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ACHIEVING ECO-NOMIC SECURITY*
ON SPACESHIP EARTH

By Jim Bell

CHAPTER X
ECO-NOMIC SECURITY AND AGRICULTURE

Food Security And Population
Soil Erosion
The Development Of Agricultural Soils
Dependence On Non-renewable Energy Resources
Maintaining Genetic Diversity Of Crop Plants
Organic Agriculture
Agricultural Eco-nomics
Organic Agriculture In The Future
Organic Agriculture: Current Technologies
Agricultural Appendix
Petrochemical Agriculture: Why It Is Not Eco-nomically Sustainable
The Effect Of Pesticides On People
Herbicides: Deja Vu All Over Again
Non-toxic Weed Control
Biological Magnification
Chemical Fertilizers

 

 

 

 

 

 

 

 

Synopsis

Preserving and replenishing agricultural soils is essential to our eco-nomic security. Worldwide, agricultural soils are being lost to development and erosion. It is therefore imperative that we do everything we can to prohibit the further development of agricultural soils and adopt agricultural methods that build soil fertility instead of causing it to erode away.

Beyond protecting our soils from development and erosion, we need to develop agricultural methods that are eco-nomically sustainable. Fortunately, a number of agricultural systems are approaching eco-nomic sustainablity and their applications are growing in sophistication rapidly. In their book, Alternative Agriculture, the (U.S.) National Academy of Science highlighted a number of economically successful farms in the United States that practice organic/soil-building methods of agriculture. One 280 hector (700 acres) organic farm in Ohio has operated profitably for 15 years. In addition to having higher crop yields than any other farms in its county, its cost of production per hector is 40 percent less than the areas average.

 

 

 

 

 

 
Food Security And Population
 

 

 

 

 

 

 

 

Preserving agricultural soils and switching to organic agriculture is another way to increase eco-nomic security. After a sustainable supply of breathable air and drinkable water, having a secure supply of nutritious food is the most vital element necessary for our well-being. Whether we look globally or just at the United States, our food sustainability is in question.

If distributed equitably, there is enough food being produced to feed everyone living on our planet today. (657) Yet, even at our present level of population, researchers from the World Hunger Project at Brown University question whether we can feed a world population of 5.5 billion sustainably, considering current agro-know-how and food consumption patterns. They estimate we could feed 5.5 billion people sustainability, but only if we all adopted a vegetarian diet and food was distributed equitably. (658)

At U.S. consumption levels, of which 25 percent is animal products, the number of people that could be fed sustainably drops to just 2.8 billion according to the World Hunger Project Study. (659) This is because it takes much more land, water, and energy to grow a given quantity of meat than it does to grow an equal amount of edible plant material. It takes ten pounds of grain to produce one pound of beef.

Added to our present situation is the fact that our population is still growing steadily. "Of the 13.4 billion hectares of land area in the world, only about 11% or 1.5 billion hectares (3.7 billion acres) is considered suitable for cultivation." (660) This is less than seven-tenths of an acre per person for a world population of 5.5 billion people. If world population continues to increase at its present rate of 92 million more people per year, the nearly 8 billion person world population in the year 2020 will have less than half of an acre of quality agricultural soils per capita to grow food on. (661) This is assuming that we protect the agricultural soils we still have, something we have not done very well up to now.

 

 

 

 

 

 
Soil Erosion
 

 

 

 

 

 

 

 

In addition to population, a number of problems threaten our food security. One of the most pervasive threats to food security is the loss of agricultural soils to erosion. In parts of the Midwest (U.S)., as much as an inch of topsoil is lost to erosion every 20 years. As a whole, 2.7 to 3.1 billion tons of topsoil is lost to wind and water erosion in the U.S. each year. (662)

If a loss of 3 billion tons of topsoil per year were to continue and was uniform and continuous, all the topsoil on U.S. croplands would be washed away in less than 150 years. (663) One result of topsoil loss is that it causes crop yields to drop. Starting with a topsoil depth of 12 inches, the average per acre loss in yields per inch of soil loss is 4 bushels for corn, 2 to 4 bushels for oats, 1.6 bushels for wheat, and 2.6 bushels for soybeans. (664)

To date, energy inputs, primarily from fossil fuels, have masked the negative impact that soil erosion is having on crop production. Fossil fuels have powered a "ninefold increase in fertilizer use and the near tripling of the world's irrigated cropland since mid-century". (665)

In their book World Resources 1992-93, the World Resources Institute reported that a land area "equal to China and India combined -- has become gravely degraded since World War II". In other words, "roughly 11 percent of the planet's vegetative surface has become so damaged" from "overgrazing, agriculture, deforestation, and other human uses," --- "that restoration will be costly or impossible". (666)

It should be noted that in addition to the 3.7 billion acres of good agricultural soil on our planet, there are approximately 3.7 billion additional acres of lower quality soil that could be potentially used for agriculture. (667) But, even under the best conditions, most of these soils will only be marginally productive unless large imputes of energy are applied to them, in the form of intense fertilization, pumped irrigation water, and erosion control.

Erosion control on marginal soils is also difficult. Even if good management strategies are used, most soils are subject to some erosion but erosion control is a particular problem on marginal soils. In addition to being thin, these soils are often classified marginal because they are steeply sloped. A Nigerian study, which measured soil erosion, showed that it is more difficult to keep soil losses below levels that are sustainable when steeper slopes are cultivated. "Cassava planted on land of a 1 percent slope lost an average of 3 metric tons (3.3 U.S. tons) of soil per hectare (a hector is approximately 2.5 acres) each year, comfortably below the maximize accepted rate of soil loss tolerance of 12.5 tons per hector. (668) On a 5 percent slope, however, land planted to cassava eroded at a rate of 87 tons per hectare annually--a rate at which a topsoil layer of six inches would disappear entirely within a generation. Cassava planted on a 15 percent slope led to an annual erosion rate of 221 tons per hectare, which would remove all topsoil within a decade." (669)

"Worldwide, an estimated 25 billion tons of topsoil is being lost from cropland each year, roughly the amount that covers Australia's wheat lands." (670) Under good conditions, five tons of soil loss per acre per year or 12.5 tons per hector per year is considered the maximum soil loss that can be sustained if the plant wastes produced on the soil are returned to it. Unfortunately, this assessment is probably optimistic. Some "scientists estimate that, under agricultural management, around one inch of new topsoil will be formed every 100 to 1,000 years." (671) At a rate of one inch per 100 years, about 1.5 tons of new topsoil would be added per acre each year. (672) If this is true, the maximum loss of topsoil that can be sustained indefinitely is 1.5 tons per acre or 3.75 tons per hector per year.

Where conditions are less than ideal, the formation of soil is much slower. In areas where moisture is limited and/or growing seasons short, it may take 10,000 years for an inch of soil to form. (673)

Along with the special care and energy inputs needed to keep marginal soils productive, the cultivation of these soils would greatly increase the destruction of the wildlife communities that now inhabit these areas and the watershed function that these wild communities serve.

In addition to losing the productivity of our soils, soil erosion causes other problems. Of the up to 4 billion tons of soil reaching U.S. streams annually, "about one billion tons reach the ocean, while the other three-fourths of the sediment remains in streams, rivers, reservoirs, and lakes." (674)

Whether in coastal estuaries or fresh water environments, silt and sediment can damage spawning beds by covering vegetation or gravel beds needed by fish for egg laying and egg incubation. Other erosion-related impacts include increased flood damage which results when silt and sediment deposits restrict the flow of water in rivers and streams. Sediment laden water also makes potable water treatment more difficult and reduces water related recreational opportunities. Silt and sediment deposits cause additional damage when they bury aquatic and terrestrial plant life.

Soil particles also carry pesticide residues and nutrients. If concentrated, pesticides can kill aquatic organisms and/or accumulate in aquatic food chains. (See index for more information on biomagnification.) Extra nutrients in soil particles can cause excessive aquatic plant growth which can lead to oxygen depletion or eutrophication. (See index for more information on eutrophication.) The decomposition of organic soil particles also uses up the dissolved oxygen needed by fish. Stream borne soil can also effect water temperature. Sunlight heats up soil colored water faster than it heats clear water. Additionally, water-borne soil reduces the water depth that sunlight can penetrate. This reduces the production of the aquatic plants which form part of a waterway's food chain base. (675)

Even without including the cost of mitigating the problems just discussed, the non-agricultural production costs caused by erosion are considerable. A 1975 report by the Council for Agricultural Science and Technology (CAST) "estimated that soil erosion cost $83 million for dredging channels and harbors, $50 million for floodplain overwash and reservoir sedimentation, and $25 million for added water treatment costs and system maintenance in municipal and industrial water systems. The CAST report also estimated that, based on 1974 prices, it would cost some $1.2 billion to replace the plant nutrients lost through soil erosion that year." (676)

Beyond these expenses, soil erosion causes other significant maintenance costs. Soil erosion deposits must be periodically cleaned out of roadside ditches, gutters, and culverts. Roads, railroad tracks, fences, and even buildings can be buried by wind blown soil. Airborne dust can also aggravate respiratory ailments. (677)

 

 

 

 

 

 
The Development Of Agricultural Soils
 

 

 

 

 

 

 

 

Development is also taking its toll on agricultural soils. Urban fringe areas in the U.S. are home to some of that nation's most productive soils. These same soils also suffer from the fastest farmland-to-development conversion rates in the United States. (678) Currently in the U.S., a million or more acres of agricultural soil are converted to tract houses, shopping malls, and roads each year. (679) Put another way, "every 15 seconds another 45 people arrive on the planet; during the same 15 seconds, the planet's stock of arable land declines by one hectare (2.48 acres)." (680)

Though population is a factor in development of agricultural soils, it is only one cause. A study titled "A Strategic Plan for Land Resources Management", released by the Northeastern Illinois Planning Commission, illustrates this point quite clearly. According to the study, "between 1970 and 1990 the greater Chicagoland area's population increased by only 4 percent, while land in residential use increased by 46 percent. The region's non-farm commercial and industrial land expanded by a whopping 74 percent" and most of this expansion was suburban. (681)

 

 

 

 

 

 
Dependence On Non-renewable Energy Resources
 

 

 

 

 

 

 

 

Another agricultural security problem is conventional agriculture's dependence on fossil fuels. The energy inputs used by farmers up until early in the 20th Century consisted of their own labor and the labor of animals. This energy was renewable, since it was supplied by the renewable food energy that farmers and their animals consumed. But starting around 1910, non-renewable fossil fuel energy began to be used in food production in the industrialized world.

Since 1910 the amount of non-renewable energy consumed in agriculture has grown steadily. In the contemporary U.S. food system, 8 to 20 units of fossil fuel are consumed for every unit of food energy that ends up on someone's table. (682) Almost half of this energy, close to 4 percent of all the energy used in the U.S. annually, is expended in food packaging. (683)

Energy consumed in the production of meat is even higher. Ten to 88 units of non-renewable energy are consumed for every unit of animal protein produced. (684) In total, the U.S. food system consumes approximately the same amount of energy contained in 320 gallons of gasoline to feed one person for a year. (685) Three hundred and twenty gallons of gasoline can propel a car averaging 32 MPG over 10,000 miles. (686)

About 4% (3.3 quads) of our national energy budget is consumed on the farm to grow food "while 10 to 13 percent (8.2 to 10.7 quads) is needed to put it on our plates." (687) In all, U.S. "agriculture uses more petroleum products than any other industry in the nation. (688)

With the passage of time, our dependence on fossil fuels to produce food has increased as our agricultural system has become less efficient. "Between 1950 and 1970 off farm energy use (excluding home cooking and refrigeration) increased by 85%, while total food consumption ... rose less than 40 percent." (689) An agricultural system dependent on non-renewable energy resources is clearly not sustainable.

Just the use of fossil fuels cuts into agricultural productivity. "A U.S. Environmental Protection Agency (EPA) study estimates that ground-level ozone spawned by fossil-fuel burning is reducing the U.S. corn, wheat, soybean and peanut harvests by at least 5 percent." (690) Walter Heck, the U.S. Department of Agriculture representative on the EPA study panel, estimates that cutting ground-level ozone by half would cut (yearly) crop losses by up to $5 billion." (691) In addition to ground level ozone, acid deposition, particularly as rain, fog, and dry particulates, also causes crop damage.

Data generated by the World Watch Institute projects that, if present practices continue, there will be a 19 percent loss in the amount of cropland globally between 1984 and the year 2000. Their study also indicates that if the current rate of soil erosion continues, the per capita amount of topsoil on our planet will decline by 32 percent during that same period. (692)

Figures for the U.S. show a similar pattern. In addition to losing around 1 million acres of farmland to development each year, (693) the erosion of U.S. topsoil "exceeds tolerable levels on some 44 percent of the (U.S.) cropland." (694)

 

 

 

 

 

 
Maintaining Genetic Diversity Of Crop Plants
 

 

 

 

 

 

 

 

Another aspect of eco-nomically sustainable agriculture is the importance of preserving the gene pool of crop plants. Until recently, the genetic characteristics of plant seeds of the same species grown in different parts of the world varied considerably. If a pest or disease develops in one strain, other strains were likely to be less susceptible or not susceptible at all to the particular pest or disease. The advent of high yield grains has been a blow to plant diversity. "In India, which once had 30,000 varieties of rice, more than 75 percent of total production comes from fewer than ten varieties." (695) Wheat cultivation in the United States is in much the same situation. (696) Cultivating vast acres of a single crop variety makes a region's or country's food supply vulnerable to the development of a rapidly reproducing disease or pest that could potentially wipe out most of a year's crop. "The decreasing genetic diversity of many major U.S. crops and livestock species ... increases the potential for sudden widespread economic losses from disease." (697)

Strategies for Creating An Eco-nomically Sustainable
Agricultural System

There are many ways to reduce soil erosion related to agricultural practices. (See Index for other entries.)

 

 

 

 

 

 
Organic Agriculture
 

 

 

 

 

 

 

 

In addition to protecting soils from erosion and development, food security is dependent on adopting ecologically sustainable agricultural practices. In other words, we must adopt agricultural systems that increase soil fertility, are non-polluting or health threatening, and that are not dependent non-renewable energy resources. Fortunately, organic agricultural, regenerative agriculture, low input/sustainable agriculture (LISA), and integrated pest management (IPM) agriculture have developed some of the potential to meet these requirements.

From the perspective of ecological sustainability, organic and regenerative agriculture are more desirable methods of growing food than LISA and IPM. Organic and regenerative agriculture expressly exclude the use of petrochemical pesticides and manufactured fertilizers. IPM and LISA take advantage of organic farming strategies but may also use inputs of chemical fertilizers and pesticides. But unlike standard petrochemical strategies, IPM does not use scheduled applications of pesticides. Instead it uses pesticides only if a problem actually exists and treats only the area being attacked by pests. (698) IPM also tries to use the least toxic pesticide available to get the job done. While IPM methods introduce some pollutants into the environment, they are less polluting than more petrochemically-oriented methods of farming. (699) Nevertheless, when these inputs are used, sustainability is reduced. Because of this liability, organic and regenerative agriculture will be the focus of the following discussion. Since the aims of organic and regenerative agriculture are very close, the term organic agriculture will be used to encompass the meaning of both terms.

As currently practiced, even organic agriculture is not eco-nomically sustainable. Organic agriculture will not be completely sustainable until the machinery and materials used in cultivating, transporting, and processing food are manufactured and delivered in ways that are eco-nomically sustainable. And to be sustainable, our whole food production system will have to be powered by renewable energy resources. (See the sections on true-cost-pricing and the potential of renewable energy resources for more details.)

Organic agriculture is a food producing system that avoids the use of toxic pesticides and manufactured fertilizers. Instead it uses biological controls for pests, and plant and animal wastes for fertilizer. Although it was largely supplanted in recent years, various forms of organic agricultural have been practiced for some 10,000 years. (700)

If our aim is eco-nomic sustainability, organic farming methods are obviously the best way to grow food. Detractors, however, argue that this would be impractical since an across the board shift to organic farming methods would result in substantially lower crop yields and ultimately food shortages.

Contrary to this widespread notion, organic farming has in many instances proven to be just as productive and sometimes more so than petrochemical methods. (701) The Spray Brother's certified organic farm in Knox County, Ohio is a case in point. Rex and Glen Spray have been farming a little over 700 acres of land organically for fifteen years. In addition to having higher crop yields per acre than their county's average, their cost of production per acre is less. (702) Excluding land charges, the cost incurred by the Spray brothers to put in a crop of corn or soybeans is 20 to 30 percent less than the Ohio state average. (703) Simultaneously, Spray Brother Farm per acre corn yields "exceed the county averages by 32 percent, soybeans by 40 percent, wheat by 5 percent, and oats by 22 percent." (704)

The Carl Lee farm in Cairo, Georgia is another example. Though his farm is not totally organic Lee uses no herbicides or pesticides. In 1981 Lee "won the national Class A dry-farm corn yield title sponsored by the National Corn Growers Association." (705) The following year, he had the third highest dry-land corn yield nationally and was number one in his state. (706)

In addition to being competitive to petrochemical agriculture in yield, organic farming has also proven to be a profitable way for farmers to grow food as well. Even though organic farming tends to require more labor, this extra expense is usually less than the cost of chemical inputs organic farmers avoid. (707)

Organic agriculture also tends to do better economically when conditions like weather are less than ideal. When rainfall is low, soils rich in organic materials are good at absorbing and storing whatever water is available. (708) If chemical fertilizers are used in lieu of adding organic material to soils, the absorption and storage of water in the soil is limited. If rainfall is excessive the tunneling of soil organisms help to keep plants from dying from a lack of oxygen in their root zones.

Adding organic materials to the soil and growing cover crops also protects against soil erosion whether from wind or water. (709) These advantages keep the yields and thus profits from organic agriculture high, even when weather conditions are less than favorable.

In short, farmers using organic, low-input, and regenerative methods "report that their costs of production are lower than those of their conventional-method neighbors. Some farmers report somewhat lower yields than their neighbors, but the yield sacrifice is frequently more than offset by cost reductions." (710)

An analysis of earlier studies appears to substantiate this observation. During periods when weather and other conditions are favorable, "yields on conventionally managed fields were generally higher than those on the organic farms". (711) When farming conditions were less favorable, "yields from organic fields came closer to or even exceeded those of the conventional fields." (712) The reduced production costs enjoyed by organic farmers are graphically illustrated by comparing the fossil fuel inputs required for organic farming versus conventional farming. Over the 5-year period, 1974 through 1978, "organic farms required about two-fifths as much fossil energy to produce one dollar's worth of crop" as conventional methods. (713)

 

 

 

 

 

 
Agricultural Eco-nomics
 

 

 

 

 

 

 

 

Organic farming's economic edge over petrochemical methods is actually larger than the figures just stated indicate. If all the eco-nomic costs, like the cleanup of pesticide and chemical fertilizers from groundwater and treating pesticide related health problems, were included in the price of petrochemically grown crops, the economic edge of organic over petrochemical would be even more striking. In a 1979 article, David Pimentel estimated that the environmental and social costs of just using pesticides totaled $840 million per year in the United States. (714) If other costs associated with conventional agriculture, like soil lost to erosion and the pollution of surface and groundwater with chemical fertilizers, were included in the accounting, organic agriculture's economic edge will be even greater. (See index for more entries.)

Added to the absence of true-cost-pricing in agriculture are the numerous government subsidies that tend to keep farmers on the petrochemical treadmill. Currently, "many federal policies discourage adoption of alternative (agricultural) practices and systems by economically penalizing those who adopt rotations, apply certain soil conservation systems, or attempt to reduce pesticide applications." (715) If these subsidies were removed, the adoption of organic agriculture would be accelerated.

Even though organic agriculture is competing against such subsidies and the lack of true-cost-pricing, organic agriculture is still holding its own in yield and profitability. This fact is even more remarkable considering that almost all the funding for agricultural research conducted over the last 50 years has been directed at improving the yields of petrochemically-supported agriculture. (716)

In recent years, agricultural colleges have made modest shifts in the direction of increasing the effectiveness of organic farming methods. But it wasn't until 1987 that "the world's first Sustainable Agricultural chair" was "established at the University of Minnesota." (717)

In spite of the myth of petrochemical agriculture's superiority, the last 25 years has seen organic farming practitioners grow in number and improve their methods. To a great extent, this growth has been driven by the public's increasing concern over the environmental and health consequences of using toxic pesticides and other petrochemicals on the food they eat. This concern, in turn, has led to a growing demand for organic produce. Up through 1987 the organic market "was expanding at a rate four times faster than that of conventional produce," and this rate of growth appears to be continuing if not increasing. (718)

"In 1987 two separate studies estimated that 40 to 50 million dollars worth of organically grown produce was sold in California alone." (719) A 1988 article in The Progressive stated that "Organic food, once relegated to health-food stores and campus areas, has become a $3-billion-a-year-and growing mainstream market as consumer concerns about pesticides increases." (720) In recent years, the adoption of organic agricultural methods has continued to accelerate. One illustration of this continued growth is the fact that, most of the wine grapes grown in California are now grown organically. And these grapes are grown organically because it works and it is a cheaper way to grow grapes.

With increased demand for organically grown food, concern has also grown related to how "organic" a product is, if it carries an organic lable. "Oregon passed the first organic labeling law in 1973. Since then 13 other states have passed similar laws, and another dozen states have such laws pending." These laws specify the growing and handling requirements for food sold in their states that is labeled "Organically Grown". (721) In some states it also requires membership in statewide certification organization which do periodic soil and plant tissue testing to insure that any food labeled grown organically is actually grown organically.

 

 

 

 

 

 
Organic Agriculture In The Future
 

 

 

 

 

 

 

 

Compared with the research dollars that have been devoted to improving the yields of petrochemical agriculture, formal research in organic methods has been almost non-existent. It therefore follows that as research in organic agriculture expands, crop yields on organic farms will undoubtedly increase beyond present levels. Indeed, continued research in this direction holds the promise of ushering in a new era of even higher yielding organic agricultural systems that will be more productive than any past or present method of agricultural production.

As in other areas, the computer will play an important role in the design and maintenance of new food production strategies. With the computer's capacity to evaluate and organize large bodies of information comes the potential to develop symbiotic multi-species agricultural associations designed to mimic the productivity and stability of naturally occurring ecologies.

Presently, most crops, even when grown organically, are grown as monocultures, one crop grown over a large area. Monocultures provide the ideal habitat for the pest that eats a particular crop and eliminates the habitat for predators that would feed on that pest. (722)

Integrated multi-species agriculture would differ from monocultures in that they would be designed to maximize the habitats of pest predators while minimizing pest habitats. Breeding and nesting places for insect eating birds, lizards, frogs, and bats would be designed into agricultural arrangements. Tall trees would anchor windbreaks and provide nesting and roosting places for hawks and owls to control rodents.

Plants, in such systems, would also be arranged to maximize the availability of sunlight. Large trees would be spaced far enough apart so that smaller trees, bushes, and annual plants could be grown among them and still receive sufficient sunlight to prosper. Shade loving plants would be grown under the canopies of appropriate plants. Deciduous (plants that lose their leaves in winter) trees and smaller plants would be interspersed with evergreens to minimize evergreens shading each other when the winter sun was low in the sky. With this arrangement, sunlight that passed through the leafless canopies of deciduous trees and smaller plants would maximize evergreen plant growth in the winter.

The integration of trees, bushes, vines, and annuals would create a multi-story or three dimensional agricultural system. In such a system, food and other products would be produced at various levels, starting at ground level with a mix of annual plants and small perennials and ending in the tops of tall trees, depending on the plants involved. Intermediate level crop production would take place in smaller trees, bushes, or vines. Multi-level productivity would increase overall yields when compared to monocultures. The productivity of monocultures, which feature a single crop growing to a uniform height, tends to be two dimensional with all the crop maturing at, more or less, the same time. In a multi-level system, the crops of different plants would be maturing at various times throughout the growing season. In mild climate areas, one crop or another would be maturing year round.

A less sophisticated form of this kind of agriculture is already beginning to emerge. "In many tropical and subtropical regions, agroforestry (the incorporation of trees and field crops into a single farming system) is proving to be highly productive. Trees can provide food, forage, fuel, organic matter in the form of leaf drop, and, if they are nitrogen fixing, nitrogen for the crops grown in the immediate vicinity." (723)

Though integrated multi-dimensional agricultural systems would tend to keep the populations of crop damaging pests low, other control agents would undoubtedly have to be used from time to time. But just as conventional agriculture draws on a variety of toxic chemical weapons in the attempt to control pests, there are an increasing number of non-toxic pest specific remedies available if the need arises. Just as poisons can be sprayed at ground level or from helicopters and airplanes, predatory insects, biocides, and other non-toxic control ingredients can be distributed in similar ways.

 

 

 

 

 

 
Organic Agriculture: Current Technologies
 

 

 

 

 

 

 

 

In recent years the science of controlling pests without using toxic agents or using them only sparingly has expanded rapidly. To explore to any depth the growing literature on this subject would require a book, if not volumes, devoted to this topic alone. What is offered here is only a snapshot of the many bio-control strategies and products that are now commercially available and some of the ongoing research being conducted in this area.

The first line of defense in controlling pests organically is the maintenance of healthy soils. Healthy soil fosters the growth of healthy plants. Like us, healthy plants are resistant to diseases and to attack by pests. With organic agriculture, soil health is maintained by using methods of cultivation which minimize the loss of soil and nutrients. These methods include mulching, covercrops, alternative tillage methods, and windbreaks. (See index for additional entries.)

Additional pest control is achieved through the use of crop rotation strategies which make it harder for pests to feed and breed. (724) Growing the same crop in the same location year after year provides a continuous supply of food for the pest population that attacks that crop. Crop rotation breaks the cycle by periodically replacing a crop that pests like, with one which will not support the pest's life cycle.

Pests can also be controlled by providing habitat for their natural enemies. Such habitats can be integrated with wildlife areas and windbreaks that provide breeding and nesting areas for pest consuming birds, frogs, lizards, and snakes. While various species of frogs, toads, birds, and lizards consume insects, snakes, weasels, hawks, and owls focus on rodents. There are also many insects that eat pests directly or kill pests by laying eggs on them or in them. When these eggs hatch into larva, they grow to maturity by eating their host.

If provided with the appropriate habitat, these organisms are very helpful in controlling pests. For example, China has been inter-planting cotton with other crops to attract cotton pest predators. Although, pesticides are still used in this system, their application has been reduced to one-fifth of what would have normally been used and the income earned by the interplanted fields averaged 22 percent more than from cotton fields grown without interplanting. (725)

Though research in the area has been scant, the success record of biological control measures is impressive. "According to Dr. Ken Hagan of the University of California Berkeley's Division of Biological Control, introduction of natural enemies has brought 60 major pests under complete biological control, another 60 under substantial control, and 40 under partial control." (726) By comparison, "crop losses from insect damage have increased from 7% in the 1940's to 13% at present despite a ten-fold increase in insecticide use." (727)

In addition to being homegrown, a number of factory grown predatory insects and parasites can be purchased and applied like pesticides. By 1989 the public demand for pesticide free food had spawned an estimated $25 million industry worldwide to supply beneficial pest fighting organisms. Actually the amount of money involved in the use of beneficial organisms is much higher than $25 million. China and the former Soviet Union produce large numbers of beneficial organisms. But the capital resource involved in their programs is not public information and is not included in the $25 million estimate. (728) Since 1989, the beneficial organism industry has continued to grow, to keep pace with the switch to non-toxic pest control methods.

Use and improvement of the many strategies and controls discussed here will usher in an agriculture of the future that will work in harmony with nature on every level. And, like nature, it will be extremely productive. As in other economic sectors, the implementation of true-cost-pricing is an important aspect of accelerating the development of sustainable agricultural systems and their adoption around the globe.

 

 

 

 

 

 
Agricultural Appendix
 

 

 

 

 

 

 

 

This section is for those who would like a more in depth look at some of the organic methods currently being used in agriculture and a few of the new tools being developed. It will also take a more detailed look at the numerous problems presented by our current petrochemically based agricultural system.

Biocides are just one class of organisms currently produced by the beneficial organism industry for use in agriculture. Biocides are naturally occurring bacteria, fungal, and viral agents that attack various agricultural pests and diseases. "Organisms used for biocontrol of soilborne pathogens are generally either soil bacteria or fungi." (729) "Bacteria such as B. subtilis are popular for seed treatment because they form spores that are stable and easy to apply." (730) The effectiveness of B. subtilis in controlling soilborne pathogens is reflected in increased yield. "After treatment yields of carrots have increased by 48%, oats by 33%, and peanuts by 37%." (731) Bacillus thuringiensis or BT is mixed with water and sprayed on plant foliage. As insect larvae eat foliage, they ingest BT which causes them to sicken and die. BT kills tomato hornworms, cabbage worms, and other butterfly family larvae.

Bacillus Popilus, another commercially available organism, is fatal to the grub larvae of the Japanese beetle, another crop damaging insect. (732) The biocide B. bassiana, a fungal pathogen, is used to control "sweetpotato" whiteflies. This pathogen attacks the sweetpotato whitefly at every stage of its life cycle "from egg to adult on cotton, vegetables, and ornamentals." (733)

Sometimes biocides work in concert. "Entomophora grylli (a complex of more than one species) is being used to control grasshoppers." (734) Biocides can even be used to protect agricultural products from decay after they have been harvested. To reduce spoilage, "antagonistic" bacteria, yeasts, and fungi "compete with pathogens for nutrients, or attack them directly with secretions of antibiotics, enzymes, and other substances." (735) From 12 to 23 percent of fresh fruit and vegetables are lost to spoilage after harvest. Losses are as high as 50 percent without refrigeration or other measures. (736)

Still in the research stage is the celery looper virus. This virus, which is naturally occurring, could be commercially available in the next five years. While the use of biocides to control pests is becoming increasingly common "the celery looper virus stands out from others because of an impressively broad array of destructive insects it kills." (737) Pests susceptible to the virus include: the pale-green celery looper, the cabbage looper, the tomato and tobacco hornworm, the cotton bollworm (a.k.a. corn earworn and tomato fruitworm), the pink bollworm, the tobacco budworm, and a number of other wormlike pests. (738)

Nematodes, small wormlike organisms which live in the soil, can also be used to control pests. Insect-attacking nematodes have been used in the U.S. to control pests on "citrus, cranberries, turf, figs, hops, mint, strawberries, sweet potatoes, and rhododendrons." (739) "Nematodes are also being used successfully against fly larvae in poultry and dairy operations." (740) The first commercially available insect-attacking nematodes developed in the U.S. were used to control mosquitoes in the 1970s. Current research is exploring the use of beneficial nematodes to control wireworms, cutworms, cabbage root maggots, onion maggots, white fringe beetles, cornworms, black vine weevils, flea beetles, and the sweet potato weevil. (741)

Pheromones, which are powerful hormones emitted by insects to attract mates, are another tool available to organic farmers to thwart pests. Pheromones can be used to reduce pests by confusing them during breeding periods, so they are less successful at breeding, or to lure them into traps. (742)

Recent research in pheromone use has focused on controlling nematodes. While many nematodes are beneficial, some of the transparent eel-shaped worms damage plant roots while they drain nutrients from them. "Scientists estimated that the soybean Cyst nematode, Hererodera glycine, costs (soybean) growers $420 million a year in crop losses." (743) Historically, nematodes have been controlled by applying nemacides to the soil. This is costly and groundwater contamination is a concern. Now, scientists are testing pheromones as a nematode control agent. In the quest for a pheromone solution, pheromones were first isolated from female nematodes by Robin L. Huettel and then approximated (close enough to the real thing to fool the target pest) by chemist Albert B. DeMilo. At the beginning of their life-cycle, hatching young nematodes attach themselves to soybean roots with "a needlelike mouthpart called a stylet". "When a male nematode matures, he leaves the root to seek a mate, drawn by the female's pheromone." The strength of the pheromone signal tells the male nematode when a female is near, which triggers "a dance like rite--coiling and uncoiling--in an effort to mate." When the pheromone substitute is applied to the soil, the chemical "noise" confuses the male nematode so that he can't find a mate. To the degree that this happens, less nematode eggs are fertilized. (744)

Beyond the growing arsenal of beneficial organisms, several other pest control measures are available to organic farmers. Oils, for example, have been used to control pests for thousands of years. Various petroleum derived oils are advertised with names like "dormant," "summer," "superior," "supreme oil," and other designations. While these oils are more or less non-toxic and effective as pest control agents they are still made from a non-renewable resource.

Renewable plant oils are also being used to control pests and "rank with petroleum oils in killing aphids, whiteflies and spider mites on cotton and vegetable plants." (745) A common way to apply oils is to mix them with a detergent in water and spray them on plants. To keep the oil/detergent blend uniformly distributed in the water medium, it is necessary to keep the spray container constantly agitated. (746)

Insecticidal soaps are also used to control pests by them selves. In experiments to test the effectiveness of insecticidal soaps, "mite reproduction rates were reduced by 8-fold" compared with controls. (747) Additionally, "there was 100% mite mortality with oleic acid and a 75% mortality from cis-linoleic acid." These are ingredients in the Safer brand insecticidal soap. "After one fatty acid treatment, plants showed none of the yellow pin-prick symptoms of mite feeding even after 30 days of monitoring." (748)

Mixing insecticidal soap with oil has also proven to be effective against pests on which soap alone had little effect. In studies on controlling the pear rust mite in Michigan it was found that Safer soap had no measurable effect. But "a concentrated spray of 2% Safer soap plus 2% Ultrafine oil was as good as (the toxic chemical controls) avermectin, kelthane, dithane and Mitac@." (749)

As discussed earlier, maintaining the genetic diversity of crop plants is very important. Insects that attack plants are constantly mutating. Greenbugs, aphids "that injects a toxin into seedlings as they feed," are especially adept at hybridizing or forming new races or biotypes if "suppressed by pesticides or host plant resistance." (750)

In an average year, greenbugs will "inflict a $67 million loss on U.S. wheat farmers". In a bad year, the state of Oklahoma alone can sustain damage in the $150 million range. (751)

To counter this damage, plant geneticist David Porter is working on cutting into greenbug related wheat losses by using 5 breeding lines of wheat, developed by the geneticist Emil Sebesta. These lines are resistant to "the three most prevalent and destructive biotypes of greenbug -- B, C, and E, plus a new and particularly destructive biotype, G." Porter is now involved in "crossing several breeding lines to combine the desired resistance genes. (752)

Genetic breeding also promises to be a valuable tool in protecting crops against rust-causing fungi. Rust is one of the most damaging diseases of the bean plant. According to plant pathologist Rennei Stavely, "in a bad year, it (rust) can cost $250 million in (beans) losses nationwide." (753) Through his work Stavely discovered that "nature gave a few P. vulgaris plants -- and related species -- the genetic know-how for stopping rust from taking hold, or bowing so slightly to it that there's little or no loss in bean yield or quality." (754) "Stavely and colleagues are putting those genes into breeding lines that commercial breeders are turning into market varieties. Since 1984, the scientists have released 53 lines of beans resistant to all 55 rust races. (755) " Porter's and Stavely's work, and that of plant geneticists in general, highlights the need to protect the genetic diversity of plants. If we let gene pools shrink, the possibility of breeding pest resistance into plants will be greatly hampered.

Although rust-causing fungi and other fungal species can cause crop damage, scientists are using some species of fungi to protect crops. A mutated strain of the fungus, Verticillium lecanii is being used to prevent the eggs of soybean cyst nematodes from hatching. In one test, "nematode populations were 70 percent less on soybean plots protected by the fungus than on plots where nematicide was mixed into the soil." When fungus was used in conjunction with pheromone compounds, the reductions were 86 percent. (756) As attractants, pheromones can be used to attract organisms into traps or broadcasted into the general environment to confuse pests seeking to mate.

Fungi are also being used against each other. When peanuts are infected by the fungi Aspergillus parasiticus and A. flavus, "they can produce a natural toxin known as aflatoxin which means financial losses to peanut growers." (757) If aflatoxin is found in peanuts in concentrations of more than 20 parts per billion, the U.S. Food and Drug Administration prohibits their use for human or animal feed in most instances. Twenty parts per billion is less than 20 drops in 10,000 gallons of liquid. According to the Peanut Advisory Board, aflatoxin contamination cost U.S. "peanut growers an estimated $25 million annually." Through ongoing work begun in 1980, scientists have isolated a parent fungi strain and developed a mutant fungi that are "very effective in controlling aflatoxin in peanuts." Not only are both the parent strain and mutant "highly competitive in the soil" at displacing the toxin producing fungi, they do it without increasing the soil's overall fungal population. (758)

 

 

 

 

 

 
Petrochemical Agriculture:
Why It Is Not Eco-nomically Sustainable

 

 

 

 

 

 

 

 

With the advent of petrochemical farming in the 1930's, organic farming was largely supplanted in the industrialized world. This resulted from the fact that petrochemical imputes like pesticides and chemical fertilizers had the effect of increasing crop yields dramatically over the average crop yields of the period. Although, as the material previously discussed has shown, scientifically applied organic farming methods in use today can meet or even exceed the yields and profits of petrochemical practices.

One of the most important ingredients in the petrochemical regimen is pesticides. When pesticides were first introduced, they were hailed as scientific miracles. Pesticides were the magic wand that promised to end the age old struggle between humanity and the myriad of pests which prey on us and our crops. Unfortunately, this promise was not to be fulfilled.

One reason for this failure is that pesticide use triggers a process that results in the selection of pest populations that are pesticide-resistant. (759) When pesticides are used, they kill the members of a particular pest population that are most susceptible to them. This leaves a residual population of pesticide-resistant pests, which reproduce and pass on their resistant genes to their offspring.

Pesticide resistance was documented as early as 1914 when it was discovered that San Jose scale was resistant to lime sulfur sprays. (760) Since that early discovery, the number of resistant pests have grown. To date, according to the National Resource Council, "more than 440 insect and mite species and more than 70 fungus species are now known to be resistant to some pesticide." (761)

With increasing pesticide use this selection process seems to be accelerating. Between 1970 and 1980, "the number of insects resistant to insecticides nearly doubled." (762) Some pests have even developed resistance to multiple pesticides. As of 1983, "at least 25 species (of pests) can resist the four principal classes of insecticides: DDT, cyclodienes, phosphates, and Carbamates." (763) As many as "10 insects have already developed resistance to a new class of insecticides, the synthetic pyrethroids." (764)

In all, the amount of crop damage caused by pests since pesticides were first introduced has doubled, even though the amount of pesticides used nationally and their toxicity level has increased many-fold. (765) "In the 1940's when little insecticide was applied to corn, 3.5 percent of the crop was lost to pests. Though insecticide use has since gone up 1,000 fold, losses (are) up to 12 percent." (766)

By 1975 the annual pesticide use in the United States had risen to "an estimated 1.1 billion pounds of pesticides, or about 5 pounds per person". (767) Of this 1.1 billion pounds, "about 700 million lbs. of pesticides--of which about 38% are insecticides, 52% herbicides, and 10% fungicides-are applied to crops and farm lands." (768) By 1988 pesticide use in the U.S. had risen to around 2.6 billion pounds, almost 2.4 times the 1.1 billion pounds used just 13 years earlier. (769)

Pesticides amplify the problem of pest damage further by harming animals, like birds and insects, that eat pests. Since the life-cycle of predator organisms is often longer than the pest they eat, it takes longer for them to develop a pesticide resistant population. This means that as pests develop resistance to pesticides there are less natural predators to take up the slack. With natural predator populations down, there is a resurgence of resistant pests, which triggers still more pesticide application -- these further debilitating predator populations just when they are recovering from the initial pesticide application. (770)

This "'pesticide treadmill'" is further aggravated because pest predators, like birds, may pick up a debilitating or even lethal dose of pesticides by eating a quantity of pests that are pesticide contaminated, even though the pesticide does not affect the resistant target pest.

The use of pesticides, especially broad spectrum pesticides has also been associated with the "creation of secondary pests." (771) Secondary pests are created when the natural enemy of a non-problem pest is debilitated by pesticides being used to control a target pest. Even though the pesticide application may control the target pest, it may unleash another pest whose population growth had previously been held in check by natural predators.

There are numerous examples of this phenomenon. Mites, for example, "have only become important pests since the introduction of broad-spectrum insecticides." Another example occurred in Peru. When insecticides were used to control pests attacking Peruvian cotton in 1949 the initial result was "a dramatic increase" in yield. But with the passage of time, the pesticide induced ecological disruption led to an increase in the number of cotton pests from 6 to 16. "This eventually resulted in the lowest yields ever during the 1955-56 season, and necessitated the development of a new approach to pest control." (772)

In 1970, 25 species of insects in California caused at least one million dollars worth of damage to agriculture. "Of these 25 insects, 17 species were resistant to one or more pesticides, and 24 of the pests were the result of secondary pest outbreaks or resurgences." (773)

The use of pesticides also kills other beneficial organisms like the honey bee. "Honey bees and wild bees are vital to the production of about $20 billion worth of fruit, vegetables, and forage crops." (774) It has been estimated that "the loss of honey, and reduced crop yields" resulting from pesticide-caused honey bee deaths "accounts for at least $135 million in losses (in the U.S. each year (Pimentel et al. 1980). (775)

 

 

 

 

 

 
The Effect Of Pesticides On People
 

 

 

 

 

 

 

 

As early as 1974 the U.S. EPA estimated that up to "'14,000 people may have been nonfatally poisoned by pesticides in a given year, 6,000 seriously enough to require hospitalization". (776) Annually, there are about 200 deaths from pesticide exposure in the United States. (777)

Although a large percentage of the poisonings cited above were of people working in agriculture, consumers of food grown with pesticides are also at risk. "In the summer of 1985, nearly 1,000 people in several western states and Canada were poisoned by residues of the pesticide Temik in watermelons. Within two to twelve hours after eating the contaminated watermelons, people experienced nausea, vomiting, blurred vision, muscle weakness, and other symptoms." (778) Although no person died, symptoms "included grand mal seizures, cardiac irregularities, a number of hospitalizations, and at least two stillbirths following maternal illness." (779)

A 1987 report by the National Academy of Sciences "concluded that pesticides in our food may cause more than 1 million additional cases of cancer in the United States over our lifetimes." (780) An analysis by the Natural Resources Defence Council of fruits and vegetables from San Francisco supermarkets "found that 44% of the produce contained measurable residues of pesticides; 42% of the samples with residues contained more than one chemical," and "some had as many as 4 different pesticides present." (781)

An EPA report, entitled Unfinished Business, published in the same year, "ranked pesticides in food as one of the nation's most serious health and environmental problems." (782) As of 1988 the EPA had "identified fifty-five pesticides that could leave residues in food as being carcinogens." (783) This number is probably conservative considering that "a 1982 congressional report estimated that between 82 percent and 85 percent of pesticides registered for use had not been adequately tested for their ability to cause cancer; the figure was 60 percent to 70 percent for birth defects, and 90 percent to 93 percent for genetic mutations." (784) "In 1987 Consumers Union surveyed 50 common pesticide ingredients and found that only one had been properly tested for neurotoxicity." (785)

 

 

 

 

 

 
Herbicides: Deja Vu All Over Again
 

 

 

 

 

 

 

 

Though weed killing pesticides or herbicides are late entries in the pesticide arsenal they have been found to carry liabilities similar to those that emerged with the use of other pesticides. Herbicides were first used commercially in the late 1940s. According to a report by the U.S. Dept. of Agriculture Economic Research Service published in 1988, herbicides were used in the cultivation of 95% percent of the soybeans and corn grown in the U.S in 1987 and in 60% of the wheat farming operations. (786)

"Herbicides now account for 50 to 60% of synthetic pesticide production at the 330 U.S. pesticide (production) plants" (30% are insecticides and miscellaneous pesticides and 20% are fungicides). (787) The principal attractiveness of herbicides is their capacity to eliminate undesirable plants with a minimum amount of labor.

Recently, concerns about the potential side effects of herbicide use have been raised in light of suggestive evidence linking herbicide use to birth defects in unborn humans and other animals. (788) Although it is only one element in the herbicide controversy, dioxin and in particular the dioxin compound known as TCDD or 2,3,7,8-tetrachlorodibenzxo-p-dioxin has drawn the most fire.

TCDD, an unavoidable byproduct of herbicide manufacture, is one of at least 75 dioxin compounds. "Little information is available about the toxicity of most of these dioxins - either separately or in combination - but it is known that TCDD is a fetus-deforming agent 100,000 times more potent than thalidomide, and that (it) is toxic at any level of exposure measurable, down to parts per trillion." (789) Thalidomide is a tranquilizer that was prescribed in the 1960s to "alleviate the psychological and physiological symptoms often accompanying early pregnancy". (790) During the three-to -four year period that the drug was prescribed, "thousands of severely deformed babies were born." (791)

Herbicides have also been implicated in the development of serious health problems in workers who are exposed to them. "A 1986 study by the National Cancer Institute found that Kansas farm workers who were exposed to herbicides for more than 20 days per year had a 6 times higher risk of developing Non-Hodgkin's lymphomas (NHL) than non-farm workers." (792)

Liabilities like those described above are even more alarming considering that the long-term use of herbicides may actually make the problem of controlling weeds more difficult than it was before herbicides were introduced. Like insects that have become resistant to pesticides, some "super weeds" are showing a similar capacity. Since this phenomenon was first cited in 1970, "at least 54 weed species, a 450% increase since 1980," have developed a resistance to herbicides. (793)

Specialists in chemical weed control have expressed confidence that they can answer this challenge by attacking weeds with a rotating barrage of herbicides from different classes. Even if this were true, the health and environmental risks are probably not worth it -- particularly considering that there are many physical and biological options available for weed control that have few if any health or environmental liabilities.

 

 

 

 

 

 
Non-toxic Weed Control
 

 

 

 

 

 

 

 

Although a safe weed control product has not yet been marketed, there are many methods for controlling weeds that do not require toxic materials. Ever since the dawn of agriculture, people have strived to overcome weeds that competed for nutrients, water, and sunlight with their crops. Many of the methods they pioneered, like pulling weeds, plowing or hoeing them under, covering them with mulch, growing aggressive cover crops to squeeze weeds out, and turning an assortment of geese, goats and other animals loose on them are still effective strategies.

Modern biological weed control made its accidental debut around 200 years ago. Aiming to break the lucrative Spanish red dye monopoly in Mexico, the British imported the Brazilian Scale insect into Northern India. But instead of importing the cochineal species associated with red dye production they mistakenly imported a Brazilian relative. Though the Brazilian species was not good for the production of dye it did attack and finally eliminate the undesirable South American weedy prickly pear which had spread unchecked throughout India after its introduction. (794)

Since the accidental introduction of the Brazilian scale into India 200 years ago, many other biological control organisms have been introduced around the world to control undesirable plants. In addition to being more ecologically benign and non-health threatening, biological control methods are also economical.

During the 1940s the Klamath beetle was introduced into a two million acre area in California to control the Klamath weed. The Klamath weed which is also known as St. John's-wort, crowds out nutritious forage plants and is poisonous to sheep and cattle. Within a decade of its introduction the Klamath beetle had eliminated 99% of the Klamath weed in the control area. The savings, over other control methods, continues to range in the millions of dollar per year. Just during the years from 1953 to 1959 the savings amounted to 20 million dollars. (795)

The U.S. Department of Agriculture's Agricultural Research Service (USDA/ARS), the agency responsible for bio-control research, estimates "that its four complete successes against weeds since 1944 (i.e., Klamath weed, alligatorweed, Alternanthera Philoxeroides, puncturevine, Tribulus terrestris, and Tansy ragwort, Senecio jacoboea) results in annual benefits of $155.6 million per year." (796)

Given that the "total ARS biocontrol research budget was only $21.5 million in 1988,", "the cost effectiveness of biological control technology (for weed control) is hard to deny (USDA/ARS 1989)." (797) If peripheral costs like the avoidance of water pollution and health problems associated with use of chemical controls are added, the savings would be considerably higher. By replacing expensive herbicides, biocontrols also reduce overhead costs by several hundred million dollars each year.

Developing plants with built-in weed control systems is a new nontoxic way to keep weeds at bay. In the mid-1980s plant geneticist Robert Dilday noticed that ducksalad, an invasive weed that plagues rice farmers, "would grow right up to some rice plants, but other rice plants didn't have any of the weed around them." (798)

This discovery led Dilday on a research quest to isolate rice varieties that had allelopathic (growth inhibiting) properties against ducksalad. In 1988 and 1989 Dilday and fellow researchers, Roy J. Smith and Palo Nastasi of the University of Arkansas "evaluated some 10,000 rice accessions (varieties)" for allelopathic properties. (799) Their work resulted in the discovery of 347 rice varieties "with allelopathic activities against ducksalad." They also "identified 132 rice varieties that repelled redstem, another aquatic weed, and six that looked promising for resistance to broadleaf signalgrass." (800)

Dilday believes the information he and his colleagues have uncovered can be used in at least two ways. One would be to breed allelopathic characteristics into commercial rice varieties. Preliminary work in this direction looks promising. He also sees the possibility identifying the chemical that the allelopathic plants produce. If these chemicals can be identified, they might be able to be produced commercially.

Another difficulty with many pesticides, herbicides included, is that they do not degrade easily. In both agricultural and landscaped settings, pesticide residues that do not break down in soil and water can be absorbed by plants or ingested by herbivore (plant eating) animals and insects.

Although biological methods for controlling all weed problems have not been developed, it is definitely an area where more research would be valuable. But even today, current biological control methods in combination with other non-toxic weed control strategies are sufficient to eliminate the use of most if not all chemical controls.

 

 

 

 

 

 
Biological Magnification
 

 

 

 

 

 

 

 

Through a process called biological magnification, many pesticides like DDT and its relatives "accumulate in the fatty tissues of organisms, especially those at the high end of the food chain." (801) When these organisms or their products (like milk and eggs) are eaten, pesticide residues further concentrate in the body of the animal or person who eats them.

In general, such concentrations increase around 10 times with each step up the food chain. One four level food chain study traced the biological magnification of DDT from plankton to silversides (a small plankton eating fish) to needlefish, to the osprey. At the osprey end of this food chain DDT was 345 times more concentrated than it had been in the original plankton. (802)

Animals like bald eagles, ospreys, bears, and humans that consume animals and animal products from the high end of the food chain are exposed to the highest concentrations of food chain pesticides. Such concentrations have been linked with a decline in the reproduction of predatory birds. (803) An Environmental Protection Agency study released in 1983 stated that 99% of all Americans have some pesticide residues in their tissue.

The contamination of breast milk is one of the more frightening aspects of food chain contamination. Pesticide-contaminated breast milk has shown up in areas as widespread as Montana, New York, Virginia, Michigan, and Hawaii.

Studies conducted over the last 30 years to detect DDT in human milk have not shown a decline even though DDT was banned in 1972. "E.J. Calabrese comments there does not seem to be a downward trend in DDT levels in human milk over the 30 years since the original reports. He notes that despite the differences between studies, all reported that breast milk had such high levels of DDT that substantial percentages of nursing infants were ingesting more DDT than was considered acceptable by the World Health Organization. Calabrese states that cow's milk containing the average level of DDT found in human milk would have been banned by the Federal Department of Agriculture." (804)

Additionally, pesticide residues carried by wind and runoff can contaminate waterways and can leach into groundwater supplies. "Pesticides have been detected in the groundwater of 26 states as a result of normal agricultural practices." (805) These contaminants include 30 herbicides and 7 insecticides. (806)

 

 

 

 

 

 
Chemical Fertilizers
 

 

 

 

 

 

 

 

Like pesticides, chemical fertilizers seemed to be an answer to the farmer's dreams. Like a magic potion, the application of chemical fertilizers increased crop yields dramatically. Initially the use of chemical fertilizers seemed to have no drawbacks but as time passed a number of problems emerged.

"Soils are the natural, living systems where the root systems of most higher plants live, along with millions of microorganisms that carry out essential functions of converting minerals, dead plant and animal remains, water, and air into compounds that nourish the plants in a continuous cycle of life." (807) While petrochemical fertilizers provide nutrients for plants, they do not provide food for soil organisms. If concentrated, petrochemical fertilizers can even be toxic to them. Soil organisms die without food. This coupled with the lack of organic material, leaves soil less able to absorb moisture which makes soils more vulnerable to wind and water erosion.

Research has also shown that nitrogen fertilizer also diminishes the uptake of methene gas by soil microbes. (808) With less uptake, more greenhouse potent methane gas is being released into the atmosphere. "Now a soil scientist has added vitamin C depletion to the list of drawbacks" associated with the use of nitrogen fertilizers. (809) Studies conducted by Sharon B. Hornick of the USDA's Agricultural Research Service showed that "too much nitrogen" from any source reduced the vitamin C content by close to 30 percent in chard. Hornick's work also showed that excessive nitrogen also reduced the vitamin C content "in green beans and kale." (810)

Although it appears that excessive nitrogen, in any form, can diminish the vitamin C content in at least some plants, this is less likely in healthy soils. In healthy soils, abundant soil organisms release the nitrogen bound up in organic materials at rates that can be more fully utilized by plants.

Petrochemical fertilizers are also more likely to cause water pollution problems than are plant residues and manure. When petrochemical fertilizers are applied, more nutrients are often available than plants can readily use. The excess is carried off by runoff or leaches into the soil beyond plant root zones and eventually into groundwater supplies where it is a harmful contaminate. When children drink contaminated well water, nitrate ions (NO3-) from artificial fertilizers are converted by intestinal bacteria in children into nitrite ions (NO2-). The reaction of NO2- with blood hemoglobin causes anemia in children which is debilitating and in extreme cases can be fatal.

In contrast, as soil organisms break down organic materials found in plant residues and manure, plant nutrients are slowly released. This slow release allows plants to absorb nutrients with a minimum of nutrient loss. Organic materials in the soil also help to hold water and keep nutrients from leaching away before plants can absorb them. In short, adding "organic matter improves soil quality by granulation, water infiltration, nutrient content, soil biota (soil organisms) activity, and soil fertility and productivity." (811)

Agriculture in the future will work in harmony with nature on every level. And, like nature, it will be extremely productive. As in other economic sectors, true-cost-pricing will accelerate the development of sustainable agricultural systems and their adoption on a global scale.

 

 

 

 

 


Jim Bell 4862 Voltaire St. San Diego, CA 92107 jimbellelsi@cox.net