “Lin” or “Linn”. But as an example if we are in Portugal or Brazil, and we want to buy some lettuce seeds, once we have domain of the idiom we just say “Sementes de Alface”. But if we have not the domain of the idiom, it will be sufficient to say "Laetuca Sati-va" Seeds. This happens because all living beings today are classified in a determinate order, according to certain characteristics that are peculiar to each one. And to each living being a name was given. As since ancient times Latin was con-

48


sidered the universal language, the name was given in that language, as for that name could be recognized by any person, speaking any idiom. And what are those letters at the final of each name? Well, they generally are ho-mage to who for the first time classified that being, or to some famous personage within the scientific world. In our example, “Lin” or “Linn” are homage to Linnaeus, or better, Carl Linnaeus. As we have showed various times along of these pages, since the epoch of Theophrastus various scientists and researchers have dedicated several years of their lives in an attempt to establish a classification to the living beings. The various classification attempts, with a better or with a worse success along the centuries, always had two basic aspects orienting them. The natural classifications that considered not only the living being but also the am-bient where it developed, or the purpose for which it was intended. The artificial classifications that grouped the living beings according to peculiarities common to all the participants of each group, as for example, the kind of flower or the kind of leave of a determinate group of plants, without considering its “habitat” or their utility. Theophrastus formulated an artificial classification, and the same was made by Andréa Cesalpino and other ones. But Dioscorides used a natural classification as be-sides the morphologic characteristics of plants, he considered too their “habitat” and their utility. However, the most perfect classification of living beings begun by the classification of plants made by Carl Linnaeus. There is no direct connection between the History of Hydroponics and the classifica-tion of living beings, and we believe that nor does an indirect connection exist. The only relationship concerns to plants in general. But in these pages we have extended our topics related to the History of Hydropon-ics adding small biographies of the personages that we believe to be connected to it, even that connection resumes to very small evidences. We have added too some clarifications to certain doubts that remain until today as is the case of the Suspended Gardens of Babylon. So, why should we not speak about a personage that was able to join all the world scientists tied to the science of life in Nature, be them from yesterday, from today or from tomorrow? We say that he joined because all those, from a certain date on, began using the living being classification system, be them yet known or that someday will be known, idea-lized by that scientist. So, let us peak something about him. Carl Linnaeus, as is his baptismal name, was born in Sweden, in Stenbrohult, in the province of Smaland, at May 23, 1797, and died victim of a brain hemorrhage in 1778. In his books, Linnaeus used his first name in a transformation to Latin, Carolus, keeping his surname.

49


50

Fig. 1.30 Carl Linnaeus (1707 to 1778) In 1762, he was knighted and received the noble title from King Adolf Frederik, when his name changed to Carl Von Linné. The “Von” was added to his name to give him the mark of German nobleness as such a mark does not exist in Swedish language. Dur-ing this change of name endowed with a mark of nobility the last letter of Linné received the acute accent. Thus, when we find citations as Linnaeus or Linné, or even Carolus or Carl, all them are correct, though the most correct of all them is Carl Linnaeus, his baptismal name. His father, Nils Ingemarsson Linnaeus was a professional gardener, and a Lutheran minister, whyle Carl, since he was a child, showed a profund love for the plants, greatly disappointing his father as he presented no interest for priesthood. However he gave a great joy to his family, when in 1727 he entered the Lund Uni-versity to study Medicine. This way, a year latter he transferred to the University of Upp-sala, the most prestigious university in Sweden. Nevertheless he had no interest in the medical course he was attending, taking advantage of it only for the Botany classes, and spending the greatest part of his time col-lecting and studying plants.


We must understand that by that epoch the medical courses were very complete in terms of Botany, as the medical therapies were essentially phytotherapeutic, and the phy-sicians prepared themselves the drugs they prescribed. In 1731, though under terrible financial conditions, Carl mounted an expedition on Botany to Lapland (in the portrait of Linnaeus we show here, he is using a typical Lappish costume). Even in 1731, he mounted another expedition for botanical researches to the Central Sweden. In 1735, he goes to Holland, where, in the University of Harderwijk he concludes his course in Medicine, and after that he concludes his postgraduation in the University of Lei-den. In the same year he published the first edition of his book "Systema Naturae", where he presents his living beings classification system, then keeping contact or corres-pondence with the greatest botanists of Europe, and continues perfectioning his classifica-tion system. He returns to Sweden in 1738, where he began to practice medicine, and in 1741 he was named a teacher at the University of Uppsala. Here he restores the Botany Garden of the University, distributing the plants of the garden according to his classification system, inspiring all a generation of students in his love by the same. He continues improving his classification system of beings yet described in "Syste-ma Naturae", and he still finds sufficient time to practice medicine, becoming the physician of the Swedish Royal Family. The last years of his life were marked by an incredible depression, passing away, as we told before, in 1778, victim of a brain hemorrhage. His classification system was binomial, that is to say, each being receives a name composed of two words, being the first one the name of the gender of the being, and the second one, the name of the specie. The sequence of his classification was constituted of Kingdoms, Classes, Genera and Species, and within it, he classified more than four thousand living beings, included the Man that he called Hommo Sapiens, and he was the first one who did that. Always looking to the classification of living beings, Linnaseus wrote various works as “Flora Lapponica” in 1737, a result of his expedition to Lapland in 1731, "Philosophia Botanica" in 1751, "Species Plantarum" in 1753, and "Genera Morbum" in 1763. Much could be talked about Carl Linnaeus, but for that, we would exaggeratedly escape from the goal of our work. Besides that, during the period when he was dedicated to the classification of living beings, the Chemistry Science continued advancing more and more, with great discove-ries of an enormous importance to the knowledge of Plant Nutrition, and at the same time, to the development of Hydroponics. John Woodward had yet delineated the basic principles of water culture, but when he emitted his conclusions, he didn’t know the mechanism of the absorption of carbonic gas by the plants by means of their leaves. He nor even knew the Carbon Dioxide.

51


Fig. 1.31 Joseph Priestley (1733 to 1804) And this knowledge came to us by the discoveries of Joseph Priestley. One of the six sons of Jonas Priestley, Joseph Priestley was born at March 13, 1733, in England, at Fieldhead, near Birstall, in Yorkshire. His mother died during the confinement of his sixth son, in six marriage years.

Still young he decided to follow the career of priesthood, and for that he studied Lat-in, Greek and Hebrew.

As a victim of a lung disease, which left some doubts if he could or not continue the career he decided to embrace, he learned by himself the French, Italian and German lan-guages, this way getting prepared for a commercial career. However his health has recovered and he entered the Daventry Academy, being graduated as a Church Minister in 1755. In 1758 he changed his residence to Namtwich, then becoming a teacher at the Warrington Academy at Lancashire, from where he re-ceived his final ordination to the priesthood in 1762.

In the same year he got married with Mary Wilkinson, the only sister of a cutler.

In Nantwich, he began teaching Physics and Chemistry, and in a visit to London in 1766, he knew Benjamin Franklin, who gave him various books. When he knew that Priestley discovered that charcoal was an electrical conductor, he asked him to edit his book "History of Electricity", that Benjamin had recently written. During all his life Priestley divided himself between the priesthood and science, to

52


which since his youth he showed he had a great vocation. When he was nine years old, Priestley was adopted by his aunt Sarah Keighley, who as his husband was a “Dissenter”. The “dissenters” were people that belonged to other churches other than the Eng-lish Church, and in this group were included the Catholics, the Quackers, the Calvinists, the Presbiterians and others. Priestley was a Presbiterian. Because of this religious dissidence Joseph Priestley was forced to migrate to America in April 8, 1794, where he fixed residence at Northumberland, near Philadelphia, where he died in February 6, 1804 victim of pleurisy. The religious career of Priestley was very turbulent, and to some extent impaired him during all his life, but here we will be more dedicated to his scientific career. In 1766 he was admitted to the Royal Society. In 1772 he was elected member of the French Academy for Science, and in 1780 he was named member of the Saint Peters-burg Academy in Russia. For financial reasons, in 1767 he became a minister in Yorkshire, in the congrega-tion of Mill Hill, at Leeds. And here his interest by the study of gases really begins, which made him famous in the world of science. At Leeds, Priestley lived near a brewery, and there he discovered a way to collect the gas exhaling from the beer fermentation tanks, verifying afterwords that this gas dis-solved in water and other liquids. He thought that by dissolving this gas in wine, he could make gaseous wine as beer, and he suggested that this wine could prevent the scurvy in sailors in long sea jour-neys. Really he had discovered the Carbon Dioxide, and by the fact of dissolving it in wine, we can say that he became the father of gaseous beverages. Priestley achieved the isolation of several gases, as Nitrogen Oxide, Amonium Gas, Sulfur Dioxide, Carbon Monoxide and Carbon Dioxide, and for that he used a Mercury pneumatic cuba (hidragiropneumatic cuba or chamber). Before we go on, we must remember that he was favor of the theory of the “Phlogis-tum”, preserving this position even after personally knowing Antoine de Lavoisier, and hav-ing changed with him many ideas and opinions respect this in various meetings, besides a lot of correspondence. He studied with detail every gas he discovered and isolated, always looking for a practical use for them. In cooperation with Henry Cavendish he discovered that water is a compost formed by Oxygen and Hydrogen. However the greatest discovery of Joseph Priestley was the Oxygen that he iso-lated from Mercury Oxide, in August, 1774. We must make here a reservation about the discovery of Oxygen by Priestley.

53


Though we learn and read everywhere of this discovery of Priestley, really the Oxy-gen was discovered in 1772 by the Pharmacologist Karl Wilhelm Scheele. But the work of Scheele was published and given to the knowledge of the scientific world only in 1777, and for that reason Priestley didn’t know it. However, Priestley published his discoveries in his book “Experiments and Obser-vations on Different Kinds of Air” in 1775, two years before Scheele. That’s why we give to Priestley the privilege of that discovery. From the many experiences made by Priestley, the one which became very exten-sive and valuable to us was the one referent to Carbon Dioxide. As was his habit, our scientist always looked into the practical applications for the gases he discovered, and he noticed that when he placed a mouse inside a glass bell full of Oxygen, the animal died in a short space of time. He concluded that the animal consumed the Oxygen of the bell, and verified that the resultant gas inside it was carbon dioxide. So he reached the conclusion that Oxygen was fundamental for respiration and survival of animals, besides that by respiration they exhaled carbon dioxide. On the other side, in the experiences with carbon dioxide, as he knew a mouse could not survive in a bell with that gas, he tried a plant. To keep the plant alive inside the Bell, he placed it in a soil solution as it was yet been experimented by John Woodward, and in the same way, he used mint plants. He verified that the plants survived during a certain time and then they died. He made an analysis of the residual gas inside the bell, and verified that it was Oxygen. He knew the composition of carbon dioxide, and concluded that in a certain form the plants consumed the carbon of carbon dioxide, and left in its place or exhaled the Oxygen. Analyzing the results of his experiences, he concluded that if the plant needed car-bon dioxide to survive and the mouse needed Oxygen, by joining a plant and a mouse in-side a same bell, he could compensate the formed and the consumed gases. He experimented that, and the result was positive. Without pretending it, he had verified the absorption of carbon existing in carbon dioxide of air by the plants, and the liberation of Oxygen by these ones. At the same time, without pretending it, he confirmed the experiences of John Woodward relative to the survival of plants in a soil aqueous solution. With these experiments, latter, we could explain another part of the weight differ-ences found by Jan Van Helmont. The large weight increase of his willow seedling came not only from water, but also from the Carbon of the carbon dioxide existing in air. In summary, he discovered the respiration system of plants, that today we know as photosynthesis, but he didn’t discover its mechanism. Joseph Priestley known by his calmness, his amorous way on speaking even when he was preaching in public, was able to conciliate religion with science, never mixing them,

54


and was recognized as one of the greatest scientist precursors of the modern Chemistry. By his “status” of chemist and religious man, he made us understand the impor-tance of vegetables in nature when he said: "I have been so happy as by accident to hit upon a method of restoring air which has been injuried by the burning of candles and to have discovered at least one of the res-toratives which Nature employs for this purpose. It is vegetation". One of the characteristics of Priestley, which to a certain extent damaged him too much, was that he reported not only his successes but also the failures of his experien-cies. Thus we know that not always he succeeded when he placed plants under carbon dioxide to obtain Oxygen. When he carried his experiments under dark or cloudy days his results were negative. He never discovered the “why” of this phenomenon and only in 1779 the Dutch Physiologist Jan Ingenhousz (1730 to 1799), by the publication of his book “Experiments on Vegetables” the solution of this problem came to light. By repeating the experiences of Priestley, Ingenhoulsz verified that for the pheno-menon to happen it was needed that the plants were exposed to sunlight. He discovered too that only the green parts of the plants had the capacity to pro-duce Oxygen. Besides that, he verified that there was a direct relation between light intensity and the production of Oxygen, or better, the largest the light intensity, the largest quantity of Oxygen produced. Slowly, by means of years of researches, the scientists revealed the “whys” of the differences of weight encountered by Jan Van Helmont in his experiment. And another step was given by the Swiss Physiologist, Nicholas Theodore de Saussure (1767 to 1845). Son of the scientist, geologist philosopher and alpinist Horace Benedict de Saus-sure (1740 to 1799), he was born at Genève in Switzerland. His father decided to educate him, and carried him in several scientific expeditions. He was a member of the expedition his father made to the Mont Blanc in the Swiss Alps in August 3, 1787, and carried a series of experiences that confirmed the work of Edmé Mariotte about the weight of air at different altitudes. It is interesting to note that Horace Benedict de Saussure was the second man to climb the Mont Blanc, one year after the first climbing carried out by L. Balmat and M. G. Paccard. During the climbing of the Mont Blanc he made several experiments about the hu-midity, air pressure and water boiling, and besides this, he estimated the height of this mountain as being 4775 meters, a value 30 meter less than its real height. He developed his interest by Botany, especially plants Physiology, during his alpine

55


expeditions and in 1797 he published various works about the formation of carbonic acid in plants.

Fig. 1.32 Jan Ingenhousz (1730 to 1799) In 1802 he was named teacher of Mineralogy and Geology in Genève. Though keeping this position, he never made a talk or lecture, because he really wanted a position in the field of Chemistry of Plants. He always continued his researches in Botany, and in 1804 he wrote the book “Re-cherches Chimiques Sur La Vegetation”. His most important work was in the Field of photosynthesis. Still in 1804, he dem-onstrated that plants gain weight converting carbon dioxide into Oxygen and Carbon. Originally he correctly concluded that this reaction is light dependant, and incorrect-ly he concluded that Carbon and Oxygen were products formed from carbon dioxide, and not always this is true. However he verified “a posteriori” that there was a weight gain in plats larger than that due to Carbon, deducing then that water could be incorporated to the weight of the plants. Repeating the experiment of Van Helmont, after 200 years, now provided with better laboratorial facilities and armed with the knowledge of actual Chemistry, for his epoch, he correctly measured the participant weights of the different parts. This way, in 1804 he confirmed that water was an integrant part of the process of Oxygen production that it is absorbed by the roots, and transpires by the leaves.

56


Fig. 1.33 Nicholas Theodore de Saussure (1767 to 1845).

Besides this, he discovered that the green color of the leaves and some other parts of the plants was caused by a substance that was named as “chlorophyll”, this one being responsible for the absorption of light, and for the transformation of carbon dioxide into Carbon and Oxygen, a phenomenon denominated as “photosynthesis”. He still verified that respiration is needed to the growing of plants, and that a great part of the solid mass of them comes from air, and not from soil. From the elements then known, de Saussure elaborated a list of nine of them found in plants. And so, the doubts referents to loss of weights in the experiment of Van Helmont were enlightened. Till today photosynthesis is a process extremely studied, and at the moment, we know about 50 reactions that compose it, regulated by enzymes. Other composts similar to chlorophyll have yet been determined, that act secondari-ly to it, be it together or in different phases of the cycle of the plants. As we can see once more, the knowledge on Plant Nutrition developed slowly and together to those of Chemistry, and in the research processes, the involved living plants inside laboratories were maintained alive in “soil solutions”. And as we have seen before, more than once various discoveries, be them tied to Chemistry or not, influenced in the ways of Hydroponics throughout its history.

57


Perhaps this was the case of the isolation of various chemical elements, example of which would be the Sodium, the Potassium the Calcium and many others. There is no doubt they were elements yet known, but as many others, in a pure state, in the majority of cases that was a dream. In its greatest part, the pure chemical elements known were those found in nature in that condition, as Sulfur and Mercury. Priestley awarded us with the Discovery of Oxygen and some other elements, but even those could be found in nature. He only discovered and isolated them. And it is in this phase of our history that comes to us Humphry Davy, also known by many people as Humphrey Davy. We can’t affirm if by his baptism his correct name was Humphry or Humphrey, but in his writings he always signed Humphry, and that is why we adopt here this name. Humphry Davy was born in England at December 17, 1778, at Penzance in Corn-wall, and his school education happened not only at Penzence but also at Truro. By the death of his father in 1794, he was forced to work to help in the supporting of his family, and he did it as an apprentice of the surgeon and pharmacologist J. Binghan Borlase. Under the influence of the reading of the book “Traité Elementaire” from Antoine de Lavoisier, since 1798, Davy became very interested in Chemistry, and advised by his friend Cavies Giddy, he got courage to begin his studies on Chemistry. Thus he dedicated very hard to the studies of various controversies about the Che-mistry of his epoch, besides Optics, Physics and the Nature of Electricity. This provoked a great interest in him by Thomas Beddoes, who recommended him to the Pneumatic Institution of Bristol, an organization dedicated to the study of the clinical applications of various gases. And here began his reputation. He studied the various Nitrogen Oxides, and dis-covered the physiologic effects of the Nitrous Oxide, very known as “Hilarious Gas”. And this way, in 1800 he publishes his work “Researches, Chemical and Philosoph-ical”, where he describes the effects of various gases as carbon monoxide obtained by the production of the gas of water, whose inhalation almost killed him. In this work he includes his discoveries of the analgesic and anesthetic effect of the hilarious gas recommending it for use in the reduction of pains during surgeries. This earned him the appointment as a lecturer at the recently founded Royal Institution of Great Britain. He was graduated as a chemistry teacher in 1802, and as a consequence of his lectures and experiments, he was named a member of the Royal Society, where he was named secretary during 1807. In 1802, in cooperation with Thomas Wedgewood, Davy published the work "An Account of a Method of Copying Paintings on Glass, and Making Profiles, by the Agency of Light Upon Nitrates of Silver".

58


Fig. 1.34 Humphry Davy (1778 to 1829) Davy produced the first photos using glass plates recovered with Silver Nitrate, but the images were temporary, becoming completely black once separated from the negative and in contact with light. Since the Discovery of the electric cell by Volta, in 1800, which caused a real storm in the scientific world, Davy became interested for its study, trying to explain how it worked, and trying to develop it in practical applications. Between 1806 and 1807, he presented the most developed researches on the cell, as well as his theories of “Electrochemistry”, a term he created. However his most important discovery was the chemical elements Sodium and Po-tassium, obtained by the electrolysis of melted Sodium Hydroxide and Potassium Hydrox-ide, using for that a cell with 600 elements. As told by his brother, Dr. John Davy, when Davy saw the small and brilliant gra-nules of Potassium appearing in the negative pole of his electrolytic cell, he began danc-ing, singing and jumping around his laboratory. After this he built the largest electric cell of the world, in that epoch, with 2,000 ele-ments, with which he began feeding his electrolytic cell and denominated the process of electrolytic decomposition as “Electrolysis”. Then he discovers the Calcium, the Barium, the S. trontium, the Iodine and the Bo-ron, and in the same way he named other elements he discovered, he named these ones too. In the same epoch he discovered that the diamond is an allotropic form of Carbon.

59


The result of his experiments to obtain these elements as well as the continuation of his researches, were described in his work "On Some Chemical Agencies of Electricity", and in 1806 he received the “Napoleon Prize”, awarded by the “Institut France”, valued at 3,000 francs. This was an unusual international honor, as by that time France and England were at war. In 1812 he got married with Jane Apreece, a young and rich widow. In 1813 he contracted as his assistant the young Michael Faraday who would become one of the most famous scientists of the next generation. Many historians say that Faraday was the greatest discovery of Davy. In 1818, he received the title of “baronet”, and from then on he came to be called Sir Humphry Davy. Then he resigns the Royal Institution, and begins a travel through Europe, in the company of his wife and his assistant, including to France, where to enter and travel, he received a personal authorization given him in hands by Napoleon. He always traveled with his portable laboratory, and made various contacts in the ambient of the Continental Europe, where he realizes important works with Chlorine. The Chlorine had yet been identified and separated by Carl Wilhelm Scheele in 1774 and this scientist identified it as “marine dephlogisticated acid” and the same was known in England as “oximuriatic acid”. Davy discovered that this “acid” was an element, and baptismed it as Chlorine. He discovered too that reacting it with Amonium, the result was a gaseous compost formed by Chlorine, Hydrogen and pure Nitrogen. This way he discovered the hydrochloric acid or muriatic acid, and this way too he put down the theory of Antoine de Lavoisier who said that Oxygen was the essential com-ponent and characterizer of the acids. In summary, he proved that it is Hydrogen that characterizes acids, and not the Oxygen. He too dedicated himself to the theories of combustion and to the study of the flame, and in 1815 Davy invented the famous “Security Lamp” to be used in the coal mines, where he used the theory of metal screens with tight meshes. This lamp, as all them in that time, was a flame lamp, could be used in the coal mines, generally full of mixes of air and methane gas, called colliery, highly explosive. He never patented his invention, and this was an error as it gave margin for the railway engineer George Stephenson to get credit to that invention. However not even Stephenson patented it. Inquired about to get or not the patent Davy said: “No my friends, I’ve never thought in such a thing. My only objective was to serve the cause of mankind, and if that succeeds, I will be highly prized and rewarded by having done it”. Davy discovered and named the element Aluminum, a name till today used in coun-

60


tries where the British idiom is spoken. In the other parts of the world it is used the term “Aluminium”. He invented too the voltaic arc lamp, and developed and developed too a process to desalinise sea water. He was too the initiator of the galvanoplastic processes, when he developed the plating of pieces of Copper with Zinc, via the electrolytic system. He still published a book integrally dedicated to agriculture, where he introduced Chemistry in soil fertilization, in leather tanning, and in the mining industry. During all his life he was a poet, but he never published his poems book. In 1827 he became very sick, and latter, this was attributed to his abuse in the inha-lation of many gases during all his life. In 1829 he fixed his residence at Rome, in Italy where he suffered a heart attack. He died in May 29, 1829, at Genève, in Switzerland. The science of Humphry Davy was motivated by problems related to life, to matter, to God, to thought, and immortality. He firmly believed that the principal finality of the existence of the human being, was the achievement of his intellect, and this way to penetrate in the secretes of the Universe of God. May be this way of thinking showed that Davy felt himself uncommonly advanced in the scale of existence. He showed that the human being, even without knowing it, is a researcher for excel-lence, a typical and fundamental characteristic of those who are or that pretend to become hydroponicists, to whom probably in a next future will be given the responsibility of feeding the living beings. He left us as a legacy, examples of personal disinterest in everything he made, be-sides his great knowledge of Chemistry that permits us today to prepare an aqueous nu-trient solution that permits us the feeding of plants that will serve to us as food, or better, to practice Hydroponics. Although the principles of hydroponics already started to take shape, even as a laboratorial practice, during the years of 1800 and even in great part of the 1900, as a result of millennia of usage, to fertilize the soil with organic residues was the most conventional practice for one to get better and greater crops. Even the chemicals of those epochs fully believed that by the “Principle of Vegeta-tion”, the essential nutrients needed for the development of plants should be of organic nature, and not mineral. And these principles were strictly kept, though the chemists, the botanists and the plant physiologists had an ample knowledge that a great part of the elements constituting the plants were mineral. It is convenient to know that the knowledge of Organic Chemistry by those epochs war relatively small, and because of that, the organic part of the constitution of plants was

61


greatly unknown. Still today, that organic constitution is subject of great researches. However the dedicated work of the plant physiologists never stopped, not only those carried by the masters of Science, but also the ones achieved by those attained to the experimental work. This is the case of Jean-Baptiste Joseph Dieudonné Boussigault (1802 to 1887), or Jean Boussingault, as he is commonly known. Jean-Baptiste Boussingault was born in Paris at February 2, 1802, and in this same city in May 11, 1887, he decided to be a chemical, mineralogist and agronomist of France. Son of an old soldier that had a tobacco shop and was the Burgomaster of Wetzlar, unable to support the Napoleonic Lyceums he graduated as an autodidact attending the public courses of the “Collège de France” and of the “Museum”. Since its foundation, he attended the “École des Mineurs de Saint-Étienne” (actual École Nationale Superiéure des Mines de Saint Étienne), where he knew Benoît Fourney-ron, with whom he discovered the quality of the Chemistry of that institution. The director of that school, Louis-Antoine Beaunier, excited for his scientific capaci-ty, entrusts him a series of experiments, and within them, he demonstrates that high quality steel must contain Silicon in its composition. By that time, Simón Bolivar wanted to found in Colombia an establishment for the formation of engineers, and received from the part of Alexander Von Humbolt the recom-mendation of Boussingault. Thus he goes to South America in 1821, he meets Bolivar in Bogota in May, 1822, and he is immediately named for his Army Staff. Very rapidly he begins a series of scientific observations, whose result is concre-tized with his appointment, in 1827, to manage an English Company for the exploration of gold. Nevertheless he always continued his scientific researches, not only in Colombia but also in Venezuela and Ecuador, said researches prolonged for more than ten years. In South America he lived an epoch of revolutionary turbulences, and he took part on several war actions, by which, inside Simón Bolivar’s army he reached the rank of Co-lonel. In Venezuela he studied various fountains of thermal water, he collected samples of rocks and minerals and he described the first new mineral species for that country, the Gaylussita. Besides that, he realized several Barometric and Botanical observations. Once back to France, in 1839 he is elected for the “Academie Des Sciences” and just after that he was named Chair Professor of Rural Economics at the “Conservatoire National Des Arts Et Métiers”, being that subject matter especially created for him. By his marriage with an Alsatian, he becomes part-owner of Bechelbronne Domain, and this enables him the dedication to experiments in agriculture, which results make him the founder of the Modern Chemical Agriculture. He became famous by his discoveries about Nitrogen absorption by plants.

62


With the cooperation of Dumas, he made researches on atmospheric air composi-tion, on the composition of vegetables, on herbivorous feeding and on the detection of Ar-senic. His book “L”Économie Rurale” became sensational in 1843 and establishes him as the first agricultural chemist in the world of that epoch. Between 1860 and 1891 he publishes a series of works under the title “Agronomie, Chimie Agricole Et Physiologie” that were rapidly translated to English and German. On his studies about Agriculture Chemistry, he used plants cultivated in aqueous soil solutions and some others of well determined composition. To make easier his work in the lifting the plants he tried to anchor them in inert sub-strates as sand, quarts granules and charcoal, keeping the roots constantly moistened with the nutrient solution, and he succeeded with this practice. This practice was the predecessor of the Substrate Hydroponic System, which many years later would be used by Dr. William Frederick Gericke. He confirmed that water is essential to the development of plants, as they retire from it Hydrogen and Oxygen. Analysing the dry matter of plants, he verified that they are essentially constituted by Oxygen, Hydrogen and Carbon, as well as other mineral elements that come from soil, dissolved in the water he used. In constant analysis of the dry matter of plants, he determined which mineral ele-ments were found in them and under which proportion they are found in the various phas-es of their development. Then, he began preparing his nutrient solution, and correcting it according the needs of the plants, to optimize their development. He was a great researcher in the use of the “guanos” originated from South Ameri-ca, and proved that the most adequate form to supply Nitrogen to the plants were the Ni-trates. He deeply studied soil organic fertilization, till then the only used, as a consequence of the rigid concept of “Principle of Vegetation”, and verified that the guanos allied to the composted organic residues, were a high value fertilizer, once they were essentially con-stituted of nitrates. Though we have reached to great vegetable productions with traditional fertilization, the sources of those fertilizers were relatively scarce, and in that epoch, there was yet a preoccupation in the production of food, as a function of population growing in the more civilized world. This system was rapidly spread by the world, and began being used in all the fields of the scientific experimental research. He dedicated himself to the hard study of Organic Chemistry, developing a system and equipment that permitted the analyses of organic products 40 times more rapid than the systems known by that time.

63


Fig. 1.35 Justus Von Liebig (1802 to 1873) As a consequence of his work till today Liebig is known as the Father of Organic Chemistry, and was considered the greatest chemical of that epoch. He issued the theory of radicals (together with Friedrich Woehler a teacher of Che-mistry of the University of Berlin and after in the University of Goettingen), and discovered the isomery and polyvalence of the chemical elements. His greatest work was dedicated to the agricultural chemistry, and in 1840 he pub-lished his work Agrikulturchemie (Agricultural Chemistry), where he describes his works on the application of organic chemistry on agriculture and in vegetables physiology. He developed all a work about plant nutrition and soil fertility, dethroning the theory of the “Principle of Vegetation” and the “Humus Theory”, besides that he proved the need of plants for mineral elements absorbed from soil, Carbon from Carbon Dioxide and Oxy-gen and Hydrogen from water. Even so Liebig believed that plants absorb Nitrogen from air, which till a certain extent is true for some leguminous plants. He didn’t know that Nitrogen fixation from air is made by means of certain bacteria in soil. Then he issued the “Law of Minimum”, that establishes that agriculture production is proportional to the quantity of the more limiting nutrient, whatever it is. By this Law we conclude that if we furnish to the soil the deficient nutrient, we raise the production of determinate plantation to the maximum said soil can produce, till the point that another nutrient becomes deficient, and then we apply the same law to this last nutrient.

64


As a consequence of this, Liebig formulated and produced the first composed chemical fertilizers, as well as he developed several processes for the production of their components. Justus Von Liebig was really the “Father of the Organic Chemistry”, and he has re-volutionized the chemical knowledge in the world. He was the founder of the processes of soil fertilization we use till today. And during his life, he emitted the basic principles for recycling agricultural residues, creating then what we call till today, the “Alternative Agriculture”. In his honor, after the World War II, it was given his name to the University of Gies-sen, which today is called Liebig University, and in 1955, the ex-president of Germany, Prof. Theodor Heuss, speaking about Liebig, said: “There is no other person that gave to do many other the possibility of living”. In the Liebig University, at the building where Justus worked, it was mounted the Liebig Museum, where the furniture and equipment shown are the originals used by this scientist. His working rooms were also kept intact. In his honor too, and for the value he has played in organic chemistry, his glass ap-paratus with five spheres used for the analysis of organic composts, the so called "Kaliap-parat", has been incorporated to the coat of arms of the "American Chemical Society". Today we can easily fertilize soils with correctly formulated fertilizes. We can easily and with a certain speed analyse the organic composts that compose a plant. We can carry correct soil analysis, and based on them we can correct the nutrient deficiencies ac-cording to the cultivation we plan to plant. We still can formulate a nutrient solution for Hydroponics, perfectly equilibrated for it to produce the effects we desire for our crops. All this is due to Justus Von Liebig, dead at Munich, in Germany, in April, 1873. Hydroponics has many debts with him, and as so many other scientists, Liebig is part of its History. The work and the discoveries of Liebig affected in a very deep way a great number of scientists. Whyle Liebig was dedicated to his work with the scope of agricultural chemistry, in 1856, Salm Horsmar was developing a parallel work. He searched for a development and improvement on the technology of plant growing in inert substrates moistened with nutrient solutions yet verified by some scien-tists, one of them and the first, was Boussingault. This way, he perfected the compositions of nutrient solutions, now always using mineral salts yet available. In the same way he developed simple and efficient systems to fix the plants that allowed him to recede, eliminating the inert substrates, and carrying his cultivations exclu-sively in water with the nutrients added to it. Though Liebig used cultures in aqueous nutrient solutions in many of his re-

65


searches, he never reached, or perhaps he has never been dedicated to a more profund work about them, may be a reason why he never published something respect to this.

66

Fig. 1.36 Laboratory of Analytical Chemistry and Physiology of Justus von Liebig (Liebig Museum - Giessen - Germany) And be it by the work of Boussingault, be it by the one of Salm Hosmar, a well de-fined way to the culture of plants in nutrient solutions was being delineated, though every-thing showed that such cultures would be restricted to laboratorial levels, as till a certain extent they made easier the work of scientists, especially of those dedicated to the study of plant nutrition. There were however a series of doubts about the chemical composition of such so-lutions that apparently needed a certain monitoring, as their behavior was different of that in soil, where normally there was always an exceeding of nutrients, regulated by other components existing in it, until then very unknown. However the concrete definitions about nutrient solutions began appearing in 1860, by means of a contemporary of Liebig and studious of his work, Julius Von Sachs (1832 to 1897). Founder of the Plants Experimental Physiology, Julius Von Sachs was born in Ger-many in 1832, and died in 1897. He was a teacher and researcher in the University of Wurrzburg, where he invented and projected various devices not only for the study of physiology processes of plants, but also for the quantitative analysis of their components. The books he wrote were so well illustrated and with detailed and so precise draw-ings, that immediatelly became standard books for teaching in every Botany schools of the


world. Till today the illustrations of such books are copied to illustrate works and booke of other authors.

67

Fig. 1.37 Julius Von Sachs (1832 to 1897) In 1868 he published “Texts on Botany” (Lehrbuch der Botanik), in 1875 , “History of Botany” (Geschichte der Botanik) and in 1882 “Lectures on Plant Physiology” (Vorlesun-gen Uber Pflanzenphysiologie). Near all the plants he used for laboratorial researches were cultivated in aqueous nutrient solutions, using the techniques discovered and developed by Boussingault and Horsmar. Sachs worked very extensively with W. Knopp (1860), an agricultural chemical, in the improvement of the aqueous nutrient solutions. And finally, in 1860, Julius Von Sachs published the standard composition of a nu-trient solution in which the plants could be cultivated successfully. This marked the end of a long research in the search of the group and proportions of the nutrients vital to plants, and in truth, gave a start parameter not only to the perfec-tioning of the nutrient solutions, but also for the beginning of a new technology. W. Knopp was called the “father of Water Culture” and the discoveries of Julius Von Sachs marked the beginning of “Nutriculture”. Similar techniques are used till today in laboratorial studies on physiology and plant nutrition.


These investigations on plant nutrition, that today we can say that were preliminary, demonstrated that it is possible to reach the normal development of a plant, immersing its roots in an aqueous solution of salts of Nitrogen, of Phosphor, of Sulfur, of Potassium, of Calcium and of Magnesium. These elements began to be called as Macro Elements or Macronutrients, or better, elements needed in relatively great quantities. With posterior refinements in the laboratory techniques, and by the larger and larger development of the knowledge of Chemistry, the scientists discovered seven elements more also needed by plants, in relatively small quantities, that were defined as Microele-ments or Trace Elements. In these we can include the Iron, the Chlorine, the Manganese, the Boron, the Zinc, the Copper and the Molibdenum. After Julius Von Sachs death, the University of Wurrzburg criated the today world famous “Institute Julius Von Sachs of Biological Science”, and restructured his Botany Garden. Aside from the Department of Special Researches, the Institute proporcionates specialization courses on Biophysics, Molecular Physiology, Ecophysiology, Vegetal Ecol-ogy and Biological Pharmacy, among others. Once discovered that water added with the selected chemical elements in the equi-librated quantities support the life of plants, in 1920 were established standards for the laboratorial preparation of water cultures as well as the methods for its use. Many researchers developed several basic formulas for plant nutrition. Among them we can highlight Tollens (1882), Tottingham (1914), Shive (1915), Hoagland (1919), Deutchmann (1932), Trelease (1933), Arnon (1938) and Robbins (1946). Many of their formulas are used till today in laboratory works in researches in plant physiology and nutrition. As mentioned before Shieve yet noted that the nutrient solutions needed to be care-fully monitored for the cultures to reach the desired success. The monitoring was needed not only on their chemical composition, but also on its acid or alkaline reaction. The acid or alkaline reaction of soils has been deeply mentioned by Boussingault, and to make its correction was yet a used practice, to get the best conditions to the devel-opment of plants. From the Discovery of Boyle respect the changing of color of violet flowers extract in the presence of acids or alkalis, other indicators were discovered. However when using them we only could conclude that a determinate solution was more acid or less acid, more alkaline or less alkaline, and sometimes we could verify a neutral reaction. Even by the development of the theories proposed by Svante Arrhenius in 1880, of those from Wilhelm Ostwald in 1894, and those from H. Friedenthal em 1904 who worked

68


since with the application of the Law of Action of Masses to the calculations of ionic dis-sociation constants, the problem persisted.

Fig. 1.38 Soren Peter Lauritz Sorensen (1868 to 1939) There was not a logic scale for the measure, though the cited scientists, without noting it, began to delineate it, especially from the recommendations of Friedenthal for the use the ionic concentration of Hydrogen to characterize the solutions. Once defined a scale, they could proceed to more precise measures of acidity and alkalinity of the solutions. The measuring scale was finally solved in 1909, by the Danish scientist Soren Peter Lauritz Sorensen (1868 to 1939), when he proposed the connotation “pondus Hidrogenii” (Hydrogen potential), that he abbreviated as pH, and defined it as the cologarithm (the real number opposed to the respective logarithm) of the Hydrogen ionic concentration. By its definition, the acidity or the alkalinity of a solution, could be measured in an dimensionless scale that varies from 1 to 14. Then, the colorimetric indicators have gained incorporated to them standard colors based on the concentrations of precision prepared standard solutions. No doubt that the precision in the verification of the pH of a solution was dependent of the skill of the operator, as well as from his visual acuity, a problem that was finally

69


solved by the discoveries of Fritz Haber.

Fig. 1.39 Fritz Haber (1868 to1934) Frits Haber was born in Germany, at Breslau, in December 9, 1868, son of Siegfried Haber and Paula Haber. His father, from an ancient and traditional family was a prosperous merchant of chemicals. His mother died during the confinement, and thus he was the only son during the first years of his life, till the second marriage of his father, from which he got three sisters who devoted him a great affection, though he was ten years older than his older sister. He was a very devoted and lovely stepson, and it was his habit to present the stepmother with white lilies by Christmas time. He attended the public primary school during three years, and afterwords the high school in St. Elizabeth School at Breslau. The curriculum of this school was centralized in Humanities, and for that reason he learned Latin, Greek, Literature and Philosophy. Therefore Fritz developed a great interest for Literature and Philosophy, maintaining this for all his life. The poet of his preference was Goethe and his preferred philosopher was Kant. As it was typical of men from his epoch, he strongly believed in the progress and illumination of mind by the culture. During the high school he conducted yet his experiments on Chemistry.

70


At 18 he entered in the University of Berlin, and this university was the barn of scientists and masters as Helmhots, a great thinker, philosopher and studious of the me-thodology of science, and at the same time he was a physical and a physiologist. From 1886 to 1891, he studied Chemistry in the University of Heidelberg, under the guidance of Bunsen, He also studied in the University of Berlin under the supervision of A. W. Hoffmann, and in the Technique School of Charlottengerg, under the direction of Liiebermann, and at the end of his studies, he worked as a volunteer with his father during some time. After this he began working in the “Technology Institute of Zurich”, with Prof. Georg Lunge, where he decides to follow the scientific career. For that, he worked with Ludwig Knorr in Jena, and published with him a work on the study the diacetosuccinic ester. Still not decided about dedicating himself to Chemistry or to Physics, in 1894 he accepted the post of assistant of Prof. Hans Bunte, full professor of Chemical Technology in the University of Karlsuhe, where he stood till 1911. Hans Bunte was a researcher of Chemistry of Combustion, and his working fellow was Carl Engler introduced Haber in the studies of oil, and this would exert a great influ-ence on his future works. In 1896, Haber was qualified as "Privatdozent" (Free Teacher) as a consequence of his thesis on hydrocarbon combustion, and in 1906 he was named teacher of Physical-Chemical and Electrochemistry, in addition to his naming as the Director of the institute created by Karlsuhe for the study of these themes. In 1911 he was appointed to succeed Engler as the Director of the Institute of Phys-ics and Electrochemistry in Berlin-Dahalen, and stood there till 1933, when the racist laws of Nazism forced the dismissal of all his cooperators, and in support of them, Haber re-signed. He was then invited by Sir William Pope to go to Cambridge, in England, where he remained for short period, as he was cardiac and was afraid of the rigorous winters of that country. In 1898, Haber published his first text book on Electrochemistry, based on his conferences in the University of Karlsuhe, and in this work he expressed his intention to dedicate to chemistry for industrial processes. In the same year he published the results of his work on electrolytic processes of oxy-reduction, and in the following years he worked in the electrolysis of melted salts (1904), in the cathodic equilibrium process of quinone-hydroquinone which opened the way for Billman to discover the electrode to determine the electrometric acidity of liquids. However in cooperation with Cremer, Haber invented the glass electrode for the same finality, which is used till today for the electrometric measurement of pH, within the scale purposed by Soren P. L. Sorensen, with a high degree of precision in a visible scale, by means of the known pH-Meters. This way became solved the problem of measuring pH of nutrient solutions, rapidly, precise and accessible to any laboratory operator.

71


Even so his work was not stopped, though he often regretted the use the “mustard gas” (dichloro-diehtil-sulphide) he discovered during the World War I. But in his maximum, he said: “In war times a scientist belongs to his country and in peace times, he belongs to mankind”. However the great discovering of Haber, which once more puts him in a relationship with Hydroponics and with agriculture as a whole, was the synthesis of ammonium from gaseous Nitrogen and Hydrogen removed from the air. This earned him the Nobel Prize of Chemistry in 1918, which because the World War I, he received only in 1919. When in 1905 he published his work on Thermodynamics of Gas Reactions, he yet mentioned that he was able to get small quantities of ammonium from Nitrogen and Hy-drogen heated at 1,000°C, using Iron as a catalyst. After these experiments, having as his cooperators Bosch and Mittasch, as a func-tion of the experience he already had with gases under high pressures, he began re-searching other catalysts for his reaction, but now, he conducted it under the pressure of 150 to 200 Bar, and at the temperature of 500°C. The process worked perfectly, and from here was Born the "Oppau und Leuna Am-monia Werken", which allowed Germany to extend the World War I, when failed its normal nitrate supplies came from the deposits of guano in Chile, for the production of explosives. With some changes in this process, Haber was able to produce in an industrial scale the Ammonium Sulfate for use as agricultural fertilizer. The same principle used by Haber in these processes, with the development of oth-er catalysts permitted Alwin Mittasch the synthesis of the methyl alcohol. It still permitted the development of the Bergius process for the Hydrogenation of Carbon and the production of Nitric Acid, at an industrial level. And it is a consequence of these works and discoveries of Fritz Haber that today, as a general rule, the hydroponicists and farmers can count on Amonium Sulfate, Calcium Nitrate, Potassium Nitrate, in the quantities they need. Haber lived to science be it by a personal satisfaction, be it by the influence in the molding of the culture and human civilization. Versatile in all his talents, he possessed an amazing knowledge of politics, history, economics and industry, and certainly he would had an equal success on other activity fields, and for that it is not a surprise the awards and laurels he received during all his life, besides the Nobel Prize. Being of Jewish descent, he was expelled from Germany in consequence of the racial purity laws of Nuremberg, as well as Einstein, Freud and others. After the end of the World War I, he was considered a war criminal by the Allied Forces, but was never processed. After a serious illness, he died in January 29, 1934, during a trip from England to Switzerland to where he was going for convalescence. He died nonconformed with the

72


rejection that Germany dedicated to him, a country he served so well. But the interest by nutriculture, in the practical sense of its application, only began in 1925, by means of the greenhouses industries. The soil under greenhouses needs to be periodically changed for one to solve the problems with its structure, pests and fertility. As a consequence of this, researchers began to become aware of the potential of the application of Nutriculture to substitute conventional cultures in soils under greenhouses. Till 1930 the greatest part of the work developed with soilless cultures, was always directed in the sense of the laboratory experiments with plants. Nutriculture, Hydroculture and Chemyculture were other terms used between 1920 and 1930 to describe soilless cultures, and between 1925 and 1935, there was an exten-sive development and great changes in laboratorial techniques seeking its application in large scale productions. It is between the end of 1929 and the beginning of 1930 that Dr. William Frederick Gerike, an agronomist and teacher of plant nutrition in the University of California at Berke-ley in United States of America, extended his laboratorial works on plant nutrition to plant-ings developed on field, looking for commercial applications. We don’t know too much about the life of Gerike, be it at family, and be it at school level. Even at the University of California where he worked, there are very few registers about his life. He was born in a farm at Nebraska, was educated in Ohio State at Johns Hopkins and at California. His experiments on cultures in nutrient solutions, started in 1927, were carried out at the Experimental Station of Berkeley, in the University of California, and his culture tanks at the beginning were at open air. He cultivated hydroponically numerous plant species, especially tomatoes, pota-toes, tobacco, gladioli, begonia and so many others, of which he always expressed his favoritism for tomatoes. One of the plants he was proud of, was a banana tree that grew hydroponically till the roof of one of his greenhouses. In April, 1927, in an interview to the Time Magazine, he discussed his preoccupa-tion with what name he would give to his cultivation technique. Here, we believe that a great role was played by his fellow of the teaching staff at the University, Dr. William Albert Setchell. Setchell was Born at Norwigh in Connecticut – USA in April 15, 1864. He graduated in Botany in the University of Yale, and got his Ph.D. in Botany too in the University of Harward. From 1890 to 1895 he teached Biology and Botany at Yale, and from 1895 to 1934 he was a teacher and director of the Botany Department of the University of California at

73


Berkeley, when he became a colleague and fellow of Gerike.

74

Fig. 1.40 Dr. William Frederick Gericke and his tomato plants


Fig. 1.41 Dr. William Frederick Gericke – Detail of Fig. 1.40 The greatest scientific interest of Setchell was the study of algae, and in this subject he became a great world authority. His researches and investigations extended to Morphology, Systematic, Ecology and Group Biogeography. Among his scientific contributions, one of the most important was the study and elu-cidation of the role of algae in the formation of the coral reefs. In Biogeography he proved to be a follower of the Humboltidian thoughts especially in his examinations of the relation between the temperature gradients and the distribution of matrices not only of algae, but also of vascular terrestrial plants. He participated on several scientific expeditions for data and sample collecting, to Alaska, to Hawaii, to Samoa to Indo-Australia, to Japan and to Africa. He died in Berkeley – California, the April 5, 1943.

75


76

Fig. 1.42 William Albert Setchell (1864 to 1943) The tendency of Gerike was to call his cultivation technique as “Aquaculture”, and he was advised by Setchell to use not that name. Setchell advised him to use the term Hydroponics, from the Greek “hydro” meaning water, plus the term “ponos” meaning work. Gerike liked this name, as he used to say, “It is a strong connotation, economic and useful, and besides that, it remembers the word Geoponics (Geoponya), the term used during the Middle Ages to connote Agriculture”. This generated a myth that remains till today, by which it is credited to Gerike the “invention” of the word Hydroponics. Indeed Hydroponics is a common Word of the Greek idiom, and can be found in any Greek dictionary, be it of the ancient or of the actual Greek. This way, Hydroponics really is the translation to English of the Greek word “HY-DROPONYA”, whose etymology, in Greek, is the association of the word “HYDOR” with the word “PONOS”. It should be noted that in Greek, water is Hydor, and not Hydro. Besides that, in actual Greek, Ponos means “pain”, and in ancient Greek Ponos means “work”, in the sense of “the result of a performed physical work. We must note too that in Greek, Hydor is a word of the female gender. On the other hand, Ponos presents three genres, namely, masculine, feminine and neutral, and respectively, Ponos, Ponya and Ponion.


In Greek, to join two words and make a composed third one, both need to be in the same genre, ad so we have HYDOR+PONYA. Still considering the Greek etymology, when we join these two words, the final “OR” from HYDOR is inverted to “RO” and thus we will finally have the word HYDROPONYA. When translating to English the “Y”s nemain, and PONYA is translated to “ponics”, from where we have the term HYDROPONICS used in the British language. In the Latin languages, the “Y”s are substituted by “I”s, and we finally have HIDRO-PONIA. It is good to remember here that in not too old times, both in Portugal and Brazil the “Y” was known as “Greek I”, and in Greek there are five “I”s. According to the “I” used, one only word in Greek can have five different meanings. So we see that it was Dr. William Albert Setchell, and not o Dr. William Frederick Gericke who denominated the new agricultural technology as Hydroponics. It was our intention here to simply clear the reader, and who knows, to break that myth, though we believe that it will remain for a long time. The success of the work of Gericke, was tremendously great, and in that epoch var-ious farmers embraced the new technology, apart from that various research centers on Hydroponics were developed in other universities Our scientist even had a “fan club” where he normally received up to 500 letters a week. It is also known that he attempted to patent his technology but he didn’t succeed, as hydroponics is an agricultural technique, and therefore is of public domain. He only got a patent for a tank to dissolve the mineral salts used in the preparation of nutrient solutions. When inquired about if he desired to make a fortune with his invention, he only smiled showing his golden teeth. He never charged consulting fees from anyone, and always said: “Everything I want is that you succeed and earn money for you to help me to continue with my experiments”. But not all was as white clouds in his work. Immediatelly after the use of his technique by several farmers, some companies began selling nutrient salts and salt mixes for hobby producers, and even to some profes-sionals. Within them were the Chemi-Grow, the Chemi-Crop Co., and the Shur-Gro Fertilizer Corp., besides others. Though they were legally in their rights, as hydroponics was a technique and could not be patented, Gerike did not agree with them and nor even tried to charge some of them, although they used his name. He always declared and publicly accused them of victimizing innocent people offering them miraculous solutions, as each plant required its own nutrient solution, and such solutions could not be generalized. It was necessary to consider climates, ambient conditions and the managing of

77


those solutions respect pH, Electrical Conductivity, as well as, many times, to heat the nu-trient solution, something that was normally used by Gerike. In 1934 he contracted a photographer, Arthur G. Pillsbury, who after photographing all his gardens and hydroponic plants, went to Evanston – Illinois, where he raised several interested companies, including a banker and a lawyer, to enter in the “hydroponic busi-ness”. Back to Berkeley, Pillsbury requested technical information to Gericke, who declined to provide them. Then Pillsbury went to the Dean of the College of Agriculture at the University, who gave him some pamphlets about the work of Gerike, which were available for free to whoever wanted them, that papers containing nutrient solution compositions, working temperatures, aeration, etc.. With this in hands, and saying that he got confidential informations from Gerike, he was able to incorporate himself to the Chemical Garden Co., that began producing and selling mixes of salts for nutrient solutions. At the same time they hired a trained plant physiologist, and installed hydroponic tanks for research. When Gerike knew this, he simply laughed. The relationship of Gerike with his working fellows and superiors at the Agriculture College also became very tense after the development of the technology. Gerike was frequently criticized, and his work in the University has never been ap-preciated, and frequently he was treated with sarcasm. They said with contempt that by one side Gerike kept too many secrets on his re-searches and technical developments, and in the other hand that he was more preoccu-pied with publicity and marketing. They categorically stated that the scientific use of hydroponics should be for the learning of plant Physiology, and that the possibilities for its commercial use could not be proved, besides that the productivities were smaller than those obtained in soil. Everything contrasted with the evidence Gerike presented, as much greater produc-tivities than those obtained in soil, besides his free consulting to everyone who looked for it. May be due to these difficulties of relationship, very few of his works were published by the University, and one of the rare ones was denominated “Some Effects of Salts on the Absortion of Water by Seeds”. By means of an editor not tied to the University, in 1940 he published the book “The Complete Guide to Soilless Gardening”, where he describes his work of years in hydro-ponic cultivations, a work till today necessary in the library of any researcher on Hydropon-ics.

However, among all these disappointments, many ones deeply appreciated the work of our scientist.

During the Summer of 1937, the “National Resources Committee” included Hydro-ponics along with the conditioned air techniques, synthetic rubber, television and cotton

78


harvesting machines, as some of the things that should be observed in the future devel-opment of American national economy. And for the first time, in May, 1938, hydroponics goes out of the continental borders of USA. Even considering the skepticism o some against the commercial value of hydroponics, and others, considering the recommendations of the National Resources Committee, the Pan American Airways, intelligently decides for the installation of hydroponic gardens at open air in Wake Island. Their purpose? To supply their fixed staff and their aircrafts, with fruit and fresh vegetables, and everything under the free guidance of Dr. William Frederick Gericke. The work of Gerike is considered as the basis of all forms of hydroponic cultures, though it was primarily limited to the culture of plants without the use of any rooting me-thod. We tried here to show some facets we were able to find about the life of this emi-nent scientist, to whom the world owes so much, and as it always happens, misunderstood and unappreciated even in the research centers where he worked. The term Hydroponics, today covers a more ample concept, being used to describe the various methods by which we can cultivate plants without soil. We consider here as soil, the substrate where plants anchor their roots, and from where they absorb water and the nutrients needed for their development. These methods many times also known as soilless gardening, include the cultiva-tion of plants in pots with water and any inert substrate. This water will always be, in truth, a nutrient solution. The substrate can be gravel, sand, vermiculite, besides others more exotic as crushed stones, volcanic lava and even expanded polystyrenes, or PVC shavings (Poly-vinyl Chloride). Many Hydroponic methods use substrates constituted of organic matter that can decompose, as peat or wood sawdust, and in this case can only be called “Soilless Cul-tures”. True Hydroponics is the method by which plants are cultivated using exclusively an aqueous nutrient solution. There are several reasons to substitute soil by a sterile medium. Pests originated from soil are eliminated, as well as are the weeds. This way the labour to eliminate such weeds as well as the one expended in the surveillance of the plants is strongly reduced if not eliminated. One of the most important factors of Hydroponics is that by practicing it we can raise the density of plants, in other words, we can cultivate more plants by unit area of cul-ture in levels much larger than those permitted in soil, a reason by which this technology provides a larger productivity. By Hydroponics, grains and fruits ripen more rapid and present a better income.

79


Water consumption is much lower, and the fertilizers dissolved in it remain there, and can be reused. This process permits us to exert a better control over the plants, and with this we can assure more uniform results as we can keep a perfect relationship between them and their development ambient. Plants don’t need soil but need the water and nutrients reservation it contains, and these last, must necessarily dissolved and ionized, for the plants to be able to absorb them. When we plant in an inert growing media without a self nutrient reserve, we can be sure that plants will look for their food in the nutrient solution with which we will moisten said media. The tendency of conventional soil is to permit water and nutrient leaching away from plants which makes fertilizer application a difficult task. In Hydroponics the needed nutrients are dissolved in water, and the resulting solu-tion is applied to the plants in the exact dose, in exact periods of time, and normally in the ideal temperature for the roots. Dr. Gerike cultivated various vegetables in water, including those utilized by the roots as beets, radishes and carrots and those utilized by the tubers as potatoes. In addition to these he planted vegetables utilized by the fruits as tomatoes and those utilized by the seeds as maize and other cereals, as well as several floral species. Using water culture in great tanks in his laboratory at the University of California he had a great success in the production of tomatoes, which plants reached eight meter high. At that time the American newspapers published photos showing Dr. Gerike on the top of a ladder to reach the top of his tomato plants. Though it was very spectacular, his system was premature for commercial applica-tions, as it was very sensible, and required a constant technical monitoring. Many people who decided to be future hydroponicists had many problems with the Gerike System, as this required large technical knowledge. Besides that the needed knowledge was not accessible to anyone, the system also required a lot of ingeniousness to be built. Even so the American Press made its usual fuss saying that the discovery of the century was made, though here there was a small parcel of reason. Partly due to this inconsequent promotion many unscrupulous took the opportunity to earn easy money using the Gerike process selling misleading products and equipment, that during many years provoked a discredit on Hydroponics. Even so the researches continued and soon Hydroponics began having very solid scentific bases, demonstrating that it was a tool of future, especially for horticulture. The new technique presented two great advantages: great productions in small areas, and the principal, it allowed the production in arid areas, not arable, existing in se-

80


veral parts of the world. In 1936, W. F. Gerike and J. A. Travernetti, both from the University of California, published a final report on tomato plants in aqueous nutrient solutions, which was a great success. From this report on, many farmers now bearing better technical bases began expe-rimenting with the system. At the same time, various researchers and agronomists of var-ious schools began working with the scope of simplifying it. A great number of Hydroponic complexes were built in Mexico, Puerto Rico, Hawaii, Israel and in India. In United States, now without great public information by the press, Hydroponics became a big business, and more than five hundred greenhouses were built for hydroponic production. The technique of Dr. Gerike proved by itself to be able to produce food for the American Army Troops camped on the desert islands of the Pacific. The first great victory of Hydroponics came when the aviation company Pan Ameri-can Airways, as we told before, decided to build a hydroponic complex in the desertic Wake Island, at the middle of Pacific Ocean, to provide a regular supply of fresh vegeta-bles for its staff and passengers. It is at this time that the English Ministry of Agriculture, began having interest in the new agriculture technique, especially by its potential in the campaign "Grow More Food" that happened during the World War II, from 1939 to 1945. During the year 1940, Robert B. and Alice P. Withrow in their works at the Purdue University in United States, developed a series of improvements in gravel culture system with intermittent irrigation, which made Gerike’s system much more practical. This system began being called Gravel Culture. During the World War II, sending fresh vegetables to overseas posts in the Pacific Islands, was extremely expensive and not practical, and on the islands those posts were located were desertic and inadequate to agriculture. So is that the United States Armed Forces, made Hydroponics pass by its greatest viability test, when they built on those islands various installations with hydroponic tanks with gravel for the production of greens. The installations were perfectly approved, and in 1945, they solved the problem of supplying fresh greens for the occupation troops, and troops in transit. One of the various hydroponics installations built by the American Army was at the Ascencion Island in South Atlantic, a region totally arid, used for the rest and replenish-ment of the troops. The permanent staff in the island was very numerous as in the same it was also made the service of aircraft maintenance. Food supply to this place was made by sea and by air and the lack of fresh vegetables was a constant problem. The refinement of the Hydroponic technique carried at Ascencion, served as the basis for many other installations in the Pacific Islands, as Iwo-Jima and Okinawa.

81


In Wake Island, an atoll of the Pacific Ocean at West of Hawaii, where yet existed a hydroponic installation of Pan American Airways, the U.S Air Force built a small hydropon-ic installation in volcanic rock gravel with an area of twelve square meters. In this small installation was weekly produced 15 Kg of tomatoes, 10 Kg of green beans, 20 Kg of ears of corn and 20 lettuce heads. At this same time, the English Ministry of Aeronautics began hydroponic cultures in its air bases in Habbaniya desert in Iraq, and on the desertic Baherein Island in the Persic Gulf where there were important oil fields. In Habbaniya, for instance the greens had to be brought from Palestin at extraordinary costs. Not only the American Army as well as the English Royal Air Force built their hydro-ponic installations that produced thousands of tons of vegetables which fed thousands of military. After World War II the American military command continues to use hydroponics, and created an internal specialized department that provided the production of 4,000,000 Kg of greens and other vegetal products during 1952 an year of peak in the military demand. It established too the greatest hydroponic installation of the world (by that time) in a project of 22 Ha in the island of Chofu in Japan. It is curious one of the reasons for this installation. It was a common use in Japan to fertilize soils with composted human dejects, and thus their soil was infested with amoebae and various other viruses. Curiously the local people was immune to these infestations, may be because their organisms adapted through the centuries, to the contact and ingestion of the causative of gastrointestinal diseases, which did not happen with the western people. This way they avoided to eat “in natura” vegetables to avoid such diseases. As a consequence, they suffered with avitaminosis, and they had to ingest massive doses of industrially prepared vitamins. It is known that only about thirty per cent of vitamins industrially prepared are assi-milated by human organism, and this treatment generated exorbitant costs which were larger when veggies “in natura” were brought from distant sources in an attempt to solve this situation. Hydroponic gardens were the economical solution. It is interesting and important to know that the Japanese knew Hydroponics by this time. Hydroponics is not a Japanese invention or discovery as many people say. No doubt that today we have immense installations in Japan, but some time ago, in this country they did not use very actual agricultural techniques. Those facilities then built in Japan, besides producing vegetable seedlings for other complexes, produced normally adult veggies for consumption. They stood in continuous

82


operation during fifteen years. This way, forced by the war, the greatest hydroponic installations were spread by the world, all them in gravel, and those that had a better success were always the ones of isolated military bases, remarkably in the Guyana, Iwo Jima and at the Ascencion Island. After the war various commercial installations have spread by the world including United States, especially in Florida, great part of them at open sky, subjected to the rigors of weather. The deficient construction and the lack of technical knowledge leaded many of them to failure and to low production. But even so, by the time of 1959, the commercial use of hydroponics has spread over the world in countries like Italy, Spain, France, Sweden, Russia and Israel. One of the greatest problems of the first hydroponic installations came from the concrete used the construction of the tanks. The limestone resulting from the lime and from the cement used, dissolved in the nutrient solution, unbalanced its composition and even destroyed it. Besides that, the metals used in piping and valves also affected the nutrient solu-tions, especially the Zinc and the Iron used in galvanized iron pipes that corrode easily, and their components enter the solution in such high contents that become toxic to plants. Even so the interest in Hydroponic cultures continued, by several reasons. Firstly because there was no need of soil, and the population of plants was much more concentrated, permitting great productions in very small areas. Second, because when correctly operated, with the majority of vegetables, one can speed up their development, and these present a high degree of quality, especially after harvesting, as they remain fresh during much more time, preserving their feeding qualities. Many petroleum mining companies built large gardens in their complexes, especial-ly in desert areas where there is no water in the sub-soil, or very rare if not existing rain falls, and so with no conditions for conventional soil culture. Other gardens were built too in desert islands as in Caribe. The commercial installations in the Eastern U.S., by that time, reached more than 40 Ha directed to the cultivation of greens to supply various cities, whyle several oil companies in Western India, in the American Midwest, in Desert areas of the Arabian Peninsula and in the Sahara Desert, found in Hydroponics the only way to proportionate a healthy diet and rich in greens for its workers. The same happened with several oil companies operating in Venezuela, Aruba, Cu-rasao and in Kwait. Still in United States, great installations were set in Illinois, Ohio, Arizona, Indiana, Missouri and in Florida. Other installations were also built in Mexico and Central America. Besides the great commercial installations built between 1945 and 1960, many things were made in small installations in apartments, houses, backyards, to plant flowers and greens.

83


Many of these were unsuccessful because several factors as inconvenient substrates use of inadequate construction material, especially in the tanks, and bad control of the operation conditions. However even with the failure in many installations, growers in all world were con-vinced that their problems, sooner or later, would be solved. In the great majority the conviction that the improvements in that technique were coming every moment, and to produce food was absolutely essential in sight of the declin-ing of the world production and of the demographic explosion. Recent surveys show that only in United States, there are more than 1,000,000 working home installations producing greens. Russia, France, Canada, South Africa, Hol-land, Japan, Australia and Germany are among the various countries that have given to Hydroponics the place it deserves. But this is not all. Between 1930 and 1960, a similar work to that developed in the production of food for humans was made to produce food for domestic animals. Researchers verified that it was possible to produce animal green fodder from ger-minated seeds. By using grains as barley, oat, wheat and corn, they verified that on average, 2.5 Kg of them can be converted in 18 Kg of fresh fodder in only seven days. This one used as a supplementation of conventional feed became highly benefic to mammal animals and birds. Used for lactating animals, milk production raises around thirty per cent, and the conversion relation raised a minimum of twenty per cent, at a lower cost per Kg of grains. In terms of reproduction the potency of males and the conception of females in-crease frighteningly. In the farms, egg production increased nearly 40 percent, while simultaneously disappears cannibalism, a constant problem in these creations. Here, once more there was the need to develop a system that could offer a constant production, and new problems appeared. The first systems had no control over ambient temperature and humidity. The funguses were a constant problem in produced fodder. So it was verified the need of clean grains with a high degree of germination for one to get a good growing rela-tion. Even so, face these and other obstacles, and thanks to the continuous work of ded-icated researchers, a system continued to be improved for the production of this high quality and precious food in a continuous way. Thus, with actual technologies, good equipment and good materials, we have today commercial units that work without problems. Many of these are working in small and large farms and in zoos throughout the world. Hydroponics arrived India by 1946. The first research unity was built in the Expe-rimental Farm of Bengal Government, at Kalimpong, in the district of Darjeeling. Many problems had to be faced, being them peculiar to this sub-continent. Known and yet studied problems yet in use in America and England showed to be inadequate for

84


general use in the care of Indian population full of peculiarities. The known and needed equipments were very expensive, and so, prohibitive, not forgetting the existence of physiologic local problems. A new system in which the practicability and simplicity would be primordial points would have to be developed, for Hydroponics to succeed at Bengal. Today with that simple and inexpensive system, thousands of farmers produce es-sential vegetables in the roofs ant backyards of the houses, proving that the system is use-ful even under adverse conditions. Countries of all the world congratuleted the Indians for their assiduity in research and by the results gotten. However, a question always arises: Why use Hydroponics if we have arable lands? Isn’t it better to improve the managing processes, the kinds of fertilizers and the more diffused usage of organic composting? And the great conclusion: At the end, hydroponic products have no difference from those conventionally produced in soil under ideal conditions!!! These statements bring to our memory the statement attributed to Charles II, (Brit-ish Monarch from 1660 to 1685). Emphasizing the difference between him and his brother, the Duke of York (after, James II), it is told that Charles said: “Jamie would do it if he could, but I can and I do it”. Almost all the criticisms to soilless cultures fall into the category of this sentence. And in truth, where can we find such ideal soil conditions? To grow in greenhouses using soil, requires a lot of caution and expensive labor, as a periodic disinfection of the same and of the greenhouse structure. Besides that, to get relatively good lighting conditions, the greenhouse should be lined with glass, thermoplastics or thermosetting plastics, and the two last ones with the best possible transparency degree. Even so, the inside soil must be periodically substituted even when one uses cul-tures rotation. Only this way, in greenhouses, one can have, for short periods, soils that can be near the ideal conditions. Some years ago the Forbes Magazine published na article entitled “Food Supply – The Help of Science Will Arrive in Time?” In this article Hydroponics is considered as the greatest happening of the century, and able to rapidly solve the problems of food in the world. By the same time, the New York Times newspaper published an article entitled “Hydroponics: A new chapter in Food Technology” that said: “…in the last years Hydro-ponics was refined to such a point, that today it is a commercially viable system to produce food.” By reading articles on newspapers and magazines, anyone may be carried to be-lieve that Hydroponics is a recent discovery of scientific technology, predestined to save

85


the world from starving. No doubt that Hydroponics can cooperate, and very much, in the missing of food, but in no way it is a new scientific development. In fact the first plants developed on our planet were hydroponic. Today more than a half of plants for use “in natura” are hydroponically produced. And more, the most healthy and nutritious plants existing today are hydroponic. We are speaking of the plants that develop within the water that covers more than 70 per cent of the surface of the Earth, in the form of lakes, rivers and oceans. There is no arable soil in the oceans. Aquatic marine plants retire all the nutrients they need, from the most complete known nutrient solution that is sea water. From the known institutions that gave the largest contributions for the development of the soilless cultures, no doubt, they were the Universities of Illinois, Ohio, Purdue and California, in United States, and the University of Reading, in Great Britain. In Canada, it was the Central Experimental Farm, at Otawa. Great multinational companies also had their participation, as the Imperial Chemical Industries Ltd. (ICI), that made the adaptation of Hydroponics for the British conditions. Other pioneers of Hydroponics were the Boyce Thompson Institute for Plant Re-search, in New York, the New Jersey Agriculture Experimental Station, the Alabama Poly-technic Institute and the Horticultural Experimental Station, at Naaldwijk in Holland. Today Hydroponics is a well defined agricultural technology, but the researches and studies do not stop. Variants of the process continue being tested and improved. But there is no slack given to researchers and scientists. For instance, the greenhouse industries in England, face the high costs of the instal-lations, beyond the technical knowledge needed to make them work satisfactorily, claimed for an easier operational system, ad at an initial construction lower cost. That is why at the Glasshouse Crops Research Institute in Little Hampton at the South of England, it was gathered a staff of researchers under the command of Dr. Allen Cooper. This group of scientists was fully convinced that Hydroponics was something commercial viable, and from it, by the middle of 1975, emerged a system that has revolutionized Hydroponics: the NFT – Nutrient Film Technique or Nutrient Flow Technique. Dr. Cooper describes minutely all the details of the system in his book “The ABC of NFT” edited in various countries of the world. This system was not the result of an experiment that worked. It is based in very deep concepts of plant nutrition and physiology. Besides this, in it Dr. Cooper put in practice a series of personal concepts that bro-ken a series of myths created around the plants, as for instance, the one that “plants are perfect living beings, as they feed on what is strictly need for them, and they don’t need to deject. That is why they have no excretory system”. Dr. Cooper has proved that this is a myth.

86


Fig. 1.43 Dr. Allen Coopper (at 83 years old) The principal characteristic of the NFT Hydroponic System is its low initial cost, al-lied to an extremely simple managing of a low cost too. From England, where it spread rapidly and frighteningly, it expanded to the world, being New Zealand and Australia the countries that were the flag of its adoption and subsequent adaptation to the majority of plants. The system has its limitations and dependencies, but these are being rapidly over-come, and as a consequence it has given margin to many variations that sometimes misrepresent its basic working principle.

87


The greatest limitation of this system is its complete dependence of electrical ener-gy. Today, around eighty per cent or more of the greens produced by Hydroponics are offered by the NFT System. As the name of the system suggests, its working principle is based on the feeding of the plants by means of a thin film of nutrient solution that runs as a continuous flow or in determinate periods, bathing the tips of the plant’s roots. At the writing of these lines, Dr. Cooper is still alive, 83 years old and still continues researching and developing a new NFT System that does not use electrical energy. Here we could not avoid citing the work done by Dr. Franco Massantini of the Uni-versity of Pisa, in Italy, who is the father of a system today called Aeroponics. Massantini idealized a system by which the plants stay with the roots suspended in air, and are fed with a nutrient solution that is periodically misted over them by means of micro sprayers or nebulizers. The Massantini system, in truth, constitutes a real mark in cost reduction of energy and installations. The installations to carry the system are very cheap, and an important thing is that they are not rigidly tied to the greenhouses, are very mobile and adaptable to various kinds of crops. We can say that Aeroponics as the Massantini system is known today is still crawl-ing, and much remains to be researched and adapted to process. With the Aeroponic system today can be commercially cultivated since greens for salads and spices, to fruits like tomatoes and cucumbers and tubers such as potatoes. We take the liberty to discern that the Aeroponics in a short time, will probably replace almost half or more of the NFT system. 1.2 – THE PRESENT With the development of plastics, Hydroponics had one of its greatest growing. In truth if there is a factor to which, by itself, we must credit the great success of hydroponics industry of today, it is the development of plastics. As mentioned before, one of the greatest problems found in all hydroponic installa-tions, was the constant dissolution in the nutrient solution of the materials used in their construction, as concrete, galvanized iron pipes and the materials used to support the roots in the nutrient solution. With the advent of fiberglass (glass fibers reinforced with polymeric resins), as well as different kinds of vinil plastics, polyethylene films and the various kinds of plastic pipes, these problems were virtually eliminated.

88


In the best production systems built today around the world, plastics are used in all their extension and we can say that in them there are no metals.

Fig. 1.44 Dr. Franco Massantini Even the water pumps used in the systems are coated with epoxy resins, be it en-tirely or even manufactured with them. Using such materials and inert materials for plant rooting media, the hidroponicist is in the right way to the success. Plastics liberated the producers from costly constructions of the tanks previously used. One just digs the existing soil, lines the hole with a vinil film, and fill it with the root-ing system. By the development of adequate pumps, time controllers, plastic pipes, solenoid valves and other equipments, all the hydroponic system can today be automated, and even computerized, reducing not only the invested capital but also the operational costs. A basic premise that one should keep in mind about hydroponics is its simplicity. After the invention of the wheel, many ones became confused, and thought it was something very complicated. It was because they could not immediately imagine how much work it would save to

89


them. By conquering the idea, we can verify that it is something.......SIMPLE. Another mark conquered in Hydroponics was the development of nutrient formulas completely equilibrated. In this area the work continues, however we can find in the mar-ket many ready formulas. Greatest part of them is quite good, but only some, if there is one, will work correctly without the use of additions during the various stages of development of the plants, though for the majority of the producers it is better to begin with one of them. Additionally to the speed of the progress as a function of the use of plastics and to the slow growing due to mixes of nutrients, another factor of great importance for the fu-ture of the hydroponics industry was the development of the greenhouses internal ambient control equipments. In the beginning, near all greenhouses, when necessary, were heated with steam equipments, and the cost of such equipments was a great barrier to small producers to start in Hydroponics. With the advent of high speed heaters using gas or light oils, it was possible to build smaller and high efficiency and cheap heating units. Besides that, the use of LPG (liquid petroleum gas), made these units easily mobile, permitting the installation of a greenhouse anywhere. Even so, in great installations, the use of boilers is the most economic option. In the same way as with heating equipments, there was else a great development in cooling units. Even when it comes to greenhouses, the use of materials as polyethylene and vinil films, as well as fiberglass plates, allowed completely new techniques in the construction of the same, drastically reducing their manufacturing costs. Today it is possible to construct greenhouses with any size or shape, at affordable costs. Some of these materials only have the durability of just one crop. Others are granted up to 20 years against darkening that causes light losses and against cracks caused by hail. With the new materials, despite the damage to the coverage, practically there are no damages to the cultures. But by the use of extremely thin films or even glass, when there are damages to the coverage, inevitably we will have losses of cultures, sometimes total losses. The films are good for temporary or semi-temporary coverage. Some coverage materials, today, proportionate light diffusion, which is very impor-tant e beneficial to the cultures. The combination of ambient controls as well as the development of the hydroponic systems, during these last 20 years, has been a reason for the great growth of parallel in-dustries tied to them, and with that, we can be sure that in the future Hydroponics will represent a great role in the feeding of the world.

90


Hydroponics became a reality for growers in greenhouses, in regions with any cli-mate. Today we have hydroponic installations spread over the four corners of the world, and many of them in regions where no one could imagine that a plant could born, grow and flourish. The inordinate growth of the great urban centers has gradually reduced the fertile lands around them, pushing their sources of food supply for increasing distances. This makes these foods become more and more expensive due not only to the great distances they have to travel but also to the elevated costs of their preservation. In face of the characteristic of Hydroponics of giving high production levels in small areas without the need of soil, even on the roofs of the buildings of the great cities, can be produced a notable quantity of food. And this is yet a reality. We only need electrical energy, sometimes a combustible and small quantities of water (1/25 of the water normally needed for the culture on soil). And we will have food exactly inside the consuming centers. Today we have hydroponic gardens installed in nuclear submarines, in space sta-tions and at the marine stations in the offshore oil drilling not speaking here about the great zoos that keep great part of their animals healthy, thanks to the hydroponic fodder produced in their own installations. In our days we have too large and small installations used by companies and people at their homes. Even at the Baffin Island and at Eskimo Point in the Canadian Arc-tic. Commercial producers use this marvelous technique to produce food in a large scale, since Israel to Armenia and to the Sahara. There are installations near the sea, using desalinated sea water, and even in desert Areas, using treated brackish water. If in the whole world there is an industry whose success hour is arrived, it is HYDROPONICS. Why produce food? There are many and good reasons. In our great consuming centers, food is something considered as granted, though some of its items, some years ago, be it by necessity, be it as a hobby, many people produced it the homey way. However, since long time it became easy to go the supermarket and to by what one needs, most of the time no matter the price, and for the majority of people, giving no great importance to a better or worse taste, or even to the greater or lesser nutritional index value. When one spoke on fresh veggies, if they were large and beautiful, if they could be bought at a reasonable price, nothing else mattered. But during the last years things are changing. The consumer is more interested in costs and much more preoccupied with taste and the nutritional value of the food he gives to his family. Countries like the Canary Islands equilibrate their annual economy exporting great quantities of tomatoes, cucumbers and hydroponic veggies to industrialized countries like England. The Caribbean, Puerto Rico and Mexico send great quantities of fruits and hy-droponic veggies to markets of United States and Canada.

91


In England, Germany, France, Holland and Switzerland, companies producers of flowers prefer to use Hydroponics for commercial purposes, specially for the production of carnations and other floral species. On the Colorado – USA and neighbor states, roses are extensively produced for exports. In the United States, only on the flower production field, in 1971, 21 million dol-lars were exported. In Russia, soilless culture in being considered as a bio-industry, positioned between agriculture and the industrial system. Other countries, some of them we did not mention here until now and where Hydro-ponics is extensively used, include Spain, South Africa, Israel, in particular the Negev desert and at the long of the Dead Sea, Italy Scandinavia, Bahamas, Central Africa, West-ern Africa, Kwait, Brazil, Poland, Seychelles, Singapore, Malaysia and Iran. This list is incomplete and is not so extensive, but it can give a real idea of how much Hydroponics is today spread by the world. As time goes by, more and more people have to be fed, and it is incredible that ara-ble areas in one way or another become more and more scarce, as well as the farmers, be it for the bad financial return from his work, be it by the fascination the great urban centers exerts over the more humble among them. If we continue like this, we believe that the demand for food, some day, will overlap our capacity to produce them, as it happened in the past. Who knows if we will not have to resort to diet regimens, or at least to programs to reduce or to eliminate our food waste, as we had to do for energy economy since the petroleum crisis? We don’t want here to frighten anybody, or to presage a catastrophe. We believe that no one will starve, but we must review our position about the nutrition power of our food, for us to feed a larger quantity of human beings with less volumes of it. And how much will cost those foods, when compared to our monthly income? A few years ago in São Paulo city – Brazil, for instance, our “green belt” was no more that 25 or 30 Km distant from the city geographic center, what means that it was sur-rounded with horticulturists. We had local producers with abundance of veggies, milk, chicken and eggs that were offered at the door of our houses. By that time, a “fresh” food was really fresh, and the local producers didn’t know the technologies as they are today. Fresh products, as told before, were offered at the doors of our houses, and we would never think in buying them frozen or canned, a thing that would never pass by our thoughts. Today, the things are presented to us in a different way. Local producers disap-peared. We have today great producers centralized in large agricultural properties, and large food processing companies using lots of…… chemical preservatives. It is not the produced food that carries the chemical products. It is the chemical

92


preservatives that are constituted by chemical products that, as granted by the sanitary authorities are innocuous to our health. Are them really innocuous? We can no more ignore the scarcity of food in the world. We need to produce food in larger and larger quantities, in smaller and smaller areas, and for that, we have to offer ourselves to some sacrifices. We will have to sacrifice “fresh” food, and to stop the use or stop the offer of those “really fresh”. Let us consider the losses of food produced today. About 20 or 30 per cent of them are lost in the producing areas. Now let us add to this the costs more and more high, related to packing, storing, preservation and transport, and the results are quite clear. We need to produce much more, to conserve even more. Hydroponics is not “THE SOLUTION” but it is “A SOLUTION” among many ones. Till now we spoke of vegetable products for human use. Let us now speak once more of animal production. The Hydroponic system known as Herbagère, invented by the Belgian botanist Gas-ton Perin, today is more and more spread by the whole world. This technique is based on grain germination in trays, kept in climate chambers. With it we can produce various kinds of fodder to feed cattle and poultry and is even being used in great extension to feed herbivorous animals in zoos. The production cycle of fodder of barley grains is around seven days, and the con-version rate reaches 1:10. That is to say that 1 Kg of grains gives us 10 Kg of fodder. In an area with 25 square meters we can produce 450 Kg of fodder per day. Even perennial plants can be hydroponically produced, as alfalfa and others. To produce high quality alfalfa in soil is a herculean task. But hydroponically firstly consider-ing the peculiarities of the technique, is something extremely simple. And that plant called Confrey? In soil it is a plague that can infest it as a weed, but the birds, especially chicken and hens, like them in such a way, that they become despe-rate when they feel its odor at a distance of 20 or 30 meters. By producing it hydroponically, it will never be a weed, and it is so simple as to pro-duce a lettuce head. About its sustaining power, without considering its medicinal proper-ties, well, let us ask the Russians that feed their squads almost exclusively with it. Now we ask again, “Why produce food”? We believe our reader found the answer in these lines. 1.3 – THE FUTURE Hydroponics is a young technique. Many authors and researchers consider it as a Science. It is being commercially used only a little over 70 years. However in this short period of time it was adapted to the most diverse situations,

93


from culture at the open air, in greenhouses and specialized cultures in nuclear submarines to get fresh veggies for crew members. It is a science of the space era, and however it can be used in underdeveloped countries of the third world, to produce large quantities of food in short areas. Its only restrictions are fresh water, nutrients and sometimes electric energy. Where there is no fresh water, Hydroponics can use brackish water or desalinated sea water. Where there are no industrialized nutrients, it can use those extracted from animal manure treated in biodigesters. This way it has an enormous potential for application in providing food in non arable lands, as are the deserts. The hydroponic complexes can be located along sea coasts combined with desali-nizing units fed by various combustibles or by atomic energy, and even using the sand of the beaches as a substrate. Another field where Hydroponics promises to play a great role is in the production of tree seedlings for reforestation, for orchards and for ornamental shrubs. In reports published in 1966, researchers of the University of Wisconsin declared they were germinating seeds of white cedar, spruce, red pine and others by the hydroponic system. The result of this experiment showed that in one year the seedlings developed three to four times more than those in conventional systems in soil. They related too that in one only station in this region, as a consequence of the high concentration of plants per area unit, they produced ten times more seedlings than by the conventional processes. Hydroponics not only allows the production of food with a high population density of plants, but also does it in regions of small area with a high human population density. A typical place where this happens is Hawaii, where the tourist stations reduced drastically the yet small arable areas. Besides this, in function of the violent raising on the population of tourists we have an enormous population density. But some problems exist that continue breaking the development of Hydroponics as a whole. One of them is the negative attitude of directors, masters and people of high position in our agricultural schools and universities as well as in some government de-partments. Those attitudes go since the total disinterest, reaching a declared hostility. And in its majority they are the result of their reluctance in accepting or even to study systems that can conflict with their traditions. Finally one seeks to destroy what is not known. But fortunately, around this world there are people that not only have open minds, but also are sufficiently generous to help producers to build their hydroponic complexes. Another problem that developed in these last years, especially in cold climate areas,

94


or in areas with rigorous Winters is the consecutive rise of energy costs. But for these cases a light is emerging at the end of the tunnel with solar heating equipments. There is still much to be done and researched in this field, but there are already units for this purpose on the market. Also there have been publications with project and construction details for those units that make possible for the users to construct their own equipment. There are plans for the use of Hydroponics during space flights, and even for the installation of units in the Moon or beyond. To Hydroponics, the future looks bright. The greatest danger on the growing and development of Hydroponics has been the momentary opportunists that appeared during these last years. The success of many producers with correctly installations and equipments correct-ly designed and selected, attract those “self entitled specialists and authorities” that each time appear in a great number, even in Universities. Making claims of credits in their favor, they have sold ancillary and outdated facilities, besides poorly made copies of units that have worked there as it is known, ensuring that this is the easy way to make money. These promotions and advertisements have been short-lived, but unhappy and maliciously, others remain to appear. For the future producer, the cost of an installation correctly designed based in a good ambient control in the greenhouses, can reach some thousands of dollars. That is why to the future hidroponicist it is recommendable a careful verification of the advertisements that appear, requiring proofs to the sellers, included here their profes-sional capacity, the exhibition of already producing installations they built, research train-ing, and informations about the past of the supplier. For those who pretend to build his own installation, developing his own project, what sometimes is advisable, and why not necessary, remember that a beginner with no experience with agriculture, by means of Hydroponics, can produce with a great success. He will have some difficulties? Yes, but where difficulties don’t exist? Believe that who has a small greenhouse with 12 square meters, with Hydroponics he will produce the fresh veggies for a four or five people family, once he keeps his production during all the days of the year. And that is easy. Hydroponics is highly commercially profitable if the producer devotes to it the time and attention that any business requires. You want to produce tomatoes? The production of these fruits using Hydroponics is 18 times larger than by the conventional processes in soil. And rarely will be necessary to use pesticides on your crops. Hydroponics is something fascinating. Try it and you will see how rewarding is to see your plants born, grow and fructify, and after, garnish your table, and finally delight

95


96

your taste and appetite. And what is even more important, to say, "I planted, and I picked." Our reader can then confirm what said in his reports to the King, the priest that arrived in Brazil with the discoverers, - “Majesty, in this land, planting it, everything goes”. All we need is to plant. So, let us plant.

1 HISTORY OF HYDROPONICS - O MUNDO DA HIDROPONIAhydor.eng.br/HISTORIA/C1-I.pdf · History of...

Documents

Transcript of 1 HISTORY OF HYDROPONICS - O MUNDO DA HIDROPONIAhydor.eng.br/HISTORIA/C1-I.pdf · History of...