The Tidal Irrigation and Electrical System

renewable energy, carbon dioxide sink, biodiesel, and food from the ocean

Water and Soil – not just Oil

Posted by on Sunday, July 27th, 2008

The concept of peak oil does not only encompass the end of cheap fuel for transport, it also spells the end of cheap food and water. 

By the late 18th century, minds were already turning to the problems of too many mouths to feed given the agricultural technology of the time. Malthusian predictions of population crash and civil disorder due to our inability to produce food faster than our population grows have emerged with a fair degree of regularity ever since. We have developed new strains of crops and this plays a part in meeting our need for food, but this is tiny compared to the new technologies that supply water and nutrients to the plants and those that transport the food to the populace at large before it rots.  Thankfully the final components in plant growth i.e. sun light, appropriate temperature fluctuation and atmospheric composition, have never been an issue for modern humanity to face. The technological developments have been varied: some simple, like crop rotation and the mining and applying to the land of ancient deposits of bat guano, and some industrial, like freezing, pumping, mechanization and chemical fertilizer.  

Despite the advances of plant breeding and the development of genetic modification, the reality is that increasingly, we have relied on techniques which are energy intensive to produce the food on which all live – and energy generally means fossil fuels. There is a wonderful letter in the New Scientist that illustrates the problem:

Peak soil 25 June 2008

John Chambers, Banbury, Oxfordshire, UK

William Stanton observed that, as oil is needed to work the farm machinery and natural gas is needed to produce the synthetic fertiliser used in grain production, the phenomena of “peak oil” and “peak gas” will inevitably lead to “peak grain” (31 May, p 23). The amounts of energy involved are indeed huge: it takes at least 35 megajoules to produce each kilogram of nitrogen in synthetic fertilisers, and 80 million tonnes of such fertiliser is used globally each year.

There are, however, yet more risks to grain production: 70 per cent of the world’s water use is in the irrigation of arable land. About 1000 tonnes of water is required to produce 1 tonne of grain. Much of this is drawn from underground aquifers – and these are close to depletion in parts of central Asia, the Middle East, north Africa, India, Pakistan and the US. Drill holes in excess of 1 kilometre deep are not uncommon, but to lift 1000 tonnes of water over that distance requires at least 9.8 gigajoules.

Grain is grown in soil, but 65 per cent of all soil on Earth shows signs of degradation such as erosion, desertification or salinisation. Over 300 million hectares of former agricultural land is now too degraded to produce food, and a further 10 million hectares become degraded or damaged every year.

“Peak soil” is long gone.

From issue 2662 of New Scientist magazine, 25 June 2008, page 24.

Biofuels grown on the land are not the solution. When factoring in the total energy that we consume in the agricultural process, biofuels generally fail to be worth the effort; you lose more energy than create and of course the water problem can only partially be fixed by pouring more energy into extracting it from the ocean or the ground. Even the use of the waste from crops for biofuels should be carefully considered before large scale implementation. The issue is about the nutrients that are represented by the waste being taken away from the soil. Traditionally crop waste is left to rot or to be eaten by animals which break down the plants for return to the soil and use by the following crop. As it is, this system is liable to exhaust the soil eventually. The nutrients that are locked up in the food we consume are removed and not returned to the land. Biofuels using crop waste will only exacerbate the problem by removing the nutrients represented in the form of stalks and leaves for use as fuel. 

The only solution is to find a new way to generate fertilizer. The Tidal Irrigation and Electrical System can do this by bringing deep ocean water (DOW) into its lagoon. The water in the deep ocean contains the vast majority of decomposed bodies of all the things that ever lived on the land or in the sea. It is the perfect medium for plant growth, and were it not for the salt we could spray it directly onto our crop lands and expect phenomenal growth. Kelp makes an excellent fertilizer and has been used for many centuries and grows, like all marine plants, extremely quickly in the presence of DOW. (See Algae/Marine Plants

There is a wonderful example of a natural process which moves DOW from the ocean to high up into the mountains where it fertilizes an entire forest ecosystem. Certain ocean currents and winter brings DOW to the surface in the pacific northwest and consequently marine plants bloom and these plants go on to feed the animals. Salmon sit near the top of the food chain in that part of the ocean and as such each one of them represents a large concentration of nutrients like iron and nitrogen. As they move up the rivers into the mountains to spawn they are heavily preyed and scavenged upon. The eagles, bears and vultures move on to their respective wider territories which extend for hundreds of square miles beyond the river. There they spread manure (which is fertilizer) far and wide. Eventually they die and their bodies are scavenged spreading the nutrients even farther across the Rockies. 

The TIE System can create the source material for fertilizer on a vast industrial scale as well as help alleviate some of the fresh water problems we are facing. A product of the OTEC subsystem is thousands of gallons of fresh water. Pipes made cold by DOW condense water out of the atmosphere when exposed to tropical air. The TIE System does all this without aggravating the problems of land-based agriculture. 


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