No energy, no harvest
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CTA. 2000. No energy, no harvest. Spore 88. CTA, Wageningen, The Netherlands.
Permanent link to this item: http://hdl.handle.net/10568/46844
Internet URL: http://spore.cta.int/images/stories/pdf/old/spore88.pdf
The world s energy policies due for a major review by April 2001 have been very, very wrong. Food barely features in them. What shall we eat if we have nothing to harvest? There is a scientific law, the Law of Conservation of Energy, that...
The world s energy policies due for a major review by April 2001 have been very, very wrong. Food barely features in them. What shall we eat if we have nothing to harvest? There is a scientific law, the Law of Conservation of Energy, that says that the total amount of energy in the Universe is fixed energy can neither be created or destroyed, it can only change from one form to another. As far as ACP agriculture is concerned, whatever way you look at it energy inputs, energy stayputs or energy outputs the amount of energy involved is not enough. Not enough is being used to grow crops or raise livestock, and not enough is being eaten or sold to be eaten. No country, no field, no farmer is the same but, in general, the small-scale practices which dominate ACP agriculture have long followed another law, this time the economic Law of Diminishing Returns. So much effort is made through muscle power, both human and animal, that there is little more to be given; only minor design changes in handheld or animal-drawn equipment are going to squeeze any small gains in productivity. And the levels of soil replenishment, by whatever means, are too low to stop the process of soil mining , whereby a soil s fertility is not replaced by new inputs. The demand for increased food supply leads us inexorably to more intensive forms of agriculture, but not necessarily in more intensive inputs alone; we can also have more intensive care of soils and plants, and more intensive harvesting, storage and transport. They will all cost more energy. Energy is an expensive commodity, as anyone familiar with the price of oil in the second half of 2000 will testify. Yet in a context where many ACP countries must almost double their recent rises in production to above 4%, there is no real alternative to making greater and more efficient energy inputs. Each input of energy, whether fossil fuel or human muscle power, can result in wildly different outputs in different farming systems. In the heavily mechanised and fertilised fields of California, the yield of energy in the rice harvest is 1.6 times the energy input, while in the Iban region of Borneo it is 7.0 there the only input is people s labour. Does this mean victory for the low-energy input school of thought? Not necessarily, since the resulting yields per hectare are three times lower than in California: put starkly, if you can put more energy into cultivation, you can probably harvest more. Where can the additional energy come from? For much of sub-Saharan Africa, the classical answer, consistently promoted by the FAO, is to increase the use of manufactured fertiliser, and of irrigation (each of these inputs is energy dependent: inorganic fertilisers require energy to synthesise them, and energy is required to lift irrigation water. Africa s average annual fertiliser use is only 20 kg per hectare against a world average of 96 kg, and only 6% of its arable land is irrigated against a world average of 17%. To make any significant increase upon such levels of input with associated increases in mechanisation will have a tremendous impact on the energy bill, on farming practices and potentially on social structures, most notably on gender equity. Energy conservation the stayput part of the equation is a key factor. Great improvements can be made by better recycling of soil nutrients, through better tillage, inter-cropping and the use of green manures and organic fertilisers. Similarly, low-cost water inputs such as drip irrigation, and the use of direct solar and wind power for water lifting, can have great effect. Diversifying energy sources With the market ever more urban, the energy demands of harvesting, processing and transport are also set to rise sharply. It is on the way from the farm gate to market that an energy transition starts to take real shape. Such a transition to sustainable energy systems, according to FAO, would be characterised by a move from the present levels of subsistence use of energy, based on human labour, animal power and fuelwood, to situations where household, services and farming activities use diversified energy sources. A contributing factor here is the yet-to-be-calculated energy impact of the way HIV/AIDS has decimated working populations. As the mechanisation of production and processing continues, there will be a need for more small-scale equipment, and energy to power it. Similar needs are growing for water pumping and processing and storage of foods, alongside other uses in communal, educational and health facilities, not to mention the fast-spreading networks of telecentres in virtually all ACP countries. How will this be fuelled? Increasingly, the focus is on electrification powered by fossil fuels, and gas from biomass and gasification. Biogas plants fed with waste cannot meet growing and rural energy needs. More research is needed on gasification and fuels from energy sources planted for the purpose.Illustration H. Larkins The use of so-called renewable energies is finally becoming financially viable, after decades of research, and extensive outreach programmes in, for example, the Sahel, Zimbabwe and the Pacific. Another source of energy for agriculture can be agriculture itself, in the form of biomass from agricultural and forest waste, and energy crops. Bioenergy comes in many forms: biogas digesters using animal waste, gas from gasified wastes or liquid fuels, such as ethanol, distilled from sugar cane and other crops. The next step could be biomass plantations of wood for local gasification and production of commercial fuels, largely for transportation. Under the Renewables-Intensive Global Energy Scenario project of the UN Development Programme, one third of Africa s fuel needs in 2025 could be met by locally produced biofuels, using largely marginal land and with a minimal food or fuel conflict about land. Here lies an area for ecological debate and, perhaps, a business opportunity for rural entrepreneurs. Change needed in macro-policy The energy requirements of sub-Saharan agriculture could triple by 2020. That is indeed a tall order, and requires macro-policy initiatives at national and regional levels. Yet agriculture is not part of the mindset of most energy planners. In most ACP countries, it accounts for less than 4.5% of energy consumption. It is barely visible on the energy balance sheet . Clearly ACP agriculture should become part of national energy policy initiatives. Undoubtedly its potential as a supplier of bioenergy will earn more attention. A policy text on renewable energy, adopted in March 2000 by the Joint Assembly of the ACP and the European Union in Abuja, Nigeria, emphasised the key role of energy in rural development strategies. Talk of energy to a scientist, and you see the ideas spark: there are plans, well advanced, by some Western energy companies to beam concentrated solar power from space to collector panels, often in ACP countries, for transmission to the world s cities. Could part of that power stay in the locality? There are ideas, some say more than that, of producing energy through fusion techniques which extract power from controlled explosions of atoms, even in a glass of water. Fantastic? Maybe. Totally separated from ACP agriculture if not? Maybe not. Although the fruits of his fantasy are still only available to a small minority of rural populations today (8%), the scientist Michael Faraday discovered electricity over 100 years ago. He wrote then: Nothing is too wonderful to be true . So let s get agriculture onto the energy agenda. [summary points] Linking food security and energy In April 2001, the UN Commission on Sustainable Development will draw up new global guidelines for sustainable energy policies. These points of key interest to ACP agriculture (see article) are already on the agenda: diversification of energy sources security of supply rural electrification solar, wind and biomass-based technologies Biogas plants fed with waste cannot meet growing rural energy needs. More research is needed on gasification and fuels from energy sources planted for the purpose See Links on Energy Information