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6. OTHER ASPECTS OF GM FOODS

ECOLOGICAL INTENSIFICATION OF CEREAL PRODUCTION SYSTEMS: YIELD POTENTIAL, SOIL QUALITY, AND PRECISION AGRICULTURE

The following points are made by Kenneth G. Cassman (Proc. Nat. Acad. Sci. 1999 96:5952):

1) Wheat (Triticum aestivum L.), rice (Oryza sativa L.), and maize (Zea mays L.) provide about two-thirds of all energy in human diets, and four major cropping systems in which these cereals are grown represent the foundation of human food supply.

2) Yield per unit time and land has increased markedly during the past 30 years in these systems, a result of intensified crop management involving improved germplasm, greater inputs of fertilizer, production of two or more crops per year on the same piece of land, and irrigation.

3) Meeting future food demand while minimizing expansion of cultivated area primarily will depend on continued intensification of these same four systems. The manner in which further intensification is achieved, however, will differ markedly from the past because the exploitable gap between average farm yields and genetic yield potential is closing. At present, the rate of increase in yield potential is much less than the expected increase in demand. Hence, average farm yields must reach 70-80% of the yield potential ceiling within 30 years in each of these major cereal systems.

4) Achieving consistent production at these high levels without causing environmental damage requires improvements in soil quality and precise management of all production factors in time and space. The author concludes that major scientific breakthroughs must occur in basic plant physiology, ecophysiology, agroecology, and soil science to achieve the ecological intensification that is needed to meet the expected increase in food demand.(1-5)

References (abridged):

1. Poster, S. L. (1998) BioScience 48, 629-637

2. Waggoner, P. E. (1994) How Much Land Can Ten Billion People Spare for Nature (Council for Agricultural Science and Technology, Ames, IA)

3. Mason, P. R., Parton, W. J., Power, A. G. & Swift, M. J. (1997) Science 277, 504-509

4. Vitousek, P. M., Mooney, H. A., Lubchenco, J. & Melillo, J. M. (1997) Science 277, 494-499

5. Rosegrant, M. W., Leach, N. & Gerpacio, R. V. (1998) Alternative Futures for World Cereal and Meat Consumption (International Food Policy Institute, Washington, DC)

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THE TRANSITION TO AGRICULTURAL SUSTAINABILITY

The following points are made by Vernon W. Ruttana (Proc. Nat. Acad. Sci. 1999 96:5960):

1) The institutional and cultural foundations of the modern world began to emerge in Western Europe in the 17th and 18th centuries. The material basis for the agricultural and industrial revolutions was established during the 18th and 19th centuries. These advances were initially limited to a few countries in western Europe and their offshoots. For most countries of the world, the transition did not begin until well into the 20th century. These institutional and technical changes combined to generate unprecedented growth in population, in resource use, and in human welfare. Since mid-century alone, global population has doubled, energy production has more than tripled, and economic output has increased by a factor of five.

2) The challenge of the 21st century will be to make the transition to sustainable growth in both presently developed and low income countries. It will involve a transition to a stable global population, it may involve a transition to a stable level of material consumption, and it will involve a transition to a largely urban society. Whether the transition will be accompanied by levels of material and energy consumption in presently poor countries comparable to the levels that have been achieved by the industrial countries is the subject of intense debate. How much land will be left to nature after meeting the demands for agricultural commodities and the demands for environmental services arising out of population and income growth is even more problematical.

3) It is possible, within another decade, that advances in molecular biology and genetic engineering will reverse the urgency of concerns about food production. The use of genetic engineering is enabling plant breeders to manipulate genetic materials with greater precision and to speed the pace of crop breeding. The applications of genetic engineering that are presently available in the field, however, are primarily in the area of plant protection and animal health. They are enabling producers to push crop and animal yields toward their genetic potential, but they have not yet raised the biological ceilings above the levels that have been achieved by researchers employing the older methods based on Mendelian biology. The advances that are most likely to be introduced over the next decade are likely to be the result of efforts to realize higher value, e.g., from nutriceuticals and pharmaceuticals, rather than from efforts to break the constraints on yield ceilings. The excessively broad patent rights being granted in the field of biotechnology may become a serious institutional constraint on the transfer of plant protection and animal health biotechnology products to farmers in developing countries.

4) In summary: The transition to sustainable growth in agricultural production during the 21st century will take place within the context of a transition to a stable population and a possible transition to a stable level of material consumption. If the world fails to successfully navigate a transition to sustainable growth in agricultural production, the failure will be due more to a failure in the area of institutional innovation than to resource and environmental constraints.(1-5)

References (abridged):

1. National Research Council. (1999) A Common Journey: Toward a Sustainability Transition. (National Academy Press, Washington, DC), in press.

2. Hammond, A. (1998) Which World? Scenarios for the 21st Century (Island, Washington, DC)

3. Raskin, P., Gallopin, G., Gutman, P., Hammond, A. & Swart, R. (1998) Bending the Curve: Toward Global Sustainability (Stockholm Environment Institute, Stockholm)

4. Lele, S. (1991) World Dev. 19, 607-621

5. Ruttan, V. W. (1994a) Ecol. Econ. 12, 209-219

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HUMAN DOMINATION OF EARTH'S ECOSYSTEMS

The following points are made by P.M. Vitousek et al (Science 1997 277:494):

1) All organisms modify their environment, and humans are no exception. As the human population has grown and the power of technology has expanded, the scope and nature of this modification has changed drastically. Until recently, the term "human-dominated ecosystems" would have elicited images of agricultural fields, pastures, or urban landscapes; now it applies with greater or lesser force to all of Earth. Many ecosystems are dominated directly by humanity, and no ecosystem on Earth's surface is free of pervasive human influence.

2) The growth of the human population, and growth in the resource base used by humanity, is maintained by a suite of human enterprises such as agriculture, industry, fishing, and international commerce. These enterprises transform the land surface (through cropping, forestry, and urbanization), alter the major biogeochemical cycles, and add or remove species and genetically distinct populations in most of Earth's ecosystems. Many of these changes are substantial and reasonably well quantified; all are ongoing. These relatively well-documented changes in turn entrain further alterations to the functioning of the Earth system, most notably by driving global climatic change (1) and causing irreversible losses of biological diversity (2).

3) The use of land to yield goods and services represents the most substantial human alteration of the Earth system. Human use of land alters the structure and functioning of ecosystems, and it alters how ecosystems interact with the atmosphere, with aquatic systems, and with surrounding land. Moreover, land transformation interacts strongly with most other components of global environmental change.

4) The measurement of land transformation on a global scale is challenging; changes can be measured more or less straightforwardly at a given site, but it is difficult to aggregate these changes regionally and globally. In contrast to analyses of human alteration of the global carbon cycle, we cannot install instruments on a tropical mountain to collect evidence of land transformation. Remote sensing is a most useful technique, but only recently has there been a serious scientific effort to use high-resolution civilian satellite imagery to evaluate even the more visible forms of land transformation, such as deforestation, on continental to global scales (3).

5) Land transformation encompasses a wide variety of activities that vary substantially in their intensity and consequences. At one extreme, 10 to 15% of Earth's land surface is occupied by row-crop agriculture or by urban-industrial areas, and another 6 to 8% has been converted to pastureland (4); these systems are wholly changed by human activity. At the other extreme, every terrestrial ecosystem is affected by increased atmospheric carbon dioxide (CO2), and most ecosystems have a history of hunting and other low-intensity resource extraction. Between these extremes lie grassland and semiarid ecosystems that are grazed (and sometimes degraded) by domestic animals, and forests and woodlands from which wood products have been harvested; together, these represent the majority of Earth's vegetated surface.(5)

References (abridged):

1. Intergovernmental Panel on Climate Change, Climate Change 1995 (Cambridge Univ. Press, Cambridge, 1996), pp. 9-49

2. United Nations Environment Program, Global Biodiversity Assessment, V. H. Heywood, Ed. (Cambridge Univ. Press, Cambridge, 1995)

3. D. Skole and C. J. Tucker, Science 260, 1905 (1993)

4. J. S. Olson, J. A. Watts, L. J. Allison, Carbon in Live Vegetation of Major World Ecosystems (Office of Energy Research, U.S. Department of Energy, Washington, DC, 1983)

5. P. M. Vitousek, P. R. Ehrlich, A. H. Ehrlich, P. A. Matson, Bioscience 36, 368 (1986) ; R. W. Kates, B. L. Turner, W. C. Clark, in (35), pp. 1-17; G. C. Daily, Science 269, 350 (1995) . D. A. Saunders, R. J. Hobbs, C. R. Margules, Conserv. Biol. 5, 18 (1991)

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ON BIOTECHNOLOGY AND FUTURE WORLD FOOD PRODUCTION

The consumption of nutrients is one of the main activities of all living systems, and the development and improvement of production of nutrient sources ("food") has been one of the main activities of the human species throughout its history. It is generally believed that the application of new techniques in molecular biology and genetics to agriculture will be of great importance to our species in the next century, and indeed that application is already underway and essentially constitutes the beginnings of a revolution in the technology of nutrient production. Technological revolutions, however, are hardly ever without opponents, people made uneasy by the idea of change and the possible risks of change. Indeed, the risks are sometimes severe, involving social and economic upheavals in large populations. These days, one focus of such opposition to change is the introduction of new methods in agricultural technology, particularly the application of genetic engineering techniques to crop production. At the present time in human history, the prime movers in applied science are in the commercial sector, profit-making enterprises that essentially put up the capital required for applied science in order to bring a return on the investment to their shareholders. That is our current system, and in the context of agricultural technology, it is to be expected that those corporate enterprises responsible for the application of genetic engineering to agriculture will bear the brunt of vocal opposition generated by fears of technological innovation. One corporate enterprise that has received a good deal of that brunt is the Monsanto Company, a leader in the application of genetic engineering in agriculture worldwide. Today, in the United Kingdom, protesters wreck experimental crops designed to improve food production; in 1815, in the same region, protesters wrecked the new machines of the Industrial Revolution designed to improve the production of cloth and other goods.

G.M. Kishore and C. Shewmaker (PNAS 1999 96:5968) present a review of the application of biotechnology to improve human nutrition in developing and developed regions of the world, the authors making the following points:

1) Since the beginning of this century, agriculture has intensified with a) the discovery of economical chemical processes to reduce nitrogen to ammonia and the use of nitrogenous fertilizers; b) superior genetics with hybrid as well as varietal crops; c) the discovery and use of chemical pesticides to manage weeds, microbes, and insects.

2) Over the past 50 years, society has faced the challenge of feeding an ever-growing world population. Human population has literally doubled in the last 40 years and increased 6-fold in the last 200 years. The challenge over the next 50 years will be to not only feed more people, but to do so in a manner which takes into account probabilities such as the following:

a) There will be less arable land. A combination of overplowing, overgrazing, and deforestation has caused soil erosion to exceed soil formation. Countries particularly hard hit are those in continents like Africa, where soil is shallow to begin with. The next generation of farmers in Africa will need to feed not the 719 million people of today, but the 1.45 billion people in the year 2025.

b) There will be fewer resources, particularly nonrenewable resources such as phosphorus and potassium, which are used in fertilizers. While it can be argued that we have sufficient natural deposits of these minerals to last another 200 years, technologies that minimize ore extraction and dispersion over vast areas of land will enhance the sustainability of our agricultural systems.

c) There will be less water, and the quality of remaining water will be reduced as demand increases. Water use has tripled since mid-century, and water tables are falling around the world. Seventy percent of all the water pumped from underground or drawn from rivers is used for irrigation, and if we face a future of water scarcity, we also face a future of food scarcity.

d) Fewer people will engage in primary agriculture in both developed and developing countries. In the US, less than 1 percent of the population is engaged in primary agriculture, compared with 60 percent of the population in the early 1900s.

3) Biotechnology is a discipline that has developed rapidly during the last two decades. This technology is based on the ability to introduce precise genetic changes into an organism. Plant biotechnology, in particular, has evolved rapidly over the course of the last 15 years. Every major crop can be subject to precise genetic modifications based on our ability to introduce and express genes in crops. Plant biotechnology, therefore, should substantially augment plant breeding, which until now has been based on the ability to harness genes into plants either by sexual crossing or laboratory techniques such as cell fusion.

4) Concerning the herbicide "Roundup" (a Monsanto product), and the genetic engineering of crops that resist that herbicide so the herbicide can be used to protect those same crops against weeds (it is such genetically engineered crops that have provoked militant destructive protests in the UK), the authors present the following details: "Roundup-Ready" soybeans (the genetically engineered crop) contain a gene encoding the enzyme 5-enolpyruvylshikimate 3-phosphate synthase, an enzyme which is involved in the biosynthesis of aromatic amino acids in plants. The gene for this enzyme, when the gene is naturally present in soybeans, produces a form of the enzyme sensitive to glyphosate, the active ingredient of the herbicide Roundup. In genetically engineered Roundup-Ready soybeans, the gene has been replaced by a gene that encodes a catalytically active but glyphosate-tolerant form of the same enzyme. Expression of the new gene in plants renders in those plants adequate tolerance to the herbicide, which can then be used to protect the plants from weeds.

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