Today, aquaponics is recognised as one of the most exciting and productive food systems available. However, we still don’t know nearly enough about the complex interactions going on in these systems, and how to maximise them. That’s why we are so keen to collect and share data about our system, so that we can contribute to developing better and better systems, that produce more from less, and waste as little as possible!
Aquaponics was re-discovered in the early ’70s by visionaries such as The New Alchemy Group, and picked up on by serious scientists at the North Carolina State University in the mid ’80s. By 1997 an academic journal was being published and interest grew rapidly.
Contemporary researchers are marvelling at the intricacy and year-round productivity of traditional aquaponics systems. For example. the Mexican Chinampas and raised-beds of Llanos de Moxos in Bolivia could feed 50 persons per Hectare without any machinery, oil, patents, waste or disease. Sadly these were destroyed by colonisation.
The Asian paddy/fish culture has fortunately continued unhindered over the centuries, and today governments are actively expanding it’s use in rural areas with outstanding results.
All these ancestral techniques relied on the diverse ecosystems and on-site waste recycling that provided life and nutrient rich waters that in turn fed plants, reduced soil erosion and controlled pests in any climate where frosts aren’t frequent.
Chinampas in Mexico
“And when we saw all those cities and villages built in the water and other great towns on dry land, and that straight and level causeway leading to Tenochtitlan, we were amazed…Indeed, some of our soldiers asked if it was not all a dream” (Spanish chronicler, Bernal Diaz del Castillo)
Chinampas were Mayan and Aztec land-creating and food growing systems of raised fields on man-made islands in the middle of lakes, marshes and floodplains of the valley of Mexico.
Chinampas consist of wattle boxes or reed fences anchored in lake, marsh and floodplain bottoms, from 6mx2m up to 100mx10m in size. These boxes were filled with layers of lake sediment and green manures like grass, leaves, shells, aquatic plants and other materials until a finger-shaped island was created, leaving 1m deep canals that allowed access with canoes. Each chinampa was secured by the roots of willow trees that were planted on the edges, and even houses were built on them.
These systems’ abundant bounty is produced by a diverse array of interactions between fish, birds, shrimps and crayfish, worms, reptiles, amphibians, micro-organisms and plants that thrive with water abundance, allowing all-year round growing of virtually everything you can think of. Back in the 14th century, the valley of Mexico hosted over 1.5 million habitants whose food supply was provided in the 1200km² chinampa network, and it has been estimated that ten thousand hectares of intensively managed chinampas would be sufficient to feed at least half-a-million people.
It is very important to highlight that the most productive systems are aquatic, thanks to water’s “universal solvent” quality and the fact that life is based on water.
Permaculture advocates and universities are bringing chinampas back to the future because of its many benefits in terms of efficiency, yield, and diversity encouragement. We are hoping to see demonstration sites of chinampas covering the range of climates Central American cultures once did. Backyard PVC contained versions are being developed in Mexico.
Llanos de Moxos, Bolivia
Similar land management solutions to the Mexican chinampas can be found in Los Llanos de Moxos, in the Beni region of Bolivia. Once again, conquistadors overwhelmed the indigenous peoples and progressively enslaved them, introducing European methods of agriculture and architecture over the centuries in one of the most catastrophic colonialism episodes in history.
One major difference between the Mexican chinampas and Amazonian savannah raised-beds is that the first ones receive water continuously and the latter receive water once annually over the period of a long wet season. It is thought that the Beni once housed some of the densest populations and the most elaborate cultures in the Amazon. These populations permanently transformed regional ecosystems, creating what Clark Erickson has referred to as a “richly patterned and humanized landscape… one of the most remarkable human achievements on the continent”.
The agricultural fields, or platforms, can vary greatly in terms of size but for the most part they were elongated and rectangular in shape, spaced anywhere from ten to a hundred feet apart and ranging from one to twenty five meters in width. Some of the larger fields extend to over three hundred meters in length.
Smaller raised platforms typically occur in groups between several hundred and several thousand individual, sometimes interconnected, bodies. Interestingly while some fields are in parallel alignments, others angle off obliquely. These varying features have been interpreted as relating to the direction of natural flow of the water, or to unknown customs regarding sacred alignments. All in all there are tens of thousands of raised fields extending across the vast, flat landscape, highly indicative of large, well-organized populations.
Judging by the overarching logic and intelligence behind the greater system it is unlikely that the populations produced and accumulated waste, as is typical of western cultures. Instead it appears as if waste was synonymous with building materials, fertilizers and other structural components. The composition of raised beds, causeways and fish weirs suggest that primarily “trash” served as a vital construction material (remind anyone of eco-houses made of old tyres?)
Other highly impressive earthworks discoveries are the many complex networks of linear zigzag structures that probably functioned both as levees and fish weirs, used seasonally to capture and contain both water and edible water fauna.
Apatani in Eastern India
The Apatani people of Eastern India have developed a multi-purpose water management system, which integrates land, water and farming systems by protecting against soil erosion, conserving water for irrigation and paddy-cum-ﬁsh culture. It is managed by diverting streams originating in the forest into a single canal to which each ﬁeld is connected with bamboo or pine wood pipe. The streams are trapped into a major channel and again redistributed to numerous secondary channels to convey water in each and every ﬁeld plots. The water is conveyed from one terrace to another through the bamboo or wooden pipes put above 15 – 25cm above the bed to ensure the proper water level. In order to contain soil erosion, bio-fencing is installed alongside of the main canals.
The irrigation systems are managed by a group of farmers led by Bogo Ahtoh (village council) to ensure proper supply and sharing of water. Paddy ﬁelds terrace are developed with size ranges from 235 to 2740m² which are levelled uniformly to ensure the uniform water height. In order to hold the water level dykes or bund, supported by bamboos and wooden clips, are constructed in the ﬁelds. The width of the dykes ranges from 0.6m to 1.4m and height varies between 0.2m to 0.6m. No ploughing is done in the ﬁeld to retain the soil fertility and land is prepared with the help of spades. The household’s waste water drained to the irrigation canals provides good source of manure in the ﬁeld. Soil nutrients are also maintained through recycling of agricultural wastes, paddy straw, rice husk, ash, weeds, etc.
After the harvest free cattle grazing is allowed to add green manure. In addition, the decomposed leaf litter leaching from the forest ﬂoor is collected in separate pipes connected to the main canal so that it goes on to the plots.
Sources for this page include Spencer Woodard and Charles C. Mann. Some of the words are theirs; all of the mistakes are ours.