By SAMUEL R. ALDRICH
Which system can meet the food needs in today's world?
Conventional v. organic farming
|ENVIRONMENTAL concerns, fear of possible pesticide residues in foods and declining energy resources have breathed new life into "organic gardening," a small movement of long standing. Proponents have claimed for many years that "organically" grown food tastes better and is more healthful. In recent years the claim has been added by some that "organically" grown crops are more resistant to insects and diseases. Finally, organic farming has been suggested as a means to reduce energy needs in food production and to avoid depletion of the ozone shield which it is postulated results from the escape of nitrous oxide into the stratosphere Following the use of nitrogen fertilizer. The ozone layer in the stratosphere filters out a substantial amount of the ultraviolet radiation from the sun. It is believed that a reduction in ozone would result in some increase in skin cancer, and there is speculation that it might adversely affect other living organisms and modify the climate.|
The terms "organic" and "natural" in relation to food cannot be precisely defined, but some meaningful generalisations can be made. "Organically grown" means that the grain, vegetable or fruit was grown without commercial fertilizers and synthetic pesticides. Some organic proponents accept the use of naturally occurring pesticides such as rotenone (from roots of the Derris plant) and pyrethrum (from the flowers of chrysanthemum species). Unprocessed phosphate rock as a source of phosphorous and greensand as a source of potassium are approved substitutes for fertilizers. The main distinction in fertility programs is the use of synthetic nitrogen fertilizers in commercial agriculture as compared to only crop residues animal and human manures and food wastes in "organic farming." "Organic" meat, milk and eggs means that the poultry and livestock were fed "organically" grown crops and that no growth hormones or antibiotics were used. The term "health" foods usually implies that no preservatives or coloring agents have been added.
There has been a strong back-to-nature movement during the past decade, especially among youth. Natural or organic food is often, though not always, part of their lifestyle. They are one or two generations removed from farming, hence have lost touch with the land and how things grow.
They find an escape from the artificiality of big city life, healthful exercise and a special sense of accomplishment and self-reliance in planting, growing and harvesting their own food. Being untrained and unskilled in the basics of of plant growth, they have an almost mystic reverence for nature and a fear of man-made chemicals. Some have developed a genuine concern for possible residues of pesticides and food additives. Their concerns are reinforced by highly selective reading and acceptance of antichemical literature to the exclusion of more scientific and better balanced reports. Others simply feel that "nature knows best."
Taste, nutrition, health
Many organic farming enthusiasts claim that organically grown food has better flavor and is more nutritious. The effects of handling and processing are likely being confounded or confused with the cultural methods used in growing and delivering the product. Some vegetables lose much flavor if stored even under refrigeration for a few days and even more in an open display counter. Fruits and fresh vegetables that are grown at great distances from the supermarket are likely to be in transit and storage for a week or more. Fruits which bruise easily and rot quickly must be picked before they are fully ripe. Though ripe when offered in the counter of the supermarket, they are not as flavorful as if permitted to ripen on the plant.
Some organic or natural food stores obtain fruits and vegetables from local growers, and their clientele are conditioned to accept foods that have blemishes. Consequently, specialty stores can more easily offer tree or vine-ripened fruits and vegetables. Persons who grow their own food enjoy the ultimate in
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freshness and flavor. When improved freshness and flavor are combined with the great personal satisfaction involved in growing one's own food, it is easy to see why there is much enthusiasm for homegrown fruits and vegetables whether organic or not.
Dr. Ruth Leverton, science adviser in the Agricultural Research Service, U.S. Department of Agriculture, says that food labeled as organic is not likely to contain more vitamins than similar foods not considered organic.
The notion that organically grown food is somehow different is based upon lack of understanding of the way that plant nutrients enter plant roots. This is clearly explained by Dr. Milton Salomon, chairman of the Department of Food and Resource Chemistry, University of Rhode Island:
"When organic matter breaks down in the soil, mineral fertilizer elements such as nitrates, phosphates, calcium, and others are released to the soil solution for subsequent uptake by plants. When chemical fertilizers are added to soils, the same elements are made soluble rather quickly and they, too, are then absorbed by plant roots. The plant does not and cannot distinguish, for example, nitrate from a compost pile from that coming from an inorganic chemical source.
Whatever you feed the plant, it eats the same thing, whether it's organic or inorganic."
The use of the term "health foods" should be discontinued. It implies special health-improving characteristics which not only are unproven but are in many cases denied by competent, unbiased authorities.
Unfortunately, preservatives and artificial coloring compounds have often been lumped together and declared hazardous chemicals by organic gardeners and by environmentalists. Color compounds do not add calories or nutritive value or prevent spoilage. Preservatives, on the other hand, serve highly useful purposes. They add greatly to the shelf life of baked goods in the store or at home by delaying mold growth. Molds are only an annoyance to some persons, but others are extremely allergic to them. Nitrite prevents the development of botulism, a deadly poison. Other preservatives delay the development of rancidity in fats and oils. Whether there is excessive use of preservatives will not be debated here, but a blanket rejection of them would have a serious effect on food supply, on the appearance and flavor of many foods and the nutritional value and safety of some.
Organic and natural foods usually cost substantially more than their counterparts in supermarkets. This results from higher costs of production because of lower yields, less efficient marketing channels and lack of economies of scale. The 1974 yearbook of agriculture shows that a market basket of 55 common food items cost $33.31 in a supermarket as compared to $55.42 in a natural food store.
This is a chemical age in the use of fertilizers to increase crop yields, pesticides to protect crops, and antibiotics and hormones to increase productive efficiency of livestock. Many persons are asking whether alternative farming systems can be devised that are not dependent, or at least less dependent, upon these materials which they perceive to be energy intensive and threatening to some sectors of the environment and to human health. This is a very complex matter which can only be discussed in part in this forum.
Organic farming as originally devised by Sir Albert Howard was designed as a farming system for impoverished and remote areas of India where farmers had little or no money with which to purchase fertilizers and no feasible way to transport them from factories to farms. Organic farming has since evolved into opposition to the use of any processed fertilizers.
Some of the current controversy over conventional versus organic farming for commercial-sized farms is based upon misunderstanding. Recent writings on organic farming which stress the importance of wise use of crop residues and of animal manures imply that agronomists and modern commercial farmers ignore animal manures and efficient use of crop residues or are somehow opposed to them. This is a serious distortion. Farmers who follow either system and have livestock generally attempt to conserve and preserve manure and return it to the land. There are exceptions, of course, in the case of very large confined livestock operations. Furthermore, legume crops, which are capable of obtaining nitrogen directly from the air through bacterial
nodules on their roots, are grown for hay and pasture on both organic and nonorganic farms. From the standpoint of fertility programs, the difference is that nonorganic farms often receive supplemental nitrogen whereas organic farms do not.
It may legitimately be asked whether conventional farms which have substantial acreages of legumes and moderate amounts of manure tend to purchase and apply more nitrogen than is economical? If the answer to that question is yes, then the proper course is to provide convincing and persuasive information to farmers so they will supply an adequate but not excessive amount of nitrogen, rather than to conclude that they should shift to organic farming.
By far the most important question about organic farming is how yield s compare with conventional farming. A survey begun in 1974 by Washington University, St. Louis, Mo., comparing organic and nonorganic farms in five Cornbelt states is the basis for several recent news stories indicating that organic farms are nearly competitive. There are major deficiencies in this study which preclude using it as a valid basis for assessing the two systems:
• The number of farms is small, 16 in 1974 and 14 in 1975.
• Yields were not measured. Farmers were asked to recall their yields from the previous year.
• Different crops were grown. All farms grew corn, most grew soybeans and nearly half grew hay. Crops grown to different extent included oats, wheat, milo, rye, barley and buckwheat.
• The two farming systems had different total numbers of livestock units and different proportions of beef cattle, dairy cattle, swine and poultry.
• There is no information on the managerial capabilities of the farmers in the two systems.
• The total acreage per farm was similar but the conventional farms averaged 348 acres of cropland compared to 250 for organic farms. The sponsors of the study indicated that soils were comparable. The loss of 98 acres of cropland on organic farms is crucial to the comparison. Much of it was in permanent pasture, which is much lower in food producing capacity than is cropland. The study team reported the income per acre of cropland!
• Because of the preceeding points a
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whole-farm system is simply not a suitable research entity. It is impossible to identify the cause or causes of observed differences.
The reported value of crops on organic farms averaged 8 per cent less per acre of cropland in 1974 arid about 12 per cent less in 1975 than on conventional farms. As a result of having less acres of cropland and more pasture, the deficit would be substantially greater on a whole-farm basis.
The study team reported that organic farms required less than one-half as much energy per dollar of crop produced. Most of the difference was in nitrogen fertilizer. University of Illinois researchers calculated that each unit of energy to manufacture and apply nitrogen fertilizer properly used for corn returned more than five units of energy in additional grain. In short, nitrogen fertilizer results in a gain rather than loss in energy. When the higher costs of production on conventional farms were subtracted from gross returns, net incomes per acre of cropland in the two systems were about equal. It should be kept in mind, however, that there were 98 fewer acres and 10 per cent less output per acre for the two years.
The best available information to compare the crop production in organic and conventional farming systems in Illinois is data from the 101-year-old Morrow Plots on the campus of the University of Illinois at Urbana-Champaign. These plots were established in 1876 to answer the question whether the productive capacity of deep, dark prairie soils is inexhaustible. Each plot is about one-third acre but is further subdivided for special fertility treatments. The most meaningful comparison is between a corn-soybeans cropping system, which represents the conventional system, and a corn-oats-hay system, which is typical of an organic farming system.
The productivity of the two systems can be compared in three ways:
In terms of amount of feeding value of crops for livestock, the conventional (corn-soybeans) system was 7 per cent superior.
in terms of potential human food (assuming that grains can be eaten but hay must be processed through livestock), the conventional system exceeded the organic system by 41 per cent.
In terms of value of crops at prices received during the past 10 years, the corn-soybeans system exceeded the corn-oats-hay system by 43 per cent.
An organic farming system, if widely practiced in Illinois, would require large increases in the acreages of relatively low-valued, small grains and hay and a corresponding decrease in soybeans, which are valued much more highly by society under 1977 conditions.
The tradeoffs can be presented this way:
• Growing nitrogen in the form of forage legumes as a substitute for nitrogen fertilizer results in a saving of energy but a loss of food.
• Conventional farming systems convert more fossil energy into food than do organic farming systems.
• Attempting to offset a loss in amount of food per acre by increasing acreage would result in greater runoff, erosion and sediment pollution because of more cropland on steep slopes.
Researchers in the neighboring state of Iowa, which is much like Illinois, calculated that a shift from approximately the present farming system to an organic farming system would reduce production to the point where the value of crops at 1974-1976 prices would decline by nearly 32 per cent. The difference indirectly indicates the impact on consumers rather than on farmers. Food prices and prices received by farmers would rise dramatically because of declines in production.
A shift to organic farming has many important implications which will not be described in detail:
It would interfere with optimum land use on many farms.
It would prevent regional specialization of farming systems, thus reducing efficiency and causing problems in other sections of the country which purchase feed grains and soybeans from the Midwest.
It would reduce the amount of grains available for world export, thus cutting off a major item in our balance of trade with which to purchase oil.
Proponents of organic farming have suggested that returning animal manures and sewage sludge to the land could largely replace the need for fertilizers. They seem unaware that most animal manure is already returned to the land; furthermore, it is not a net
addition because the manure only contains fertilizer nutrients previously removed by crops. It is difficult to return more than one-fourth to one-half of the nitrogen in harvested crops. Human excrement in Illinois contains only 5 per cent as much nitrogen as is supplied in fertilizers. Nitrogen fertilizer in Illinois is, in fact, added by farmers to supplement but not replace the amounts available from soil humus, crop residues and manure.
The concept of organic farming is not new to Illinois. Early agriculture followed what is commonly now called organic farming. It prevailed within Illinois until about 1940. At that time, fertilizers supplied less than one-third pound of nitrogen per acre compared to an average of about 70 pounds in 1977.
The system was nearly in balance with respect to nitrogen requirements at the yield levels then attained. Since 1940, total crop production in Illinois has increased 230 per cent. Nitrogen that was adequate for the food production system in 1940 would be extremely deficient for the amount of crops grown in 1977, and even more deficient in future years.
About 100 years of farming under an organic farming system resulted in loss of approximately 40 per cent of the original soil organic matter and nitrogen. Fortunately, nitrogen fertilizer is now available to offset the decline in nitrogen from the soil.
Fertilizers at recommended rates increase both earthworms and soil bacteria by providing more plant residues to their food supply.
Recent news stories suggest that increased use of nitrogen fertilizer poses a long-term threat to the protective ozone layer in the stratosphere. It is important to understand that any strategy to increase the supply of nitrogen for food production, including capturing nitrogen by growing legume crops, has the same potential effect.
Many persons have been led to believe that the use of pesticides is more or less optional for commercial agriculture, that suitable biological control measures are available and that risks and benefits are in delicate balance. These claims are simply not yet true in 1977.
It can only be concluded that organic farming is not a viable system with which to meet food needs in today's world.
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