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COPYRIGHT 2002 Journal of Business Administration
INDUSTRIAL AGRICULTURE AND BIODIVERSITY
Agriculture implies the simplification of nature's biodiversity and reaches an extreme form in crop monoculture. The end result is the production of an artificial ecosystem requiring constant human intervention. In most cases, this intervention is in the form of agrochemical inputs which, in addition to boosting yields, result in a number of undesirable environmental and social costs (Altieri, 1995).
Global threats to biodiversity should not be foreign to agriculturalists, since agriculture, which covers about 25-30% of the world land area, is perhaps one of the main activities affecting biological diversity. It is estimated that the global extent of cropland increased from around 265 million hectares in 1700 to around 1.5 billion hectares today, predominantly at the expense of forest habitats. Very limited areas remain totally unaffected by agriculture-induced land use changes (McNeely and Scherr 2003).
Clearly, agriculture implies the simplification of the structure of the environment over vast areas, replacing nature's diversity with a small number of cultivated plants and domesticated animals. In fact, the world's agricultural landscapes are planted with only some 12 species of grain crops, 23 vegetable crop species, and about 35 fruit and nut crop species; that is no more than 70 plant species spread over approximately 1,440 million has of presently cultivated land in the world. This is in sharp contrast with the diversity of plant species found within one hectare of a tropical rainforest which typically contains over 100 species of trees. Of the 7,000 crop species used in agriculture, only 120 are important at a national level. An estimated 90% of the world's calorie intake comes from just 30 crops, a small sample of the vast crop diversity available (Jackson and Jackson 2002).
The process of biodiversity simplification associated with industrial agriculture can affect biodiversity in various ways:
* Expansion of agricultural land with loss of natural habitats
* Conversion into homogenous agricultural landscapes with low habitat value for wildlife
* Loss of wild species and beneficial agrobiodiversity as a direct consequence of agrochemical inputs and other practices
* Erosion of valuable genetic resources through increased use of uniform high-yielding varieties
As the industrial model was introduced into the developing world, agricultural diversity has been eroded as monoculture has started to dominate. For example, in Bangladesh the promotion of Green Revolution rice led to a loss of diversity including nearly 7,000 traditional rice varieties and many fish species. Similarly in the Philippines, the introduction of HYV rice displaced more than 300 traditional rice varieties. In the North similar losses in crop diversity is occurring. Eighty-six percent of the 7,000 apple varieties used in the U.S. between 1804 and 1904 are no longer in cultivation; of 2,683 pear varieties, 88% are no longer available. In Europe thousands of varieties of flax and wheat vanished following the take-over by modernvariants (Lipton and Longhurst 1989).
MODERN AGRICULTURE, GENETIC HOMOGENIZATION AND ECOLOGICAL VULNERABILITY
Modern agriculture is shockingly dependent on a handful of varieties for its major crops. For example, in the U.S. two decades ago, 60 to 70% of the total bean acreage was planted with two to three bean varieties, 72% of the potato acreage with four varieties, and 53% with three cotton varieties (National Academy of Sciences, 1972). Researchers have repeatedly warned about the extreme vulnerability associated with this genetic uniformity. Perhaps the most striking example of vulnerability associated with homogenous uniform agriculture was the collapse of Irish potato production in 1845, where the uniform stock of potatoes was highly susceptible to the blight, Phytophthora infestans infestans. During the 19th century in France, wine grape production was wiped out by a virulent pest, Phylloxera vitifoliae, which eliminated 4 million hectares of uniform grape varieties. Banana monocultural plantations in Costa Rica have been repeatedly seriously jeopardized by diseases such as Fusarium oxysporum and yellow sigatoka. In the USA, in the early 1970s, uniform high-yielding maize hybrids comprised about 70% of all the maize varieties; a 15% loss of the entire crop by leaf blight occurred in that decade. A worrisome trend is the recent expansion of transgenic maize and soybean monoculture mostly grown in the US which has reached about 45 million hectares in less than 6 years.
Modern agroecosystems are unstable, and breakdowns manifest themselves as recurrent pest outbreaks in most cropping systems. The worsening of most pest problems has been experimentally linked to the expansion of crop monoculture at the expense of vegetation diversity. This diversity is a key landscape component providing crucial ecological services to ensure crop protection through provision of habitat and resources to natural pest enemies (Altieri 1994). Ninety-one percent of the 1.5 billion hectares of cropland worldwide are under annual crops are planted with mostly monocultures of wheat, rice, maize, cotton, and soybeans. One of the main problems arising from the homogenization of agricultural systems is an increased vulnerability of crops to insect pests and diseases, which can be devastating if they infest a uniform crop, especially in large plantations. To protect these crops, copious amounts of increasingly less effective and selective pesticides are injected into the biosphere at considerable environmental and human costs. These are clear signs that the pesticide-based approach to pest control has reached its limits. An alternative approach is needed; one based on the use of ecological principles in order to design more sustainable farming systems that take full advantage of the benefits of biodiversity in agriculture.
THE EXPANSION OF MONOCULTURE IN NORTH AMERICA
Today, monoculture has increased dramatically worldwide, mainly through the geographical expansion of land devoted to single crops and year-to-year production of the same crop species on the same land. Available data indicate that the amount of crop diversity per unit of arable land has decreased and that croplands have shown a tendency toward concentration. There are political and economic forces influencing the trend to devote large areas to monoculture and, in fact, such systems are rewarded by economies of scale and contribute significantly to the ability of national agricultures to serve international markets.
The technologies which have facilitated the shift toward monoculture are mechanization, the improvement of crop varieties, and the development of agrochemicals to fertilize crops and control weeds and pests. Government commodity policies these past several decades have also encouraged the acceptance and utilization of these technologies. As a result, farms today are fewer, larger, more specialized and more capital-intensive. At the regional level, the increase in monoculture farming has meant that the entire agricultural support infrastructure (i.e. research, extension, suppliers, storage, transport, markets, etc.) has become more specialized.
From an ecological perspective, the regional consequences of monoculture specialization are many-fold:
a) Most large-scale agricultural systems exhibit a poorly structured assemblage of farm components, with almost no linkages or complementary relationships between crop enterprises and among soils, crops and animals.
b) Cycles of nutrients, energy, water and wastes have become more open, rather than closed as in a natural ecosystem. Despite the substantial amount of crop residues and manure produced in farms, it is becoming increasingly difficult to...
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