Truth: GM crops are energy-hungry

Myth at a glance

Industrial chemically-based agriculture is heavily dependent on energy from fossil fuels, which are in decline. In spite of claims that GM crops will reduce energy consumption due to a decreased need for pesticides and ploughing, GM crops have increased overall pesticide use and the spread of herbicide-resistant superweeds has forced farmers back to ploughing and spraying greater quantities of complex mixtures of herbicides. Thus GM crops are energy-hungry.

Proven methods of reducing the amount of fossil energy used in farming include minimizing pesticides and fertilizer use, planting leguminous crops to fix nitrogen in the soil, using agroecological techniques to manage soil fertility and control pests, and favouring human labour over fossil fuel-dependent machinery.

In experiments in the US, energy inputs for organic animal and organic legume farming systems have been found to be 28% and 32% less than those of the conventional chemically-based system. Organic, low-input, and agroecological farming is well suited to the Global South, with yields doubling in one experiment simply from the introduction of composting.

In the US food system, to produce 1 kilocalorie of plant protein requires an input of about 2.2 kilocalories of fossil energy. The average fossil energy input for animal protein production is 25 kilocalories per 1 kilocalorie of protein produced – more than 11 times greater than that for grain protein production.1,2 The major fossil energy inputs for grain, vegetable, and forage production include fertilizers, agricultural machinery, fuel, irrigation, and pesticides.2

There is widespread agreement that the energy consumption of agriculture must be radically reduced. Graham Brookes and Peter Barfoot, directors of PG Economics, a consultancy firm to the agrochemical and biotechnology industry, claim that GM crops can help to achieve that aim.3 They cite savings in tractor fuel due to two factors:

  • Less frequent herbicide or insecticide applications on GM crops
  • The no-till farming method that is used in the cultivation of GM Roundup Ready crops. The idea is that because weeds are controlled with herbicides and not with ploughing, no-till reduces the number of tractor passes that farmers have to make across their fields.3

However, these claims do not stand up to scrutiny. Although no-till reduces tractor fuel use, this saving is cancelled out by the fossil fuel used in herbicide production. Data from Argentina comparing the energy used in growing GM Roundup Ready soy and non-GM soy confirm that, while no-till did reduce farm operations (tractor passes across the field), the production of GM soy required more energy in both no-till and tillage systems. The reason for the increase was the large amount of energy consumed in the production of herbicides (mostly Roundup) used on GM soy.4

In addition, GM crops lead to increased overall pesticide use, and the incidence of herbicide-resistant superweeds is rapidly increasing. Both trends undermine the utility of herbicide-tolerant crops in no-till (see Myth 5.2 and Myth 5.5).

Proven methods of reducing the amount of fossil energy used in farming include minimizing the use of synthetic pesticides and fertilizers, maximizing the use of leguminous crops to fix nitrogen in the soil, switching from annual to perennial crops, limiting irrigation, using agroecological techniques to manage soil fertility and control pests, and replacing fossil-fuel-dependent machinery with human and animal labour and technologies to harness renewable energy.5Feeding livestock animals only on good-quality pasture instead of keeping them in intensive feedlots reduces energy inputs by about half.2

A study carried out at the Rodale Institute in the US found that energy inputs for organic animal and organic legume farming systems were 28% and 32% less than those of the conventional chemically-based system.6

Organic, low-input, and agroecological farming is well suited to the Global South. A study in Ethiopia, part-funded by the UN Food and Agriculture Organization (FAO), investigated the effect on the yields of seven cereal and two pulse crops of three different fertilization systems: compost, chemical fertilizer, and a control system with no inputs.7

The study found that compost applications doubled cereal crop grain yields in eight out of the nine crops tested, compared with the no-input control system. The use of compost also gave higher yields than the use of chemical fertilizer, though differences in the yields from compost and from chemical fertilizer were not as great as the differences between the use of compost and the control system. For sorghum and faba bean, the yields from the use of compost and chemical fertilizer were similar. But the yield difference for all the other crops was greater, with the yield from the compost treatment being always higher than that from the use of chemical fertilizer.7

The crops grown with compost had better resistance to pests and disease and there were fewer difficult weeds; soil fertility was also restored in this system.7

Peak oil and gas mean GM crops are unsustainable

According to some analysts, peak oil – the point when the maximum rate of extraction is reached, after which production goes into terminal decline – has already arrived, with peak gas expected around 2020.8 Peak oil and gas mark the end of chemically-based agriculture because nitrogen fertilizers are synthesized using large amounts of natural gas, and pesticides (including herbicides) are made from oil.

GMO firms constantly promise new GM crops that are not reliant on the chemical model of farming, but GM technology is simply not capable of creating the complex traits that would fulfil this promise, such as more efficient nitrogen utilization. Furthermore, GM companies are agrochemical companies. Their business model is built on increasing the use of chemical pesticides and fertilizers. The 80% of GM crops that are herbicide-tolerant are designed to be grown with high doses of fossil fuel-hungry herbicide. Many of the newest GM crops are engineered to tolerate several different herbicides (see Myth 5.2).

Agriculture cannot continue to depend on non-renewable and increasingly expensive external inputs. Future food production systems will reduce or eliminate pesticide use and rely on renewable biologically-based fertilizers – such as compost and animal manure – produced on the farm or locally.

“We have tried to have more efficient farming, with fewer people, more machines and a greater dependency on pesticides, fertilizers, GM crops and energy, using 10 kilocalories to produce one kilocalorie [of food delivered to the consumer]. But that is only possible if there is cheap oil. The system basically is bankrupt, which is why we need to change it to a more modern, advanced system, which will create energy, rather than consume it, and is not dependent on fossil energy, but more on people and better science.”
– Dr Hans Herren, president of the Millennium Institute (Washington, DC, USA) and co-chair, International Assessment of Agricultural Knowledge, Science and Technology, (IAASTD), a UN-, World Bank-, and WHO-sponsored project on the future of farming involving more than 400 experts from across the world9

Conclusion

Claims that GM crops will reduce energy consumption due to a decreased need for pesticides and ploughing are incorrect. GM crops have increased overall pesticide use and the spread of herbicide-resistant superweeds has forced farmers back to ploughing and spraying even greater quantities of complex mixtures of herbicides. The production of herbicides uses large quantities of fossil energy. Thus GM crops are energy-hungry.

Proven methods of reducing the amount of fossil energy used in farming include minimizing pesticides and fertilizer use, planting leguminous crops to fix nitrogen in the soil, using agroecological techniques to manage soil fertility and control pests, and favouring human labour over fossil fuel-dependent machinery.

In experiments in the US, energy inputs for organic animal and organic legume farming systems have been found to be 28% and 32% less than those of the conventional chemically-based system. Organic, low-input, and agroecological farming is well suited to the Global South, with yields doubling in one experiment simply from the introduction of composting.

References

  1. Pimentel D, Doughty R, Carothers C, Lamberson S, Bora N, Lee K. Energy use in developing and developed crop production. In: Lal R, Hansen D, Uphoff N, Slack S, eds. Food security and environmental quality in the developing world. Boca Raton, FL: CRC Press; 2002:129–51.
  2. Pimentel D, Pimentel M. Sustainability of meat-based and plant-based diets and the environment. Am J Clin Nutr. 2003;78(3):660S-663S.
  3. Brookes G, Barfoot P. Global impact of biotech crops: Socio-economic and environmental effects in the first ten years of commercial use. AgBioForum. 2006;9:139–151.
  4. Bindraban PS, Franke AC, Ferrar DO, et al. GM-related sustainability: Agro-ecological impacts, risks and opportunities of soy production in Argentina and Brazil. Wageningen, the Netherlands: Plant Research International; 2009. Available at: http://bit.ly/Ink59c.
  5. Pimentel D, Pimentel M. Food, Energy and Society. Niwot, CO: University Press of Colorado; 1996. Available at: http://www.amazon.com/Food-Energy-Society-David-Pimentel/dp/0870813862.
  6. Pimentel D, Hepperly P, Hanson J, Douds D, Seidel R. Environmental, energetic, and economic comparisons of organic and conventional farming systems. Bioscience. 2005;55:573–582.
  7. Edwards S, Asmelash A, Araya H, Egziabher TBG. Impact of compost use on crop yields in Tigray, Ethiopia. Rome, Italy: Natural Resources Management and Environment Department, Food and Agriculture Organization of the United Nations; 2007.
  8. Mobbs P. In: Energy Beyond Oil. Trowbridge, Wiltshire, UK: Cromwell Press; 2005:54.
  9. Driver A. CropWorld Global 2011: Changing our global approach to farming. Farmers Guardian. http://bit.ly/LXmk2s. Published September 1, 2011.