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- Problem~ in I l c A^r r 't r THE U S AGRICUUURAL SYSTEM has been beset by numerous economic and environmental problems in the l980s. In the economic sphere, with storage facilities filled with surplus crops, the cost of federal farm support programs skyrocketed from $3.5 billion in 1978 to a peak of $25.8 billion in 1986, falling to $22 billion in 1987 (U.S. Department of Agriculture, l98Sf). Financial stress hit tens of thousands of farmers and many rural communi- ties. Some farmers still find it difficult to pay debt accumulated during the prosperous 1970s. Many U.S. products are no longer competitive in world markets. From 1981 through 1986, the United States' agricultural trade surplus declined substantially. Although agricultural trade performance has improved since then, this has come at considerable expense to U.S. taxpay- ers. Competition among nations for worldwide markets is fierce and vola- tile. Agriculture is also causing serious environmental problems. Agriculture is the largest single nonpoint source of water pollutants, including sedi- ments, salts, fertilizers, pesticides, and manures. Nonpoint pollutants ac- count for an estimated 50 percent of all surface water pollution (Cheaters and Schierow, 1985; Myers et al., 1985~. Salinization of soils and irrigation water from irrigated agriculture is a growing problem in the arid West. In at least 26 states, some pesticides have found their way into groundwater as a result of normal agricultural practice. In California alone, 22 different pesticides have been detected in groundwater as a result of normal agricul- tural practices. Nitrate from agricultural sources (principally manures and synthetic fertilizers) is found in drinking water wells in levels above safety standards in many locations in several states. Agriculture presents other environmental problems. Major aquifers in California and the Great Plains have been depleted because withdrawals 89
90 ALTERNATIVE AGRICULTURE exceeded recharge rates. Cultivation of marginal lands has caused soil ero- sion. The use of certain pesticides on some crops and antibiotics in animal production for disease control and growth promotion presents risks that may be avoidable. Agricultural leaders and policymakers are currently confronting questions about contemporary production practices. These questions are the subject of this chapter. It is important to note that many problems discussed in this report are prevalent only in certain regions and under specific management practices. Almost ah of these problems can be overcome. Nonetheless, problems such as groundwater contamination wiD likely grow if current practices are continued. Many of these problems have developed in large part as a result of public policies and thus may be overcome through policy reform. The important link among all of these problems is that productive and profitable alterna- tive practices are available in most cases and are already implemented in some. The benefits of alternatives in addressing these problems are pre- sented in subsequent chapters. Publicly and privately funded agricultural research since World War II has created a wealth of technology and information. This information and tech- nology has led to vastly increased yields of a number of commodities and has reinforced movement toward specialization. High deficiency and disas- ter payments for most program crops reduced risks and further accelerated specialization. The development of specialized large farm equipment made it possible for individual farmers to grow one crop or a few related crops on more acres. Because of these trends, farmers were able to take advantage of market forces in the 1970s that stimulated demand for U.S. agricultural commodities. THE FARM ECONOMY In their desire to accelerate industrial growth, many developing countries neglected their agricultural sectors in the 1950s and 1960s. By the 1970s, a growing number of developing nations needed to import food to feed rap- idly growing populations. Many of them imported food from the United States. Growing trade with Pacific Rim nations and trade agreements with the Soviet Union further expanded available markets for the United States. The 1970s also brought generally favorable weather for agriculture to the United States and unfavorable conditions to many other countries. Tax policies such as accelerated depreciation and cap*al gains preferences en- couraged machinery purchases and cultivation and irrigation of previously uncultivated or erodible land. Crop prices were wed above the loan rate; expanded exports were used to offset the trade deficit created by oil im- ports. The result was greater demand for U.S. commodities, higher prices, and an all-out effort by U.S. farmers to increase production. Farmland prices followed the upward movement of commodity prices, inflation, and negative real interest rates. In some midwestern states, the
PROBLEMS IN U.S. AGRICULTURE 175 150 125 100 Oh :5 75 o 50 25 91 Gross farm income _ I//////////// Production expenses /// 01~ 1970 1972 1974 1976 1978 1980 1982 1984 1986 YEAR FIGURE 2-1 Gross farm income and production expenses. SOURCE: U.S. Department of Agriculture. 1988. 1988 Agricultural Chartbook. Agriculture Handbook No. 673. Washington, D.C. price of farmland increaser! by 15 percent or more per year. Rising land and commodity prices led farmers to increase purchases of inputs such as fertil- izers, seeds, chemicals, and equipment. Production expenses and gross farm income soared as farmers responded to a growing market (Figure 2-1~. Agricultural lending organizations, responding to inflation and rising mar- ket values of farm assets, were eager to make loans to farmers. Total farm debt went from $52.8 billion in 1970 to a peak of $206.5 billion in 1983 (U.S. Department of Agriculture, 1987c). In late 1979, events began to change the economic, political, and social environment of agricultural production. Policy changes caused increases in real interest rates and the virtual end of inflation. Prices received for crops began to level off and drop although input prices continued to rise through 1984 (Figure 2-2~. Demand for U.S. agricultural commodities declined as a result of the increased value of the doDar; fixed loan rates; foreign compe- tition from the European Community (EC), Argentina, Australia, and Bra- zil; foreign debt; global recession; and reduction of U.S. loans to developing countries to buy food. Commodity surpluses around the world sweDed, and prices dropped. Falling commodity prices deflated land values, which fell by 1986 to less than half their 1980 value in many agricultural areas. In a few years, prosperity turned into economic recession. Many farmers borrowed heavily in the 1970s to invest in land and machinery and take
92 ALTERNATIVE AGRICULTURE 50 40 In o . _ Q 30 G In 5 20 o 10 o Prices paid for inputs ]~ ~ Prices received for crops. ~ ~~ qL U.S. agricultural exports ~ by, :..... ......... ............ .: ......... ~:~ 1976 1978 1980 1982 1984 1986 YEAR 175 - 1 50 `' a, Q G 125 Oh LL] 1 00 0 50 FIGURE 2-2 Input prices, crop prices, and agricultural exports. SOURCE: U.S. Department of Agriculture. 1988. 1988 Agricultural Chartbook. Agriculture Handbook No. 673. Washington, D.C. advantage of high crop prices. The sudden change in the economic environ- ment placed those with the greatest debt in the most vulnerable position. The debt-to-asset ratio suddenly became a major criterion for a farm's viability. The financial plight of farmers also affected the farm credit sector. One- fourth of ah farm loans $33.7 billion from the Farmers Home Administra- tion (FmHA), federal land banks, production credit associations, commer- cial banks, and life insurance companies were nonperforming or delinquent in 1984 and 1985 (U.S. General Accounting Office, 1986a). The farm credit system lost $4.6 billion in 1985 and 1936. Agricultural banks accounted for more than half of 1985 bank failures, although they comprise only one- fourth of aD banks (U.S. General Accounting Office, 1986a). New rules to implement the Agricultural Credit Act of 1987, however, will help to keep tens of thousands of farmers on their land. The act requires the FmHA, the farmers' bank of last resort, to make aD feasible efforts to restructure loans, including forgiving debt. Up to $7 billion in debt and interest may be written off under this program. Suppliers of farm inputs have also been hurt by bad debt and federal supply-control programs that have reduced sales. Farm machinery sales, for example, fen more than 50 percent from 1980 to 1985. In Nebraska and lowa alone, hundreds of farm implement dealers have gone out of business since 1935. The industry has recovered somewhat since 1986 as farm income has risen. As of January 1, 198S, 4 percent of farms were technically insolvent be-
PROBLEMS IN U.S. AGRICULTURE 93 cause debt exceeded assets. An additional 4.9 percent of farms had debt-to- asset ratios of 70 to 100 percent, and 10.0 percent had debt-to-asset ratios of 40 to 70 percent (U.S. Department of Agriculture, 1988~. Farms with ratios above 70 percent generally experience serious financial problems. Those with debt-to-asset ratios of 40 to 70 percent face declining equity unless commodity prices are strong or production expenses fall, which they have since 1983. Although some farmers experienced financial hardship in the 1980s, many prospered. Total net farm income was $37.5 billion in 1986 and a record $46.3 billion in 1987 (see Figure 1-29~. Off-farm income totaled a record $44.7 billion in 1986 (Van Chantfort, 1987~. Table 2-1 shows that most farms had positive income in 1987, and that debt is now concentrated in farms with sales over $250,000. This recorc! income and reduction in debt was made possible, however, only by record levels of government support. In 1987, 44 percent of aD farmers had no long-term debt. The average debt-to-asset ratio, which reached 25 percent in 1985, fen to 22 percent in 1986 and 15 percent in 1987 (Figure 2-3~. Total farm debt fell from $206.5 billion in 1983 to $150 billion in 1988 (U.S. Department of Agriculture, 1988a). Federal programs can have a great effect on the agricultural economy. In general, they are slow to alleviate the economic problems of farmers with the greatest need. This has been evident in the 1980s. WeD over one-half of all major commodity producers have been enrobed in the programs since 1983. But 60 percent of direct government payments in 1985, for example, went to only 14 percent of all operators with net cash incomes averaging nearly $130,000 (Agricultural Policy Working Group, 1988~. This is largely because federal payments are based on farm yields and sales. Even though Congress has limited certain categories of federal payments to $50,000 per farm, many growers have found ways to reorganize their operations to avoid this and other limitations. TRADE U.S. agriculture built a substantial trade surplus during the 1970s as the manufactured goods sector slipped into a deepening trade deficit. The U.S. agricultural trade balance deteriorated in the 1980s, however, falling from $27 billion in 1980 to $6 billion in 1986 (U.S. General Accounting Office, 1986b). The United States depends primarily on grain and oil seed exports; growth in this market is slowing as the U.S. share declined from 72 percent in 1979 and 1980 to 50 percent in 1986 (U.S. Department of Agriculture, 1986b). The trade situation has improved since 1986; exports are expected to increase to about $33 billion in 1988, with the trade surplus rising to be- tween $12 billion and $13 billion. The U.S. agricultural trade balance has increased, in part because of a drop in market prices for most export com- modities. Government subsidies, credit guarantees, and product promotion
94 ALTERNATIVE AGRICULTURE TABLE 2-1 Farm Financial Conditions by Farm Size, Region, and Commodity Percentage of Farms in Each Financial Condition . Favorable Negative Marginal Vulnerable (Positive Income Income- Solvency- (Negative Income and Favorable Favorable Positive and Marginal Factor Solvency) Solvency Income Solvency) Farm size 2 $250,000 59 14 20 7 $40,000-249,999 64 12 17 6 < $40,000 71 19 6 4 Region - Northeast 68 22 7 3 Great Lakes 59 1 15 7 Com Belt 71 12 13 5 Northern Plains 64 17 15 5 Appalachia 76 16 5 3 Southeast 73 18 6 4 Delta 72 16 8 4 Southern Plains 69 20 8 4 Mountain 64 20 10 6 Pacific 67 18 9 7 Farm type Cash grain 65 14 14 7 Tobacco 78 9 8 5 Cotton 65 11 15 9 Vegetable, fruit, nut 71 16 9 3 Nursery-greenhouse 80 12 6 2 Other field crops 65 17 10 7 Beef, hog, sheep 70 20 7 3 Dairy 63 12 20 5 Poultry 73 6 16 6 Other livestock 58 30 5 7 NOTE: The income measure used in these statistics is net cash farm income; marginal solvency indicates a debt-asset ratio of 40 percent or more. Favorable solvency indicates a debt-asset ratio of 40 percent or less. Adding across, numbers may not total exactly to 100 percent because of rounding. SOURCE: U.S. Department of Agriculture. 1988. Financial Characteristics of U.S. Farms, January 1, 1988. Agriculture Information Bulletin No. 551. Economic Research Service. Washington, D.C. also supported increased exports. The rise in export volume, however, far exceeded the increase in the value of exports in current doDars largely due to the declining value of the dollar (Figures 2-4 and 2-5) (U.S. Department of Agriculture, 1987e). Meanwhile, the United States is increasing its imports of high-value prod- ucts such as processed foods and horticultural products. The United States accounts for about 10 percent of the value of world trade in high-value markets, primarily through exports of soybean meal, tobacco, cigarettes, cattle hides, and corn-gluten feed. Imports of supplementary high-vaTue commodities (crops also produced in the United States) have increased from
Pfi by C) 111 20 95 / ' / ' o 1 970 Net cash income to total farm debt An. Farm debt-to-asset ratio - 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ,1 1 1975 1980 1985 86 87 YEAR FIGURE 2-3 Farm debt-to-asset and net-cash-income-to-total-farm-debt ratio. Data exclude households. SOURCE: U.S. Department of Agriculture. 1988. 1988 Agricultural Chartbook. Agriculture Handbook No. 673. Washington, D.C. 180 160 140 120 100 / ~ / - - - 80 1 1 1 1 1 1 1 1 1 1 1 977 -
96 180 160 140 An LL i, 1 20 100 80 ALTERNATIVE AGRICULTURE J - 1 , 1 1 1 1 1 1 1 1 1 1977 1979 1981 1983 1985 1987 YEAR FIGURE 2-5 Value of U.S. agricultural exports. SOURCE: U.S. Department of Agriculture. 1988. 1988 Agricultural Chartbook. Agriculture Handbook No. 673. Washington, D.C. 15[ in Cat .° 10 ._ Q · _ On J o C] o 1977 1979 1981 1983 Total Tobacco ~ ~ Other I. · .;. \ ~ ~ Fruits, nuts, and vegetables / _ ///// ~//J//~ ITCH I 171 ~ Veins and beer Sugar lLLLLLL1 1 1 1 no! ·-~ YEAR 1985 1 987 FIGURE 2-6 Value of supplementary commodity imports. SOURCE: U.S. Department of Agriculture. 1988. 1988 Agricultural Chartbook. Agriculture Handbook No. 673. Washington, D.~.
PROBLEMS IN U.S. AGRICULTURE 80 LL] 6 ILI z ~ 60 llJ C.) () Z IL ~ lo 6 ~ 40 ~ O O ~ Q IL ~ O cD 20 o 97 1986 1 982 r ·~. _ :-:. Fit . . ~ i, i-`,: ~ ~ . of' g`, '` `'4'3 `~ ,\ ~C, ~ l ~~- 2~'> ,\' ,\ Id, \,~',~, ,,3 a,\_ !~:,_`, ~ ',, ,,%~`, _~; c'`,%\C, ': 1 984 Am.- ~ . ,,- :-:-:~: '/ .22'' f :-:-:. '/ . .,..-. ~ ·:-:. ,, ~ of. ·~e ~ ~ ·:-:- /, . a::-: ,, ; .-.-. ~ , ~ , .-.. ~ . . ,..-..., ~ al, ,,' ,,,'' ~,~,21 'age,,\ a.`, t1t2 ,',,'i ,',\;2i ,~,,,~, . United States European Canada Community COUNTRIES Japan FIGURE 2-7 Average producer subsidy equivalents for grains, livestock, dairy, oilseeds, and sugar. The European Community is Belgium, Denmark, France, Greece, Ireland, Italy, Luxembourg, the Netherlands, Portugal, Spain, the United Kingdom, and West Germany. SOURCE: U.S. Department of Agriculture. 1988. 1988 Agricultural Chartbook. Agriculture Handbook No. 673. Washington, D.C. $7 billion in 1977 to almost $14 billion in 1987 (Figure 2-6~. The total value of agricultural imports reached $20 billion in 1987. Increasing competition is also contributing to the rising cost of federal agricultural subsidies. The government spent $25.S billion in 1986 and $22.0 billion in 1987 for price supports and related activities. Of this amount, $11.S billion in 1986 and $16.7 billion in 1987 were direct payments to farmers (U.S. General Accounting Office, 1988~. Nonetheless, U.S. agricul- tural subsidies as a percentage of producer income are far less than those of the EC, Canada, and Japan (Figure 2-7~. NATURAL RESOURCES The diversity in plant and animal products produced in the United States has increased in the past three decades, but individual farms have become more specialized. Technology has contributed to a shift from multi-enter- prise farming operations to those having as few as one or two income-
98 ALTERNATIVE AGRICULTURE generating crops or products. Recently, however, this trend of specialization has slowed down. Over the past decade, many farmers have adopted alter- native methods more consistent with the goals of profitability with less government support and greater natural resource and human health protec- tion. The following section is a brief review of the adverse consequences that some current agricultural practices have on natural resources and the envi- ronment. It must be emphasized that many conventional agricultural prac- tices are environmentally sound and are components of certain alternative strategies. The following analyses are not intended to be fully comprehen- sive; however, they do illustrate the factors that must be considered in any agricultural production system. Water Quality Surface Water Water pollution is probably the most damaging and widespread environ- mental effect of agricultural production. Agriculture is the largest nonpoint source of water pollution, which accounts for about half of all water poDu- tion (Cheaters and Schierow, 1985; Myers et al., 1985~. Under sections 304(f) and 305(b) of the Clean Water Act of 1972 as amended, 17 states and Puerto Rico identified agriculture as a primary or major nonpoint source of water pollution, and 27 states and the Virgin Islands identified it as a problem (Table 2-2) (U.S. Environmental Protection Agency, 1984~. Surface water damage from agriculture is estimated at between $2 billion and $16 billion per year. These estimates are approximate, however, and may underesti- mate the long-term costs of pollution. Precipitation- and irrigation-induced runoff carries sediment, minerals, nutrients, and pesticides into rivers, streams, lakes, and estuaries. Most experts consider erosion's effects on water resources to be greater than its potential effects on productivity (National Research Council, 1986c; Schnei- der, 1986~. The U.S. Department of Agriculture (USDA) calculates that the economic cost of off-farm water pollution due to agricultural erosion is from two to eight times the value of erosion's effect on productivity (U.S. De- partment of Agriculture, 1987a). This comparison, however, is crude. Sediment deposition and nutrient loading are major agricultural water pollution problems (CIark et al., 1985; U.S. Department of Agriculture, 1987a). Agriculture accounts for more than 50 percent of suspended sedi- ments from ad sources discharged into surface waters (U.S. Department of Agriculture, 1987a). In predominantly agricultural regions, these percent- ages are higher; in other regions, agriculture's contribution is less. Nation- wide trends in surface water sediment deposition between 1974 and 1981 were significantly related to cropland erosion within basins. They were not closely related to estimates of total basin erosion from forestIand, pasture- land, or rangeland (Smith et al., 1987~.
PROBLEMS IN U.S. AGRICULTURE TABLE 2-2 Agriculture (Including Feedlots) as a Nonpoint Source of Water Pollution by State or Territory Agriculture Identified as a Primary or Major Nonevent Source of Water Pollution 99 Agriculture Identified as a Nonpoint Source Pollution Problem Delaware Montana Alabama Nevada Idaho North Dakota Arizona New~ersey Illinois Ohio Arkansas New Mexico Indiana Oregon California New York Iowa Puerto Rico Colorado North Carolina Kansas South Dakota Florida Oklahoma Kentucky Utah Georgia Pennsylvania Minnesota Vermont Hawaii South Carolina Mississippi Washington Louisiana Tennessee Maine Virgin Islands Maryland Virginia Michigan West Virginia Missouri Wisconsin Nebraska Wyoming - SOURCE: U.S. Environmental Protection Agency. 1984. Report to Congress: Nonpoint Source Pollution in the U.S. Office of Water Program Operations, Water Planning Division. Washington, D.C. The principal consequence of sediment loading is increased turbidity, which causes decreased light for submerged aquatic vegetation. Species that depend on aquatic vegetation for breeding and food can thus experi- ence stress and decline. Sediment also has direct economic consequences when it fills reservoirs, clogs navigable waterways, reduces recreational use of waters, and increases operating costs of water-treatment facilities. Be- tween 675 million anct 1 billion tons of eroded agricultural soils are depos- ited in waterways each year (National Research Council, 1986c; Schneider, 1986; U.S. Department of Agriculture, 1986a). The USDA (l98Se) estimates that the removal from production of 30 minion to 40 minion acres of highly erodible land through the Conservation Reserve Program (CRP) will reduce sediment delivery to surface waters by as much as 200 million tons per year. Phipps and Crosson (1986) and the USDA (1987a) estimate that between 50 and 70 percent of all nutrients reaching surface waters, principally nitro- gen and phosphorus, originate on agricultural land in the form of fertilizer or animal waste. Nitrate, which is relatively soluble, is carried in solution by water; phosphorus is most often carried attached to sediment. From 1974 to 1981, 116 stations from the National Stream Quality Accounting Network and the National Water Quality Surveillance System reported increasing nitrate concentrations; only 27 stations reported decreases. Ele- vated nitrogen levels were strongly associated with agricultural activity and atmospheric deposition of nitrogen in rainfall. Phosphorus deposition has been less consistently observed because increases are closely linked to levels of suspended sediments. Nitrate moves with water; thus, nitrogen move-
loo ALTERNATIVE AGRICULTURE Flooding and extensive water runoff carry of all nonpoint surface water pollution. sediment, fertilizers, and pesticides into Flooding can also severely damage crops, surface water. Agriculture contributes one-half land, and buildings. Credit: Agrichemical Age. ment into surface waters more fully reflects the effects of agricultural activ- ity than phosphorus movement does. Phosphorus moves as a passenger bouncl with sediment, much of which erodes from fields but is not depos- ited in surface waters (Smith et al., 1987~. Nutrient loading has had a devastating effect on many lakes, rivers, and bays throughout the country. Increased nutrient levels, particularly of phos- phorus, stimulate algal growth, which can accelerate the natural process of eutrophication. In its later stages, the algal growth stimulated by nutrients will die and decay, which can significantly deplete available oxygen and reduce higher-order aquatic plant and animal populations. The accelerated eutrophication of the Chesapeake Bay is an excellent example of the conse- quences of nutrient loading from agricultural and municipal sources. Nutri- ent loading in the bay has contributed to a significant decline in the bay fisheries (Kahn and Kemp, 1985~. Sediment and nutrient runoff from agricultural land plays a part in estu- ary degradation. For 78 estuaries examined by the USDA, agricultural run- off supplied on average 24 percent of all nutrient loacting and 40 percent of total sediment. In 22 of the 78 estuaries, agriculture contributed more than
PROBLEMS IN U.S. AGRICULTURE 101 25 percent of total nitrogen and phosphorus pollution. High rates of pesti- cide runoff (greater than 30 percent above the average of all coastal states) were found in 21 estuary systems. High nutrient and pesticide runoffs were found in 15 systems (U.S. Department of Agriculture, 198Sb). Between 450 million and 500 million pounds of pesticides are applied to row crops each year. The majority of these are herbicides, most of which are applied before planting, and many of which are incorporated into the soil. Probably less than 5 percent of all pesticides applied reach a body of water (Phipps and Crosson, 1986~. The highest concentrations of pesticides are related to agricultural runoff into streams and lakes. In intensively farmed states, such as Iowa, Minnesota, and Ohio, a number of the widely used corn and soybean herbicides have been detected in rivers, many of which serve as drinking water sources. In humid areas where groundwater contributes a major proportion of stream flow, some herbicides may be delivered to surface water via groundwater (HalIberg, 1987~. It appears that many of these herbicides are not effectively removed from drinking water by conventional treatment or more sophisticated carbon filtration systems (Table 2-3~. Maximum and mean levels of 10 herbicides detected in treated drinking water in Ohio and Iowa are shown in Table 2-4. In Iowa, 27 of the 33 public water supplies from surface water sources tested, or 82 percent, tract 2 or more pesticides detected in treated drinking water samples; 73 percent had 3 or more; 58 percent had 4 or more; and 21 percent had 5 or more (Table 2-5~. These samples were collected after rainfall between mid-April and July 30, 1986, when most herbicides are applied; consequently, they may represent a peak of exposure to those compounds. The mean detection levels were below 4.0 parts per billion (ppb). Samples collected and analyzed by Monsanto between May 1985 and March 1986, however, had only slightly lower percentages of detection for all herbicides except alachior, which was far lower, in treated drinking water from surface water sources (Wnuk et al., 1987~. Glenn and Angle (1987) studied the effect of tiliage systems on runoff of the herbicides atrazine and simazine in the Chesapeake Bay watershed. There was less runoff of water, atrazine, and simazine from the untilled fields compared to conventionally tilled fields each year that a major rain occurred during the growing season. From 1979 through 1982, total runoff from fields in the untilled watershed was 27 percent less than that from the conventionally tilled watershed. The highest levels of atrazine in runoff water were 1.332 micrograms/liter and 0.975 micrograms/liter in conven- tional tilIage and no-tilIage systems, respectively, or 1.6 and 1.1 percent of atrazine applied at 2 pounds/acre. The highest reported runoff of simazine at 2 pounds/acre was 0.456 micrograms/liter or 0.5 percent for conventional tildage and 0.210 micrograms/liter or 0.36 percent of the total applied for no tiliage. Most of the runoff occurred within 2 weeks of application. In 1981 and 1982, when rainfall was delayed more than 2 weeks, levels declined substantially. Losses of up to 16 percent for atrazine and up to 3.5 percent for simazine have been reported (Glenn and Angle, 1987~.
102 ._ hi o Cal ~ ,c = ~ ,c to ~ 8 ~ ~ o o - o == ~ o c~ I :o .= ~ ~ ~ Cal Lo oo u, ~ ~ ~ d4 ~ ~ o ~ $ o Cal o ~ ~ At ~ Dot Cal Cal Cat ~ ~ U) a: Dot d4 .- o ~ Go o An, - o - L~ lo - d4 ~ us I i` ~ us AD ~ c~ ln oo C~ ~ 0 ~ _ _ _ _ r) a: ~ _ _ _ ~ U~ oo _ _ _ C~ ~ C~ ~5 Ct ~ ~ ~ 0 o _1 . . Ct ~4 o a, U. ~ 3 . - U. .= n U. ~ ~ .~ C U: G C,, to cn _ ~ ~ N di . ~ it O ~ ~ =0 ·m a) ~ ~ > 3 3 ~ o o ~ '~ C _ ~ ~ ~ 0 ~0 Ct~ ~ #- v e `~s ~S ~ ~ ~o ~ ~ ~ ~- ~ ~ ~ ~ o e ~ e ~ '~s .= ~ ~ =~o ~ ~ U, ~ ~ z ~ E ~ ~ U, o cn
PROBLEMS IN U.S AGRICULTURE 103 TABLE 2-4 Pesticide Concentrations From Finished (Treated) Public Drinking Water Supplies Derived From Surface Waters (in m~crograms/liter) Maximum Residues Detected' Reported Iowa City' Iowa, Pesticide Ohio Iowa Mean In Iowa May 18-19, 1986 Herbicides Alachlor 14.3 8.8 1.1 8.8 Atraz~ne 30.0 24.0 3.8 15.0 Butylate 0.3 0.27 Cyanaz~ne 2.4 17.0 2.7 7.2 2,4-D 0.2 0.23 0.2 Dicamba 1.4 1.4a Neuron 0.6 Metolachlor 24.2 21.0 2.9 10.0 Metribuzin 0.3 0.29 0.3 Simazine 1.0 Trifluralin 0.1 0.13a Insecticide Carbofuran 14.0 - 6.0 NOTE: Maximum levels reported from studies in Ohio (D. Baker, 1985) and Iowa (M. Wnuk et al., 1987), and multiple residues in Iowa City, Iowa, tap water May 18-19, 1986. aOnly one detection (see Table 2-3). SOURCES: Baker, D. B. 1985. Regional water quality impacts of intensive row-crop agriculture: Lake Erie Basin case study. Journal of Soil and Water Conservation 40(1~:125-132; Hallberg, G. R. 1987. Agricultural chemicals in ground water: Extent and implications. American Journal of Alternative Agriculture 2(1):3-15; Kelley, R. D. 1987. Pesticides in Iowa's drinking water. Pp. 115-135 in Pesticides and Groundwater: A Health Concern for the Midwest. Navarre, Minn.: The Freshwater Foundation and U.S. Environmental Protection Agency; Wnuk, M., R. Kelley, G. Breuer, and L. Johnson. 1987. Pesticides in Water Supplies Using Surface Water Sources. Iowa City, Iowa: Iowa Department of Natural Resources and University Hygienic Laboratory. The USDA predicts that pesticide and fertilizer use may be reduced by 61 million pounds and 1.4 minion tons, respectively, from 1985 levels as a result of land idled under the CRE Because idled land is highly erodible, the reduction in fertilizers and pesticides reaching surface water through runoff may be proportionally greater as a percentage of total pesticides and fertilizers applied (U.S. Department of Agriculture, 198Se). Declining but detectable levels of many chlorinated hydrocarbon pesti- cides are still found in several fish, shellfish, and bird species and water- borne sediments, particularly in the Great Lakes (Hileman, 1988~. Levels of dichioro dipheny! trichIoroethane (DDT) in fish contributed to a dramatic decline in predatory bird populations, such as the peregrine falcon, osprey, and bald eagle in the 1960s and 1970s. The use of most persistent organo- chIorine pesticides has been phased out in the United States, although they continue to enter the environment as inert ingredients in a few currently used pesticides, and through their continued use worldwide. Some of these compounds are carried through the atmosphere and deposited far from rig
104 ALTERNATIVE AGRICULTURE TABLE 2-5 Number of Pesticides Detected in Treated Drinking Water Samples in Iowa Number of Percentage of Water Individual Supplies in the Study Pesticides Number of Supplies Containing an Equal or Detected in with the Number of Population (number) Greater Number of Treated Water Pesticides Listed Served by These Pesticide Residues Samples in Column 1 Supplies Listed in Column 1 2 5 7 3 136,725 91 3 2,828 82 5 33,222 73 12 115,485 58 3 239,386 21 3 15,874 9 1 20,000 3 SOURCE: Wnuk, M., R. Kelley, G. Breuer, and L. Johnson. 1987. Pesticides in Water Supplies Using Surface Water Sources. Iowa City, Iowa: Iowa Department of Natural Resources and University Hygienic Laboratory. their point of application. The presence of toxaphene, chIordane, and other chlorinated hydrocarbon compounds in the Great Lakes is an example of this phenomenon (Hileman, 1988~. The U.S. Environmental Protection Agency (EPA) (1987) reports that other pesticides, notably the herbicide alachIor, have been detected at up to 6.59 ppb in rainwater. Mineralization and salinization of soils and irrigation wastewater are growing problems in irrigated agriculture, primarily in the West. Soil saTi- nization and mineralization reduce crop yields, and, if not corrected, wiD ultimately leave the land unfit for agricultural purposes. The adverse repro- ductive effect of selenium on waterfowl in the Kesterson wildlife refuge in California is the most publicizes! example of the nonagricultural effects of salinization. The salinization and depletion of the Colorado River from its use as agricultural irrigation water throughout its course is perhaps the most vivid example of agriculture's effect on water quality and quantity in the West. Amendments to the Clean Water Act in 1987 require states to report their principal nonpoint sources of water pollution and programs in place to mitigate the problem. The act does not require implementation of measures to reduce nonpoint source pollution of surface waters, however. In 198S, the USDA's National Program for Soil and Water Conservation and the Rural Clean Water Program conducted 22 water quality improvement proj- ects arounc! the nation. Other provisions of the Food Security Act of 1985, such as the CRP and conservation compliance, will also help reduce agri- cultural nonpoint surface water pollution. Incentives integrated into agri- cultural conservation and commodity programs will likely remain the most effective way to reduce surface water pollution from agricultural sources, in lieu of further amendments to the Clean Water Act or regulations promul- gated under the act.
PROBLEMS IN U.S. AGRICULTURE Groundwater 105 Groundwater is the source of public drinking water for nearly 75 million people. Private water wells supply water to an additional 30 million individ- uals. Nearly 50 percent of all drinking water, 97 percent of all rural drinking water, 55 percent of livestock water, and more than 40 percent of all irriga- tion water is from underground sources. Accumulating evidence indicates that a growing number of contaminants from agricultural production are now found in unclerground water supplies (National Research Council, 1986b; U.S. Department of Agriculture, 1987b, 1987~. Increased use of nitrogen fertilizers and pesticides, particularly herbi- cides, over the past 40 years has raised the potential for grounclwater con- tamination. Greater use of feedIots that concentrate manure production also heightens this risk. Several of the most widely used pesticides have the potential to leach into groundwater as a result of normal agricultural use. The EPA has initiated a nationwide survey of pesticides in groundwater with results anticipated in 1990. The high-priority pesticides in that survey are listed in Table 2-6 (U.S. Department of Agriculture, 1987~. Pesticides have been detected in the groundwater of 26 states as a result of normal agricultural practices (Williams et al., 1988~. The most commonly detected compounds are the herbicide atrazine and the insecticide aldicarb. Aldicarb, the most acutely toxic pesticide registerer! by the EPA (LD50*, 0.9 milligrams/kilogram), has been found in 16 states; in many states, however, detections are isolated. Atrazine, the second most used herbicide in the nation, has been found in the groundwater of at least 5 states, usually at levels between 0.3 and 3.0 micrograms/liter. Tests show that atrazine is oncogenic in laboratory rats. The EPA is currently reviewing these studies but has not yet classified atrazine as an oncogen. The herbicide alachIor, recently banned in Canada and classified by the EPA as a probable human carcinogen, is the next most commonly detected pesticide in groundwater. It has been found in 12 states at a median concentration of 0.90 micrograms/ liter. Pesticides detected in groundwater as a result of agricultural use in 26 states are listed in Table 2-7. Pesticides detected in groundwater used for drinking water in Iowa and Minnesota are listed in Table 2-~3. A survey by the U.S. Geological Survey (USGS) of 1,663 counties showed 474 counties in which 25 percent of the wells tested had nitrate-nitrogen (NO~N) levels in excess of 3 milliarams/liter (Figure 2-~3~. Levels above 3 ~ ~ , .... .... . . . . . . . . . . . . . mullgrams/llter are considered elevated by human activities, primarily ni- trogen fertilizer use (Nielsen and Lee, 19~37~. In 87 of the 474 counties, at least 25 percent of the sampled wells exceeded the EPA's 10 milligrams/liter interim standard for nitrate in drinking water. Prolonged exposure to levels exceeding this standard can lead to methemogIobinemia (oxygen deficit in the blood), although reported instances of this condition have been rare. The USDA (1987c3) predicted that wells in an additional 149 counties may *LD50, or the Lethal Dose 50, is the dose of a substance that kills 50 percent of the test animals exposed to it. The lethal dose can be measured orally or dermally.
106 ALTERNATIVE AGRICULTURE TABLE 2-6 Priority Pesticides in EPA's National Survey of Pesticides in Groundwater (in thousands of pounds) Estimated Pesticide Thea User EPA Description Acifluorfen H 1,399 Leacher Alachlor H 85,015 Leacher Aldicarb I, N 2,271 Mobile; marginal persistence Ametryn H 96 Leacher Atrazine H 77,316 Leacher Bentazon H 8,410 Leacher; toxicological concern Bromacil H 1,234 Leacher Butylate H 55,095 Mobile; uncertain persistence; toxicological concern Carbofuran I, A, N 7,695 Leacher Chloramben H 6,069 Leacher Chlordane I 11 Persistent; possible direct con- tamination via termiticide use Cyanazine H 21,626 Leacher Cycloate H 52 Mobile; uncertain persistence; toxicological concern 2,4-D H 37,217 Marginal leacher; heavy use Dalapon H 261 Leacher DCPA H 196 Leacher Dicamba H 4,158 Leacher Dinoseb H 8,835 Leacher Diphenamid H 698 Marginal leacher; toxicological data gaps Disulfoton I, A 2,105 Leacher Diuron H 1,861 Leacher Fenamiphos I, N 348 Moderate leacher; toxicological concern Fluometuron H 2,943 Leacher Hexazinone H 11 Leacher Maleic hydrazide H 287 Leacher; toxicological data gaps MCPA H 9,861 Marginal leacher Methomyl I 425 Leacher Metolachlor H 37,940 Leacher Metribuzin H 10,603 Leacher Oxamyl I, A, N 51 Leacher Picloram H 549 Leacher Pronamide H 83 Leacher Propazine H 1,287 Leacher Propham H 445 Leacher Simazine H 3,975 Leacher 2,4,5-T H 204 Marginal leacher 2,4,5-TP H 7 Marg~nal leacher Terbacil H 833 Leacher aAbbreviations: A = acaricide; H = herbicide; I = insecticide; N = nematicide. bThousands of pounds of active ingredient per year used for agricultural purposes only. SOURCE: U.S. Department of Agriculture. 1987. The Magnitude and Costs of Groundwater Contamination From Agricultural ChemicalsA National Perspective. Staff Report AGES870318. Economic Research Service. Washington, D.C. .,
PROBLEMS IN U.S. AGRICULTURE TABLE 2-7 Confirmed Pesticide Detections in Groundwater Due to Normal Agricultural Use 107 Health Advisory Median Levela Concentrationb Pesticide (parts per billion) States (parts per billion) Alachlor 1.5c CT, FL, IL, IA, KS, LA, MA, 0.90 ME, NE, PA, WI Aldicarb 10 CA, FL, MA, NC, NY, RI, WI 9.00 Aldrin MS, SC 0.10 Arsenic TX N/A Atraton MD 0.10 Atrazine 3.0 CA, CO, CT, IL, IA, KS, MD, 0.50 ME, NE, N1, PA, VT, WI BHC MS 2.70 Bromacil 80 CA, FL 9.00 Carbofuran 36 MA, NY, RI 5.30 Chlordane 0.03C MS 1.70 Chlorothalonil 1.5c ME, NY 0.02 Cyanazine 9.0 IA, LA, MD, NE, PA, VT 0.40 1,2-D 0.0013 CA, CT, MA, NY 4.50 1,3-D 0.20C NY 123.00 2,4-D 70 CT, MS 1.40 DCPA 3,500 NY 109.00 DDT MS, NJ, SC 1.70 Diazinon 0.63 MS 162.00 Dibromochloropropane 0.02C AZ, CA 0.01 Dicamba 9.0 CT, ME 0.60 Dieldr~n 0.00219 NE, N] 0.02 Dinoseb 7.0 MA, ME, NY 0.70 Diuron 14 CA N/A Endosulfan ME 0.30 Ethoprop NY N/A Ethylene dibromide 0.0005C CA, CT, GA, MA, NY, WA 0.90 Fonofos 14 IA, NE 0.10 (Table 2-7 continued on page 108) have contaminated water based on high susceptibility to contamination and fertilizer use (Figure 2-9) (Nielsen and Lee, 1987~. The USDA calculates that 1,437 counties, or 46 percent of all U.S. coun- ties, contain groundwater susceptible to contamination from agricultural pesticides or fertilizers (Figure 2-10~. An estimated 54 miBion people living in these counties rely on uncLerground sources of drinking water. The costs or benefits of decontaminating this water are not currently quantifiable. It is likely, however, that contamination in certain regions will persist for many years after remedial actions are taken (Nielsen and Lee, 1987~. Several states (including California, Florida, Towa, New York, and Wisconsin) have devel- oped strategies for dealing with agriculturally induced groundwater con- tamination. But changes in agricultural practices to reduce groundwater contamination are not widespread. The EPA is also developing a national
108 TABLE 2-7 (Continued) ALTERNATIVE AGRICULTURE Health Advisory Median Levela Concentrationb Pesticide (parts per billion) States (parts per billion) Hexaz~none 210 ME 8.00 Lindane 0.026 MS, N], SC 0.10 Linuron WI 1.90 Malathion MS 41.50 Methamidophos ME 4.80 Methomyl 175 NY N/A Methyl parathion 2.0 MS 88.40 Metolachlor 10 CT, IL, IA, PA, WI 0.40 Metribuzin 175 IL, IA, KS, WI 0.60 Oxamyl 175 MA, NY, RI 4.30 Parathion ND 0.03 Picloram 490 ME, ND, WI 1.40 Prometon 100 TX 16.60 Propazine 14 NE, PA 0.20 Simazine 35 CA, CT, MD, NE, N), PA, VT 0.30 Sulprofos IA 1.40 TDE 0.031 MS 4.80 Toxaphene MS 3,205.00 Trifluralin 2.0 KS, MD, MS, NE 0.40 aThe EPA sets the Proposed Lifetime Health Advisory Level. The EPA has not set levels for all pesticides. Median of the concentration of positive detections for all confirmed studies. If multiple studies were not done on a particular chemical, the single study average is given. If the data base reports a single positive well, then the average concentration reported for that well is given. CFor carcinogens, the Proposed Lifetime Health Advisory Level is based on the exposure levels that present a 1 in a million risk of cancer in the exposed population. SOURCE: Williams, W. M., ~ W. Holden, D. W. Parsons, and M. N. Lorber. 1988. Pesticides in Ground Water Data Base: 1988 Interim Report. Office of Pesticide Programs. U.S. Environmental Protection Agency. Washington, D.C. groundwater protection strategy. Once the EPA's ongoing survey of pesti- cides in groundwater is complete, additional time win be needed to carry out detailed risk-benefit assessments required by the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). The committee notes that oppor- tunities exist today to reduce surface water and groundwater contamination from agricultural chemicals through modified agricultural practices. Some of the modifications include increased use of legumes as a nitrogen source, adoption of integrated pest management (IPM), or shifts in regional crop- ping patterns. The Effects of Irrigation Irrigated agricultural acreage doubled from 25 million acres in 1949 to slightly more than 50 million acres in 1978. Since then, total irrigated acre-
PROBLEMS IN U.S. AGRICULTURE TABLE 2-8 Pesticides Detected in Underground Drinking Water Supplies in Iowa and Minnesota 109 Maximum Concentration Mean Percentage of (micrograms/liter) in Concentration Detections in Common Name of Iowa and (micrograms/liter) in Iowa and Active Ingredient Minnesotaa Iowa and Minnesota Minnesotaa Herbicides Alachlor 16.6/9.8 0.5 15/11 Atrazine 21.1/42.4 0.2 72/72 Chloramben 1.7/N.D. - < 1/0 Cyanazine 13.0/0.10 0.5 12/1 2,4-D 0.2/4.2 0.2 < 1/2 Dicamba 2.3/2.1 0.3 2/2 Metolachlor 12.2/2.1 0.5 10/2 Metribuzin 6.8/0.78 0.5 9/2 Picloram N.D./0.13 0/1 Propachlor 1.7/0.52 0.3 1/3 Simazine N.D./2.6 0/ < 1 2,4,5-TP N.D./0.26 0/1 Trifluralin 0.2/N.D. 1/0 Insecticides (and nematicides) Aldicarb N.D./30.6 0/ < 1 Carbofuran 0.06/N.D. 2/0 Chlorpyrifos 0.07/0.21 0.1 < 1/2 Fonofos O.90/N.D. 0.2 1/0 Phorate O.10/N.D. < 1/0 NOTE: N.D. means not detected. A dash indicates insufficient data to calculate mean. aThe two numbers listed for each active ingredient apply to Iowa and Minnesota, respectively. SOURCE: Hallberg, G. R. 1987. Agricultural chemicals in ground water: Extent and implications. American Journal of Alternative Agriculture 2(1):3-15. age in production has declined to about 45 miDion acres (U.S. Department of Agriculture, 1986a). The growth of irrigation has been most dramatic in the western Great Plains. There, irrigation has increased the production of corn and sorghum, thus contributing to the growth of cattle feedIot opera- tions nearby. As large quantities of water are used for irrigation, however, some water tables decline and the cost of irrigation can rise. Inefficient irrigation practices have contributec! to aquifer depletion in some regions. On sandy soiTs, certain irrigation practices have contributed to the move- ment of pesticides and nitrate into groundwater. Irrigation has made agriculture possible in areas previously unsuitable for intensive crop production, such as the sandhilIs of Nebraska, parts of the central valley of CaTifornia, and much of the arid West. In certain regions of CaTifornia, irrigation is depleting aquifers at rates up to 1.5 million acre-feet per year. Land subsidence of up to 10 feet has resulted in some areas
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PROBLEMS IN U.S. AGRICULTURE TABLE 2-9 1980-1984 113 Acreage Irrigated in Areas With Declining Groundwater Supplies,a State Total Area Share (percent) of (acres, in 1,000s) Groundwater Total Area Irrigated Average Annual Irrigated With Decline Area From Declining Rate of Decline Groundwater (acres, in 1,OOOs~b Groundwater Aquifers (feet) - Ar~zona 938 606 65 2.03.0 Arkansas 2,337 425 18 0.51.3 California 4,265 2,069 48 0.53.5 Colorado 1,660 590 36 2.0 Florida 1,610 250 16 2.5 Idaho 1,450 225 15 1.05.0 Kansas 3,504 2,180 62 1.04.0 Nebraska 7,025 2,039 29 0.52.0 New Mexico 805 560 70 1.02.5 Oklahoma 645 523 81 1.02.5 Texas 6,685 4,565 73 1.04.0 Total 30,924 14,032 45 aIn the contiguous United States. bAreas with at least one-half foot average annual decline. SOURCE: U.S. Department of Agriculture. 1987. U.S. IrrigationExtent and Economic Importance. Agriculture Information Bulletin No. 523. Economic Research Service. Washington, D.C. because of withdrawals in excess of recharge. In other areas of California, the Groundwater table is rising, waterlogging soils and threatening agricul- tural production. In parts of the Great Plains, such as northern Texas and Oklahoma, where aquifer recharge is particularly slow, the OgalIala aquifer has been depleted to levels that restrict agricultural use. Between 1980 and 1984, Groundwater levels declined by 0.5 to 5.0 feet per year below 14 million acres of irrigated land (Table 2-9) (U.S. Department of Agriculture, 19870~. Total groundwater-irrigated acreage rose significantly in the 1970s and early 1980s. Center pivot irrigation alone increased from 3.4 million to 9.2 million acres between 1974 and 1983. Of the 30.9 million acres irrigated with groundwater, over 14 million acres, or 45 percent, are in areas where Groundwater is declining at least 1 foot per year (see Table 2-9~. California, Kansas, and Nebraska account for more than 2 million acres each of decTin- ing groundwater; Texas is responsible for more than 4 million acres. Much of this lane! produces crops already in surplus. More than 10 million acres of cotton, corn, grain sorghum, and small grains are produced with water from declining aquifers (Table 2-10~. More than 1.4 million acres of irrigated corn production in Nebraska are depleting Groundwater between 0.5 and 2.0 feet per year. Most irrigated acres receive high levels of fertilizers and other yield-enhancing inputs to boost yields. High yields secure high per acre federal farm program payments, which help pay for the cost of irrigation. In several areas in Nebraska that produce irrigated corn, pesti- cides and high levels of nitrate have been detected in groundwater. This
114 ALTERNATIVE AGRICULTURE TABLE 2-lO Irrigated Acreage of Surplus Crops in Areas of Groundwater Decline,a 1982 (in thousands) State Cotton Corn Grain Sorghum Small Grains Arizona 211 57 180 Arkansas 3 California 613 87 - 295 Colorado 315 56 73 Idaho 108 Kansas 664 542 683 Nebraska 1,456 123 44 New Mexico 72 55 96 126 Oklahoma 17 31 181 213 Texas 1,108 568 1,019 1,029 Total 2,024 3,176 2,074 2,751 NOTE: A dash indicates no irrigated crops. aIn the contiguous United States. SOURCE: U.S. Department of Agriculture. 1987. U.S. IrrigationExtent and Economic Importance. Agriculture Information Bulletin No. 523. Economic Research Service. Washington, D.C. contamination is prevalent in areas with sandy soils, which are highly porous. Irrigation in the arid West has been associated with mineralization and salinization of soils and water, as wed as groundwater depletion and surface and groundwater contamination. The Colorado River is perhaps the most striking example of depletion of water resources. The Colorado River is so intensively used for municipal water and agricultural irrigation that in very dry years there has been virtually no water left in the river as it crosses the Mexican border. The New River in the Imperial Valley is an example of surface water pollution from irrigated cropland. As municipalities and industry demand a greater share of available water in the West, agriculture will have to conserve. Conservation will require more prudent water use. It also may involve growing different crops and using production systems that retain more moisture in the soil. Agriculture currently uses 85 percent of available water in the West. The "use it or lose it" code of western water law encourages overuse of water based on fear of losing rights to use it in the future. With modest conservation, however, there is enough water to go around. If agriculture reduced water use through conservation by 15 percent, the amount of water available for municipal and industrial use in the region wouIcl double. Arizona's recent decision to place urban water needs ahead of agricultural use and to demand its share of the Colorado River's water is the most dramatic example of changing western water priorities. In the future, mar- ket forces and demand for western water win continue to alter use patterns, accelerating efforts and investments in conservation practices designed to increase the efficiency of agricultural water use.
PROBLEMS IN U.S. AGRICULTURE - 115 The buildup of salts on irrigated cropland can water. This method, however, moves salts severely reduce yields. This field of grain downstream and requires large volumes of shows heavy damage by salt. The principal water. Credit: Soil Conservation Service, U.S. method to reduce salinization of soils is to Department of Agriculture. flush salts out of soils by flooding fields with Soil Erosion Soil erosion remains a serious environmental problem in parts of the United States, even after 50 years of state and federal efforts to control it. Common management practices such as increased reliance on row crops grown continuously, fewer rotations involving forages, and larger farms being tilled by one operator have made it difficult to conserve soil resources in some areas. Similarly, some federal farm programs, particularly the com- modity price and income support programs, have historically encouraged high levels of production that work as a disincentive for effective erosion control practices. Soil erosion causes off-farm as well as on-farm damage. Quantifying the economic cost to society of offsite effects of erosion is difficult and estimates vary widely. Except for specific locations that have been studied intensively, it remains impossible to reach reliable judgments about the relative magni- tude of on- and off-farm costs associated with erosion. The USDA calculated annual offsite damage at between $2 billion and $S billion annually. Each year, the 350 to 400 minion acres of land used for agriculture are estimated to account for more than 50 percent of suspended sediments deposited in surface waters (U.S. Department of Agriculture, 1987a). Onsite erosion damage can reduce the productivity of land, labor, and capital on the farm, and increase the need for fertilizer and other inputs. About one-fifth of U.S. cropland is subject to serious damage from erosion (Clark et al., 1985; U.S. Department of Agriculture, 1987a). The impacts of onsite erosion have been
116 ALTERNATIVE AGRICULTURE Farm chemicals can reach dangerous levels in rivers that drain irrigated fields. Shown here is the New River leaving the heavily irrigated Imperial Valley and entering the Salton Sea in southern California. Credit: Richard Steven Street. estimated at between $1 billion and $18 billion per year, although the meth- odology to make such estimates is complex, controversial, and of limited value (National Research Council, 1986c; Pimentel, 1987; U.S. Department of Agriculture, 1987a). One part of the controversy involves what is being measured. For exam- ple, Crosson (1985) reported that about $0.5 billion is necessary to offset the annual Toss of soil nutrients by erosion; in contrast, Troeh et al. (1980) reported that a total of $18 billion in soil nutrients is lost annually from agriculture. Crosson estimated the nutrients directly available to crops each growing season; Troeh et al. estimated the value of aD nutrients lost, which included those directly available and those which would have been available after mineralization. There are many other aspects of the controversy on the impact of soil erosion on productivity. They include water runoff, water- holding capacity, organic matter, and soil depth (Pimentel, 1987~. It is generally recognized that soils with deep profiles are able to with- stand erosion without an appreciable drop in productivity. Thin soils over bedrock or other impermeable barriers are more vulnerable to erosion- - induced loss of productivity. Wind and water erode between 2.7 billion and
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PROBLEMS IN U.S. AGRICULTURE 119 pected to lose less than 2 percent of their productivity after 100 years. The USDA considers this loss insignificant because annual productivity gains from new technology and improved management are projected! to average at least 1 percent per year. Again, the methodologies available to project long-term consequences of erosion-induced productivity Tosses are crude ant! may not fully anticipate ways in which future technologies and eco- nomic conditions could interact with soil quality. For example, if fossil fuel prices increase, nitrogen fertilizer prices could rise because of higher prices for natural gas and energy needed in fertilizer production and distribution. The future value of uneroded soils may rise appreciably because of the capacity to sustain high levels of crop yields using rotations and leguminous cover crops. The use of conservation tiliage practices has increased since 1980. Nearly 100 million acres in 1987 were farmed using some form of conservation tiliage, compared with about 40 million in 1980. The main practice uses crop residue management to provide a partial mulch cover on the soil surface. This is accomplished through reduced tilIage, primarily chisel plowing, which can decrease erosion rates by up to 50 percent. The use of no tilIage, strip tilIage, and ridge tiliage, which can reduce erosion by 75 percent or more, accounts for only about 16 million acres (U.S. Department of Agriculture, 1987a). A large body of evidence indicates that intensive tiDage practices associ- ated with continuous monoculture or short rotations may make soils more susceptible to erosion. Reganold et al. (1987) recently reported this phenom- enon on two neighboring farms in the Palouse region of Washington state. The fields on one farm were worked for 38 years with conventional tillage and a shorter rotation. These fields had 6 inches less topsoil than an adja- cent farm where the fields were in longer rotations. Similar but fewer tilIage operations were used on the second farm. Water erosion research in the same area supports the conclusion that tiDage and fertilization practices associated with longer rotations, which often use legumes to supply nitro- gen, are less prone to erosion. Water erosion rates on similar fields of winter wheat were 13.1 tons per acre per year for fields not using leguminous meadows in the rotation compared to 2.4 tons per acre for fields that included them (Reganold et al., 1987~. Conventionally tilled soil with continuous intertiDed crops almost always experiences a decline in organic matter and some ability to retain moisture. AD other factors being equal, soils that historically receive nutrients in the form of manure or legumes tend to have higher levels of organic carbon and overall organic matter (Power, 1987~. Organic matter improves soil quality by increasing granulation, water infiltration, nutrient content, soil biota activity, and soil fertility and productivity. Management systems that reduce or eliminate synthetic fertilizer applications depend on increased microbial activity to make sufficient nutrients available to sustain crop yields (Doran et al., 1987~. Conventionally tilled fields without cover crops win likely have diminished organic content and be more susceptible to erosion and leaching of applied chemicals (Hoyt and Hargrove, 1986; Reganold et al., 1987~.
120 ALTERNATIVE AGRICULTURE Genetic Diversity U.S. agriculture produces a diverse array of crops and livestock. The genetic diversity of these crops has been substantially redistributed in re- cent years, however. A limited number of improved varieties of crops resis- tant to certain diseases and pests and responsive to fertilizers, management, and other inputs are now widely used. Increased genetic potential and improved cultural practices share about equal credit for past productivity gains. As a result, yield increases of 100 percent or more per acre have been recorded for most major commodities (Fehr, 19841. Vast areas are now planted with wheat, corn, and soybean varieties that are closely related and very uniform. Recent isozyme electrophoresis and zein chromatography analysis of 38 corn hybrids identified 49 as genetically unique; the remain- ing 39 fell into 6 categories that these techniques were unable to distinguish as different (Smith, 1988~. Concern for the genetic resources of domestic animals has been limited in spite of the decline in the populations of many breed populations and increasing uniformity within dominant breeds. The situation for dairy cattle is particularly acute. With the exception of Holsteins, most breed popula- tions are decreasing. This may eventually result in a decline in genetic variability within breeds. The Holstein breed is predominant; more than 90 percent of U.S. dairy cows are Holsteins (Niedermeier et al., 19831. Only 400 to 500 artificial insemination sires impregnate about 65 percent of the 6 million to 7 million dairy cows bred each year in the United States. And of the approximately 1,000 performance-tested dairy bulls used for artificial insemination in a given year, nearly half are the sons of the 10 best bulls of the previous generation (U.S. Office of Technology Assessment, 1987~. With practices lilce this, the genetic base will become narrower. A few major producers control the production of eggs and poultry. The genetic diversity of the breeding lines of chickens, which have undergone extensive selection for production in a controlled, high-input environment, is likely to be quite limped. A similar trend is beginning to emerge in the swine industry, with the development of specialized inbred lines raised under controlled conditions. There is a basis for concern regarding the loss of potentially important variation in these species. In the short term, genetically uniform plant and animal varieties can be resistant to certain pests and therefore be very productive. They can, ho~r- ever, be susceptible to other pests. The number of pests to which the variety or breed is susceptible can increase rapidly, resulting in vulnerability to devastating epidemics (National Research Council, 1972~. Genetic diversity within a crop variety provides some buffering against environmental ex- tremes, including pressures of diseases and insects. Likewise, planting several varieties of the same crop, which differ genetically for resistance to diseases, together or in different fields decreases the likelihood of Tosses due to a particular disease. This contributes to stability in yields and there- fore stability in income for a farmer. In the long term, unless genes are
PROBLEMS IN U.S. AGRICULTURE 121 preserved and maintained in germplasm banks or in the wild, crop and livestock species will suffer an irretrievable loss of genetic variability and, thus, reduce our ability to respond to specific stresses such as diseases (Duvick, 19361. The value of maintaining a diverse plant genetic resource base is illus- trated in the case of the use of classical plant breeding to control greenbugs in grain sorghum. The rapid increase in greenbugs caused an estimated $100 million loss to the U.S. sorghum crop in 1963. In the following year, about $50 million was expended for chemical insecticides on about ~ million acres. By 1976, however, resistance to the greenbug was found in a sorghum variety and incorporated into hybrids, which were grown on about 4 million acres. This example shows how common plant-breeding techniques, draw- ing on the genetic resource base for sorghum, could reduce chemical de- pendence, pest control costs, and pest damage. The subsequent emergence of a new biotype of greenbug illustrates an- other point. Biotype E of the greenbug emerged in 1980 and attacker! the previously resistant sorghum hybrids. Again, researchers have found an- other resistant variety of sorghum, which is now in general use by sorghum hybrid producers. Because insecticides to control greenbugs were not used for the length of time and in a manner that produced resistant greenbugs, the chemical could be used later when an emergency arose. Genetic resistance to pests in plants is widespread. The reservoir of plant genetic resources for biological pest control is an extremely valuable pest control component. There are many other examples (including wheat stem rust and European corn borer) where host plant resistance genes have continuously controlled a once-serious pest for several decades after a dev- astating crop loss. Effects of Pesticides One of the consequences of widespread genetic uniformity in crops and livestock is that when pests appear in epidemic numbers, they can have devastating effects on productivity. Existing pesticides are effective in con- trolling many serious threats to production and assuring unblemished products for market. They have helped maintain pest damage at between 5 and 30 percent of potential production in many cropping situations, including highly uniform and often continuous monocultures that would otherwise be highly susceptible to severe pest damage. However, the ad- verse effects of some pesticides are a serious problem in U.S. agriculture. Although the data are not conclusive, evidence suggests that pesticide use creates several immediate health hazards on the farm. There is growing evidence that pesticide use may pose serious health problems for farmers and farmworkers. A 1986 study by the National Cancer Institute found that Kansas farmworkers 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 nonfarm workers (Hoar et al., 1936~. Follow-up work in Ne- braska found that exposure to the herbicide (2,4-Dichlorophenoxy) acetic
122 ALTERNATIVE AGRICULTURE acid (2,4-D) more than 20 days per year increased the risk of developing NHL threefold (Hoar et al., 1988~. Other studies have suggested a link between pesticide use and increased incidence of NHL and multiple mye- loma among farmers (Pearce et al., 1985; Weisenburger, 1985~. In addition to the risk of developing cancer, pesticides also increase the incidence of acute illness. Acute exposure to pesticides may result in systematic or local disease. With systemic poisonings the clinical picture reflects the known toxicol- ogy of the compound and occurs shortly after exposure. Cholinergic illness due to cholinesterase inhibition from excessive organophosphate and carbamate exposure is the commonest type of systemic poisoning. Other less common, but equally life threatening examples of acute poi- sonings include the gastrointestinal, hepatic, renal, and pulmonary phases of paraquat poisoning, the metabolic stimulation that follows excessive exposure to the nitrophenol gTOUp of pesticides, . . . and the seizure disorders that herald the excessive chlorinated hydrocarbon ex- posures (Davies, 1985~. A number of recent studies have documented farmer applicator exposure to or~anonhosohate and carbamate insecticides through residues in urine ~~ ~~~ rat rat ~ . ~ it. . ~ .~ ~ A -__ _ Ad_ i_ ~ A_ I_ ~~ 1OQQ. and cholinesterase reduction American term Bureau reaerar~on, 'ma; McDonald, 1987~. Many farmworkers and their families, particularly mi- grant farmworkers, live and work in close and regular proximity to pesti- cides and are exposed to far greater amounts of these compounds than the average consumer. There is, however, no systematic monitoring of the health or exposure to pesticides of the more than 2 million farmworkers, applica- tors, harvesters, irrigators, and field hands who work around pesticides. Industrial workers who produce these pesticides receive the benefits of such monitoring. Widespread and heavy use of pesticides in this country has severely stressed some animals, including honeybee and wild bee populations (Brown, 1978~. Honeybees and wild bees are vital to the production of about $20 billion worth of fruits, vegetables, and forage crops. The large number of honeybees killed by pesticides resulted in the Bee Indemnity Act of 1970 to compensate apiarists for such Tosses. The act was repealed in 1980. But honeybees killed by pesticide use, loss of honey, and reduced crop yields account for at least $135 million in losses each year (Pimentel et al., 1980~. Because ecological interactions are extremely complicated and have gen- erally not been studied by the EPA, the effect of pesticides on the environ- ment is not well understood. The decline of predatory birds in the 1960s and 1970s because of chlorinated hydrocarbon pesticide use, however, is well documented, as is their recovery since the cancellation of these com- pounds. This recovery, however, is an anomaly. Although the ecological effects of pesticides are thought to be substantial, human health risks have traditionally been given priority. The EPA's special review of the insecticide carbofuran in October 1985 was the first time that an agricultural pesticide
PROBLEMS IN U.S. AGRICULTURE 123 Insecticides and fungicides are often applied result, there is a limited habitat for beneficial to tree crops using blasters. Here, herbicides insects. Erosion may also become a problem. also have been used and have killed all grass Credit: Agrichemical Age. and weed growth beneath the trees. As a had been so treated solely on the basis of its effects on wildlife. The EPA is currently reviewing a number of pesticides for ecological effects in conjunc- tion with human health effects, including the widely used ethylene bisdi- thiocarbamate (EBDC) group of fungicides and the insecticides dicofoT and diazinon. The EPA has canceled other pesticides, based partially on their effects on the ecology and wildlife. They include the insecticides DDT, endrin, and toxaphene. The EPA, the Department of the Interior, and states are currently in the process of implementing restrictions on more than 100 major pesticides to protect between 250 and 300 endangered plant and animal species on croplands, rangelands, and forestIands in more than 900 counties, pursuant to the Federal Endangered Species Act of 1973. When implemented, these restrictions could benefit plant and wildlife species remaining on or around these lands. Other unintended effects of pesticides include the resurgence of pests after treatment, occurrence of secondary pest outbreaks, and clevelopment of pesticide resistance in target pests. When insecticides or other pesticides are employed against one pest, its natural enemies or those of another pest may be reduced or eliminated. The control of insects by broad-spectrum insecticides also destroys beneficial insect populations. Populations of many previously innocuous species may then increase rapidly and cause major economic damage.
1Z4 ALTERNATIVE AGRICULTURE After heavy applications of pesticides over can cause severe damage in some crops, many years, Colorado potato beetles are now notably potatoes. Credit: Mycogen resistant to most registered insecticides and Corporation. In the early 1900s, for example, the major pests of cotton were the boll weevil and cotton leafworm (Nelson, 1962~. Since 1945 and the extensive use of toxaphene, DDT, methyl parathion, and other insecticides on cotton, the cotton bollworm, tobacco budworm, cotton aphid, and spider mite have become more serious pests than they were previously (National Research Council, 1975~. In particular, the cotton bollworm and tobacco budworm populations have grown because pesticides destroyed their natural enemies. In 197S, it was estimated that in; California 24 of the 25 top agricultural pests were secondary pests. The pesticides that wiped out their predators created or aggravated their role or dominance as pests (Van den Bosch, 1980~. More than 440 insect and mite species and more than 70 fungus species are now known to be resistant to some pesticides (National Research Coun- cil, 1986a). The committee expects that the problem will worsen. Pest pop- ulations already resistant to one or more pesticides generally develop resis- tance to other chemicals more rapidly, especially when the compounds work in the same way as previously used pesticides (National Research Council, 1986a). To counteract this, increased pesticide resistance in insect,
PROBLEMS IN U.S. AGRICULTURE 125 mite, and fungus populations, larger doses and more frequent applications of the previously used pesticides become necessary. It often becomes nec- essary to combine pesticides or substitute a different type of pesticide to achieve control. In some cases, more expensive, toxic, or ecologically haz- ardous pesticides have to be used. This starts a cycle of shifting resistance and increased use of pesticides. For these reasons, increasing levels of pesticide resistance in pest populations have significant environmental and economic costs. Pesticides can also cause crop losses. This can occur when the usual dosages of pesticides are applied improperly; when herbicides drift from a treated crop to nearby, susceptible crops; when herbicide residues prevent chemical-sensitive crops from being planted in rotation or inhibit the growth of subsequent crops; and when excessive residues of pesticides accumulate on crops, causing the harvested products to be destroyed or devalued in the marketplace. Beetles have seriously damaged potato plants toxic than routinely used insecticides protects in the foreground, despite insecticide the healthy plants. Credit: Mycogen treatments. A new biological insecticide that Corporation. controls the Colorado potato beetle and is less
126 ALTERNATIVE AGRICULTURE Food Safety Many of the chemical agents introduced into the food supply, including pesticides, fertilizers, plant-growth regulators, and antibiotics can be harm- fu] to humans at high doses or after prolonged exposure at lower doses. Although cancer-causing chemicals have attracted the most concern, agri- cultural chemicals can also have behavioral effects, alter immune system function, cause allergic reactions, and affect the body in other ways. Concern about the adverse effects of synthetic chemical pesticides on human and animal health began in the 1950s when it was discovered that organochIorine pesticides such as DDT are very persistent in the environ- ment and can damage animal systems. In the following years, the use of pesticides increased dramatically, largely because of their affordability, ef- fectiveness, ability to cut labor costs, and a variety of economic incentives for higher yields. Pest resistance also led to more applications per growing season. Increased use placed a growing burden on regulatory agencies to ensure the safety and proper use of the compounds, and set the stage for subsequent dietary exposure and environmental problems. The two major problems facing policymakers attempting to regulate pes- ticides are the lack of data on the health hazards of pesticides and a lack of accurate exposure data. A National Research Council (NRC) panel esti- mated that data to conduct a complete assessment of health effects were publicly available for only 10 percent of the ingredients in pesticide prod- ucts, mainly because of a lack of testing of older, widely used pesticides (National Research Council, 1984~. Pesticide producers and the EPA held more confidential data at that time, however. And since 1984, more data have been generated on the chronic health effects of these compounds. To date, insecticides accounting for 30 percent, herbicides accounting for 50 percent, and fungicides accounting for 90 percent of aB agricultural use have been found to cause tumors in laboratory animals (National Research Council, 1987~. There is still much scientific debate, however, over the extrapolation of the results of these studies to adverse effects in humans. Lack of accurate human exposure data further complicates the problem. A recent NRC report found little data on the actual levels of pesticides present in the human diet (National Research Council, 1987~. Although residue studies are being conducted, a complete picture of residue patterns in the food supply is still lacking. Based on available data, pesticide residues in the average diet do not make a major contribution to the overall risk of cancer for humans (National Research Council, 1982, 1987~. The risk, however, may not be insignificant and in most cases can be substantially reduced. Fungicides pose a particu- larly difficult chronic health problem. They account for more estimated oncogenic risk than herbicides and insecticides combined, but few effective alternatives are available or under development (National Research Council, 1987~. Further complications in risk assessment are that fungicides are often used in combinations, and residues of several oncogenic fungicides and other pesticides are commonly detected on the same crop.
PROBLEMS IN U.S. AGRICULTURE 127 Although little research has been done, there is evidence of synergistic interactions among pesticides and their contaminants with other com- pounds and with each other (DuBois, 1972; Knorr, 1975~. In 26 percent of 15 fruits and vegetables tested by the Florida Department of Agriculture, residues of two or more pesticides (including DDT, which was banned for agricultural use in 1972) were detected. This may understate actual residues, however, because the analytical method used cannot detect some com- pounds widely used on these crops. Although several pesticides are often present on a given food, pesticides continue to be regulated individually (Florida Department of Agriculture, 1988; Mott, 1984~. Organic fertilizers (manures and sewage sludge) and some inorganic fer- tilizers present health hazards if used inappropriately. These hazards in- clude increased nitrate levels in some foods and water, which pose a health problem when they are converted to nitrite through the action of bacteria and enzymes in the stomach. Nitrate can also be further metabolized during digestion to form nitrosamines, which are strongly carcinogenic. The poten- tial accumulation of nitrate in parts of some crops is generally greater when nitrogen is supplied in the synthetic chemical form because there is usually more nitrate available for uptake (Hodges and Scofield, 1983~. Nitrate percolation to groundwater and runoff from fields and feediots are major water contamination problems. Organic and inorganic fertilizers can cause these problems. Some sewage sludges, particularly those from industry, can contain high levels of heavy metals. These metals, which include cadmium, chromium, lead, and others, are toxic to most life forms and can accumulate in soil and in plant and animal tissues. The EPA has established guidelines for the agricultural application of sludges that con- tain heavy metals to avoid toxic accumulations in soil, forages, and vegeta- bles. Additionally, sludges that are not dried and/or completely composted can result in contamination of the soil with human pathogens (Maya, 1983; Poincelot, 1986; Vogtmann, 1978~. In addition, a wide variety of food-borne illnesses constitute a significant health problem in the United States. It is estimated that all types of food- borne illnesses are responsible for 33 million human illnesses and 9,000 human deaths in the United States each year (Young, 1987~. A significant percentage of these can be attributed to pathogenic bacteria of animal ori- gin. The bacterial pathogens listeria and saImonelIae, found in contami- natec! dairy products, and salmonelIae and campylobacter, found on some meat and poultry, have taken a significant disease toll in recent years. According to the Centers for Disease Control, bacteria from animal products account for approximately 53 percent of all outbreaks of food-borne illness for which a source was determined (Tauxe, 1986~. Antibiotics There has been scientific debate and concern about the subtherapeutic use of antibiotics in animal feed for nearly 20 years (Ahmed et al., 1984;
128 ALTERNATIVE AGRICULTURE Council for Agricultural Science and Technology, 1981; Jukes, 1973; Ken- nedy, 1977; National Research Council, 1980~. The focus of concern is the frequent development of antibiotic resistance in pathogenic bacteria as a consequence of antibiotic use in animals and in humans. Because many antibiotics used in animal feed are also used in human medicine, antibiotic- resistant pathogenic bacteria, particularly salmonellae, could develop and cause infections in animals and humans. The effectiveness of antibiotics for disease therapy would thus be diminished (Institute of Medicine, 1989; Murray, 1984~. Hirsch and Wigner (1978) demonstrated the transmission of resistant pathogens from animals to humans. This has been the subject of a thorough review (Feinman, 1984~. But there are still few studies that document the incidence of human disease caused by antibiotic-resistant pathogens of animal origin. Disease in humans due to antibiotic-resistant salmoneliae of animal origin is difficult to confirm and appears to be rare. Holmerg et al. (1984), however, demonstrated that antibiotic-resistant salmoneHae caused disease in humans who consumed meat from animals harboring saimonel- lae. In a study of 542 human cases of salmoneHosis in 1979, 28 percent of the bacteria isolated were resistant to at least 1 antibiotic. Resistance to 2 or more antibiotics was found in 12 percent of the salmoneliae strains (Tauxe, 1986~. In addition to an apparent increase in the incidence of salmoneHosis in humans, there are data to show that antibiotic resistance in the bacteria in animal intestinal microflora can be transmitted to humans because the same antibiotic-resistant bacteria are found in the human intestinal tract (Institute of Medicine, 1989~. This increases the concern that antibiotic resistance in animal pathogens might spread from animals to humans. The risk that this transmission poses to human populations is a matter of intense scientific debate. Meanwhile, antibiotic use continues to increase. A recent report by an Institute of Medicine (IOM) committee assessed human health risks resulting from the subtherapeutic use of penicillin and tetracyclines in animal feeds (Institute of Medicine, 1989~. Although the IOM committee recognized that there is little direct evidence implicating subtherapeutic use of antimicrobials as a potential human health hazard, the committee found substantial indirect or circumstantial evidence indicat- ing a potential human health risk from subtherapeutic use of antibiotics in animal feeds. This evidence includes the following: The use of antimicrobials in a variety of closes generates a strong selec- tive pressure for the emergence of drug-resistant bacteria. · Antimicrobial resistance among isolates of salmoneliae from farm ani- mals is prevalent because of extensive antimicrobial use on farms. · Animal and poultry carcasses in meat-processing plants are often found to be contaminated with intestinal pathogens resistant to antimicrobials. Human infections from salmoneliae or other enteric bacteria may follow handling and ingestion of improperly cooked meat or food products from animals contaminated with these organisms.
PROBLEMS IN U.S. AGRICULTURE 129 In assessing human health risk, the committee used a risk mode! that estimated the number of deaths from salmonellosis attributable to use of antimicrobials in animal feeds for prophylaxis and growth promotion and concluded that the likeliest estimate was in the range of 40 deaths per year (Institute of Medicine, 1989~. Further, it found that increased difficulty of treatment probably led to 20 additional deaths per year. The committee estimated that less than half of these deaths were from the use of antimicro- bials in growth promotion. It recognized, however, that the distinction between the use of these antimicrobials for growth promotion and prophy- laxis may not be great. The committee did not estimate incidences of mor- bidity because even fewer data were available. For the same reason, it did not estimate deaths due to other infectious organisms that cause food-borne illnesses and are known to develop resistance to the antimicrobials. The committee's conclusions suggested that reductions in subtherapeutic anti- biotic use would lessen the severity of human disease complications follow- ing infection with salmoneHae. Because data are limited, it is not possible to predict accurately the magnitude of public health gains that would result from a reduction of antimicrobial use in livestock agriculture. Human health concerns from antibiotic use go beyond bacterial resis- tance. Drug residues in food may also present risks. Many types of animal drugs are available to lay persons or farmers without the necessity of a veterinarian's prescription. Furthermore, it appears that even antibiotics limited to veterinary prescriptions are also widely available to lay persons (U.S. Congress, 1985~. An example of the inappropriate use of antibiotics is the use of chioramphenicol. Chioramphenico! was never approved for any use in food-producing animals; however, residues of chioramphenico! have been detected in animal food products (U.S. Congress, 1985~. The drug's sale in large containers, which was designed for the treatment of clogs, was banned by the U.S. Food and Drug Administration (FDA) in 1986 in an attempt to discourage the mixing of chioramphenicoT with animal feed (U.S. Food and Drug Administration, 1986~. ChIoramphenicol nonetheless con- tinues to be used in food-producing animals. Recent surveys of milk in New Jersey, New York, Oregon, and Pennsylvania found residues of chIoram- phenico! in 15 to 20 percent of the samples analyzed (Brady and Katz, 1988~. Its only FDA-approved use is for pet animals under veterinary care. University- and government-sponsored studies have found sulfametha- zine residues in meat and milk (Brady and Katz, 1988~. Sulfamethazine is available over the counter only in combination with other antibiotics, for use in swine and cattle. It is not aBowed for use in lactating dairy animals. Surveys of commercial milk, however, revealed that in certain parts of the country, greater than 50 percent of the samples had detectable sulfametha- zine residues. The human health hazard from these residues is not clear, although the compound may be carcinogenic in rodents (U.S. Food and Drug Administration, 1988~. Further, approximately 3 percent of the human population is allergic to sulfamethazine and many other antimicrobial drugs that may contaminate food products (Bigby et al., 1986~. The FDA surveillance programs for the detection of violative residues of
130 ALTERNATIVE AGRICULTURE ah veterinary antibiotics and chemicals are limited. Field investigations into tissue residue violations have revealed areas where the FDA may need to concentrate its enforcement activities. Dairy cows culled from herds had the highest rate of violative residues, followed by Bob veal calves (calves slaughtered at less than 4 weeks of age). In addition, 18 percent of the violative tissue residues in meat were from intramammary medication. Of these residues, 85 percent were derived from gentamicin, a drug not ap- proved by the FDA for intramammary use and legally available only through veterinarians (Paige and Kent, 1987~. These problems point out the need to improve the effectiveness of the FDA's regulation of animal drugs. SUMMARY Many economic and environmental factors have converges! in the l980s to make alternative farming practices more appealing. Exports have declined since 1981. Although the situation is improving, sectors of the agricultural economy continue to experience hardships. Despite the fact that net farm income has reached record levels, federal programs support an unprece- dented percentage of total net farm income. Nonpoint surface water pollution and contamination of groundwater by agricultural chemicals are recognized as environmental problems. Soil ero- sion remains serious in certain regions. In subhumid and arid regions, irrigation practices continue to deplete aquifers and cause salinization of agricultural land and water. Antibiotic and pesticide residues in food pre- sent risks that, while difficult to quantify and evaluate, can be reduced through alternate management systems. The ecological effects of certain pesticides are considered to be significant in some regions, although they remain largely unstudied. In response to these factors, some farmers are beginning to implement a range of alternative practices. The scientific bases for the major components of alternative agricultural systems are presented in Chapter 3. REFERENCES Agricultural Policy Working Group. 1988. Decoupling: A New Direction in Global Farm Policy. Washington, D.C.: Agricultural Policy Working Group. Ahmed, A. K., S. Chasis, and B. McBarnette. 1984. Petition of the Natural Resources Defense Council, Inc., to the Secretary of Health and Human Services requesting immediate suspension of approval of the subtherapeutic use of penicillin and tetracyclines in animal feeds. New York: Natural Resources Defense Council. American Farm Bureau Federation. 1988. Nine show pesticide exposure in health test. Mary- land Agriculture 19~4~:5. Bigby, M., S. lick, H. Jick, and K. Arndt. 1986. Drug-induced cutaneous reactions: A report from the Boston collaborative drug surveillance program on 15,438 consecutive inpatients, 1975 to 1982. Journal of the American Medical Association 256~24~:3358-3363. Brady, M. S., and S. E. Katz. 1988. Antibiotic/antimicrobial residues in milk. Journal of Food Protection 51~1~:8-11. Brown, A. W. A. 1978. Ecology of Pesticides. New York: Wiley.
PROBLEMS IN U.S. AGRICULTURE 131 Chesters, G., and L. l. Schierow. 1985. A primer on nonpoint pollution. Journal of Soil and Water Conservation 40:14-18. Clark, E. H., II, J. A. Haverkamp, and W. Chapman. 1985. Eroding Soils: The Off-Farm Impacts. Washington, D.C.: The Conservation Foundation. Council for Agricultural Science and Technology. 1981. Antibiotics in Animal Feeds. Report No. 88. Ames, Iowa: Council for Agricultural Science and Technology. Crosson, P. 1985. National Costs of Erosion on Productivity. Pp. 25~265 in Erosion and Soil Productivity: Proceedings of the National Symposium on Erosion and Soil Productivity. St. Joseph, Mich.: American Society of Agricultural Engineers. Davies, l. E. 1985. Health Effects of Global Pesticide Use. Miami, Fla.: World Resources Institute. Doran, J. W., D. G. Fraser, M. N. Culik, and W. C. Liebhardt. 1987. Influence of alternative and conventional agricultural management on soil microbial processes and nitrogen avail- ability. American Journal of Alternative Agriculture 2~3~:99-106. DuBois, K. D. 1972. Interaction of chemicals as a result of enzyme inhibition. Pp. 97-107 in Multiple Factors in the Causation of Environmentally Induced Disease, D. H. K. Lee and P. Kotin, eds. New York: Academic Press. Duvick, D. N. 1986. Plant breeding: Past achievements and expectations for the future. Economic Botany 40:289-297. Fehr, W. R., ed. 1984. Genetic Contributions to Yield Gains of Five Major Crop Plants. Special Publication No. 7. Madison, Wis.: Crop Science Society of America. Feinman, S. E. 1984. The transmission of antibiotic-resistant bacteria to people and animals. Pp. 151-171 in Zoonoses, Vol. I, I. H. Steele and G. W. Beran, eds. CRC Handbook Series. Boca Raton, Fla.: CRC Press. Florida Department of Agriculture. Residue Testing Laboratory. 1988. Data compiled from the 1986-1987 growing season, Florida Department of Agriculture, Tallahasse. Available from Environmental Health Research, Vero Beach, Fla. Glenn, S., and I. S. Angle. 1987. Atrazine and simazine to runoff from conventional and no- till corn watersheds. Pp. 273-280 in Agriculture Ecosystems and Environment. Amster- dam: Elsevier. Hallberg, G. R. 1987. Agricultural chemicals in groundwater: Extent and implications. Amer- ican Journal of Alternative Agriculture 2~1~:3-15. Hileman, B. 1988. The Great Lakes cleanup effort: Much progress, but persistent contami- nants remain a problem. Chemical and Engineering News, February 8, pp. 22-39. Hirsh, D. C., and N. Wigner. 1978. The effect of tetracycline upon the spread of bacterial resistance from calves to man. journal of Animal Science 46:1437. Hoar, S. K., A. Blair, F. F. Holmes, C. D. Boysen, R. l. Robel, R. Hoover, and J. F. Fraumeni, Jr. 1986. Agricultural herbicide use and risk of lymphomas and soft-tissue sarcoma. Journal of the American Medical Association 256~9~:1141-1147. Hoar, S. K., D. D. Weisenburger, P. A. Babbitt, R. C. Saal, K. P. Cantor, and A. Blair. 1988. A case-control study of non-Hodgkin's lymphoma and agricultural factors in eastern Ne- braska. American Journal of Epidemiology 128~4~: 901. Hodges, R. D., and A. M. Scofield. 1983. Effect of agricultural practice on the health of plants and animals produced: A review. Pp. 3-33 in Environmentally Sound Agriculture: Se- lected Papers from the Fourth International Conference of the International Federation of Organic Movements, W. Lockeretz, ed. New York: Praeger. Holmberg, S. D., M. T. Osterholm, K. A. Senger, and M. L. Cohen. 1984. Drug-resistant salmonella from animals fed antimicrobials. New England journal of Medicine 311:617-622. Hoyt, G. D., and W. H. Hargrove. 1986. Legume cover crops for improving crop and soil management in the southern United States. Horticultural Science 21:397-402. Institute of Medicine. 1989. Human Health Risks with the Subtherapeutic Use of Penicillin or Tetracyclines in Animal Feed. Washington, D.C.: National Academy Press. Jukes, T. 1973. Public health significance of feeding low levels of antibiotics to animals. Advanced Applications of Microbiology 16:1-30. Kahn, l. R., and W. M. Kemp. 1985. Economic losses associated with the degradation of an
132 ALTERNATIVE AGRICULTURE ecosystem: The case of submerged aquatic vegetation in Chesapeake Bay. Journal of Environmental Economic Management 12~3~:246-263. Kennedy, D. 1977. Antibiotics used in animal feeds. HEW News. Rockville, Md.: U.S. Food and Drug Administration. April 15. Knorr, D. 1975. Tin resorption, peroral toxicity and maximum admissable concentration in foods. LebensmittelWissenschaft Technologie 8:51-57. Maga, J. 1983. Organically grown foods. Pp. 305-350 in Sustainable Food Systems, D. Knorr, ed. Westport, Conn.: AVI Publishing Co. McDonald, D. 1987. Chemicals and your health: What's the risk? Farm Journal 3~2~:8-11. Mott, L. 1984. Pesticides in Food: What the Public Needs to Know. San Francisco: Natural Resources Defense Council, Inc. Murray, B. E. 1984. Emergence of diseases caused by bacteria resistant to antimicrobial agents. In Zoonoses, Vol. I, J. H. Steele and G. W. Beran, eds. CRC Handbook Series. Boca Raton, Fla.: CRC Press. Myers, C. F., J. Meek, S. Tuller, and A. Weinberg. 1985. Nonpoint sources of water pollution. Journal of Soil and Water Conservation 40:14-18. National Research Council. 1972. Genetic Vulnerability of Major Farm Crops. Washington, D.C.: National Academy Press. National Research Council. 1975. Cotton Pest Control. Washington, D.C.: National Academy Press. National Research Council. 1980. The Effects on Human Health of Subtherapeutic Use of Antimicrobials in Animal Feeds. Washington, D.C.: National Academy Press. National Research Council. 1982. Diet, Nutrition, and Cancer. Washington, D.C.: National Academy Press. National Research Council. 1984. Toxicity Testing: Strategies to Determine Need and Priori- ties. Washington, D.C.: National Academy Press. National Research Council. 1986a. Pesticide Resistance: Strategies and Tactics for Manage- ment. Washington, D.C.: National Academy Press. National Research Council. 1986b. Pesticides and Groundwater Quality: Issues and Problems in Four States. Washington, D.C.: National Academy Press. National Research Council. 1986c. Soil Conservation: Assessing the National Resources In- ventory, Vols. 1 and 2. Washington, D.C.: National Academy Press. National Research Council. 1987. Regulating Pesticides in Food: The Delaney Paradox. Wash- ington, D.C.: National Academy Press. Newsom, L. D. 1962. The boll weevil problem in relation to other cotton insects. Pp. 83-94 in Proceedings of the Boll Weevil Research Symposium. State College, Miss.: Mississippi State University. Niedermeier, R. P., l. W. Crowley, and E. C. Meyer. 1983. United States dairying: Changes and challenges. Journal of Animal Science 57(Suppl. 2~:44-57. Nielsen, E. G., and L. K. Lee. 1987. The Magnitude and Costs of Groundwater Contamina- tion from Agricultural Chemicals. Staff Report AGES87. Economic Research Service. U.S. Department of Agriculture. Washington, D.C. Paige, J. C., and R. Kent. 1987. Tissue residue briefs. FDA Veterinarian 2~6~:10-11. Pearce, N. E., A. H. Smith, and D. O. Fisher. 1985. Malignant lymphoma and multiple myeloma linked with agricultural occupations in a New Zealand cancer registry-based study. American lournal of Epidemiology 121~2~:225-237. Phipps, T. T., and P. R. Crosson. 1986. Agriculture and the environment: An overview. Pp. 3- 31 in Agriculture and the Environment: Annual Policy Review 1986, T. T. Phipps, P. R. Crosson, and K. A. Price, eds. Washington, D.C.: The National Center for Food and Agricultural Policy, Resources for the Future. Pimentel, D. 1987. Soil erosion effects on farm economics. Pp. 217-241 in Agricultural Soil Loss: Processes, Policies, and Prospects, l. M. Harlin and A. Hawkins, eds. Boulder, Colo.: Westview Press. Pimentel, D., D. Andow, R. Dyson-Hudson, D. Gallahan, S. lacobson, M. Irish, S. Kroop, A.
PROBLEMS IN U.S. AGRICULTURE 133 Moss, I. Schreiner, M. Shepard, T. Thompson, and B. Vinzant. 1980. Environmental and social costs of pesticides: A preliminary assessment. Oikos 34:127-140. Poincelot, R. 1986. Towards More Sustainable Agriculture. Westport, Conn.: AVI Publishing Co. Power, J. F. 1987. Legumes: Their potential role in agricultural production. American Journal of Alternative Agriculture 2~2~:69-73. Reganold, J. P., L. F. Elliott, and Y. L. Unger. 1987. Long-term effects of organic and conven- tional farming on soil erosion. Nature 330:370-372. Schneider, K. 1986. Erosion Is Called Small Threat to Crop Yields. The New York Times, 16 May 1986. Smith, l. S. C. 1988. Diversity of United States hybrid maize germplasm; Isozymic and chromatographic evidence. Crop Science 28:63-69. Smith, R. A., R. B. Alexander, and M. G. Wolman. 1987. Water-quality trends in the nation's rivers. Science 235:1607-1615. Tauxe, R. V. 1986. Antimicrobial resistance in human salmonellosis in the United States. Journal of Animal Science 62(Suppl. 3~:65-73. Troeh, F. R., l. A. Hobbs, and R. L. Donahue. 1980. Soil and Water Conservation for Produc- tivity and Environmental Protection. Englewood Cliffs, N.~.: Prentice-Hall. U.S. Congress, House. Committee on Government Operations. 1985. Human Food Safety and the Regulation of Animal Drugs. Union Calendar No. 274. Washington, D.C. U.S. Department of Agriculture. 1986a. Agricultural ResourcesCropland, Water, and Con- servationSituation and Outlook Report. AR-4. Economic Research Service. Washington, D.C. U.S. Department of Agriculture. 1986b. World AgricultureSituation and Outlook Report. WAS-45. Economic Research Service. Washington, D.C. U.S. Department of Agriculture. 1987a. Agricultural ResourcesCropland, Water, and Con- servationSituation and Outlook Report. AR-8. Economic Research Service. Washington, D.C. U.S. Department of Agriculture. 1987b. Agricultural ResourcesInputsSituation and Out- look Report. AR-5. Economic Research Service. Washington, D.C. U.S. Department of Agriculture. 1987c. Economic Indicators of the Farm Sector: National Financial Summary. 1986 ECIFS 6-2. Economic Research Service. Washington, D.C. U.S. Department of Agriculture. 1987d. U.S. Irrigation: Extent and Economic Importance. Agriculture Information Bulletin No. 523. Economic Research Service. Washington, D.C. U.S. Department of Agriculture. 1987e. World AgricultureSituation and Outlook Report. WAS-49. Economic Research Service. Washington, D.C. U.S. Department of Agriculture. 1988a. Agricultural Income and FinanceSituation and Outlook Report. AFO-31. Economic Research Service. Washington, D.C. U.S. Department of Agriculture. 1988b. Agricultural Outlook. Special Reprint: Agricultural Chemicals and the Environment. Economic Research Service. Washington, D.C. U.S. Department of Agriculture. 1988c. Agricultural ResourcesCropland, Water, and Con- servationSituation and Outlook Report. AR-12. Economic Research Service. Washing- ton, D.C. U.S. Department of Agriculture. 1988d. Financial Characteristics of U.S. Farms, lanuary 1, 1988. Economic Research Service. Washington, D.C. U.S. Department of Agriculture. 1988e. A National Program for Soil and Water Conservation: The 1988-97 Update. Washington, D.C. U.S. Department of Agriculture. 1988f. Outlook '88 Charts: 64th Annual Agricultural Outlook Conference. Economic Research Service. Washington, D.C. U.S. Environmental Protection Agency. 1984. Report to Congress: Nonpoint Source Pollution in the U.S. Washington, D.C. U.S. Environmental Protection Agency. 1987. Alachlor; Notice of Intent to Cancel Registra- tions; Conclusion of Special Review. Office of Pesticides and Toxic Substances. Washing- ton, D.C.
134 ALTERNATIVE AGRICULTURE U.S. Food and Drug Administration. 1986. Chloramphenicol Oral Solution; Withdrawal of Approval of NADA's. Federal Register 51~8~:1441. U.S. Food and Drug Administration. 1988. Proposed Removal of Regulation Regarding Sul- fonamide-Containing Drugs for Use in Food-Producing Animals. Federal Register 53(179):35,833-35,836. U.S. General Accounting Office. 1986a. Farm Finance: Financial Condition of American Ag- riculture as of December 31, 1985. Washington, D.C. U.S. General Accounting Office. 1986b. U.S. Agricultural Exports: Factors Affecting Compet- itiveness in World Markets. Washington, D.C. U.S. General Accounting Office. 1988. Farm Programs: An Overview of Price and Income Support, and Storage Programs. GAO/RCED-88-84BR. Washington, D.C. U.S. Office of Technology Assessment. 1987. Technologies to Maintain Biological Diversity. Washington, D.C.: U.S. Government Printing Office. Van Chantfort, E. 1987. Farm financial profile details improvement, diversity. Farmline 8(11):4-7. Van den Bosch, R. 1980. The Pesticide Conspiracy. Garden City, N.Y.: Anchor Books. Vogtmann, H. 1978. Ecologically sound preparation of farm yard manure and slurry. In Towards a Sustainable Agriculture, Proceedings of International Federation of Organic Agriculture Movements Conference, J. M. Besson and H. Vogtmann, eds. Switzerland: IFOAM. Weisenburger, D. D. 1985. Lymphoid malignancies in Nebraska: A hypothesis. The Nebraska Medical Journal 70(8):300-305. Williams, W. M., P. W. Holden, D. W. Parsons, and M. N. Lorber. 1988. Pesticides in Ground Water Data Base: 1988 Interim Report. Office of Pesticide Programs. U.S. Environmental Protection Agency. Washington, D.C. Wnuk, M., R. Kelley, G. Breuer, and L. Johnson. 1987. Pesticides in Water Supplies Using Surface Water Sources. Iowa City, Iowa: Iowa Department of Natural Resources and University Hygienic Laboratory. Young, F. E. 1987. Food safety and the FDA's action plan, phase II. Food Technology (Nov.):116-124.