Commercial fertilizers are applied to agricultural crops to increase crop yields. Prior to the 1950s, most farming occurred on small family farms with limited use of chemicals. The shift since then to larger corporate farms has coincided with the use of chemical fertilizers in modern agricultural practices. The three major types of commercial fertilizer used in the U.S. are nitrogen, phosphate, and potash.
Nitrogen (N) is found primarily in the organic form in soils, but can also occur as nitrate. Because nitrate is extremely soluble and mobile, it can lead to nuisance algal growth, mostly in downstream estuaries, and cause contamination of drinking water. Phosphorus (P) occurs in soil in several forms, both organic and inorganic. Phosphorus loss due to erosion is common and phosphate, while less soluble than nitrate, can easily be transported in runoff. Phosphorus/phosphate runoff can lead to nuisance algae and plant growth, often in freshwater streams, lakes, and estuaries. Potash is the oxide form of potassium (K) and its principal forms as fertilizer are potassium chloride, potassium sulfate, and potassium nitrate. When used at recommended application rates, there are few to no adverse effects from potassium, but it is a common component of mixed fertilizers used for high crop yields and is tracked in the fertilizer use surveys conducted.
This indicator shows use of the three major fertilizers in pounds per acre of land per year (expressed as N, P, or K) used for crop production from 1960 to 2006. Data are from an annual survey for agricultural crops conducted by the U.S. Department of Agriculture (USDA) National Agricultural Statistics Service (NASS) and from the Economic Research Service (ERS) Major Land Use series. Acreage used for crop production includes cropland harvested and crop failure as estimated in the ERS series. Cropland estimates as used in this indicator are a subset of agricultural land estimates discussed in the Land Cover and Land Use indicators. NASS also produces an annual Agricultural Chemical Usage report on four to five targeted field crops, based on data compiled from the Agricultural Resources Management Survey (ARMS). The ARMS surveys farmers in major agriculture-producing states that together account for a large percentage of crop acreage for corn, soybeans, cotton, and wheat. Results are presented for the years 2005-2006 by EPA Region.
What the Data Shows:
Based on fertilizer sales data, total use of the three major commercial fertilizers increased from 46.2 nutrient pounds per acre per year (lbs/acre/yr) in 1960 to 135.6 lbs/acre/yr in 2006, an increase of 194 percent (Exhibit 4-16). During this period, cropland used for crop production generally has fluctuated between 290 and 360 million acres with the largest changes occurring between 1969 (292 million acres) and 1981 (357 million acres) (Lubowski et al., 2006). Since 1996, cropland used for crop production has ranged between 314 and 328 million acres (Lubowski et al., 2006). Since 1996, aggregate commercial fertilizer use has fluctuated between 129 and 145 lbs/acre/yr with peak usage in 2004. Since 1960, nitrogen accounted for the steepest increase in use, from 17.0 lbs/acre/yr in 1960 to a peak of 81.6 lbs/acre/yr in 2004. Nitrogen currently accounts for about 57 percent of total fertilizer use, up from 37 percent in 1960. During the same period, phosphate and potash use grew more slowly; they remained steady between 25 and 36 lbs/acre/yr each since the late 1960s and now account for approximately 21 percent and 23 percent of total fertilizer usage, respectively.
The four major crops in the U.S.—corn, cotton, soybeans, and wheat—account for about 60 percent of the principal crop acreage and receive over 60 percent of the N, P, and K used in the U.S. Estimates from annual NASS Acreage reports show that from 1995 to 2006, between 76 and 80 million acres of corn were planted annually. In 2007, nearly 93 million acres were planted (USDA NASS, 2007a). A total of 76.5 million acres of corn were planted during the survey year (2005-2006). Corn acreage is concentrated in the center of the country (EPA Regions 5 and 7), but most EPA Regions grow some corn. Corn typically accounts for more than 40 percent of commercial fertilizer used (Daberkow and Huang, 2006).
The acreage of land planted in cotton was 12.4 million acres in the most recent ARMS survey year (2006) and has ranged between 11 and 16 million acres since 1990. Major cotton-producing states include 17 southern states located in EPA Regions 4, 6, and 9.
Production of winter, durum, and other spring wheat occurred on about 57 million acres in 2006 and is distributed across EPA Regions 5, 6, 7, 8, and 10. Wheat typically accounts for about 10 percent of all commercial fertilizer used (Daberkow and Huang, 2006).
Soybeans were the fastest-growing crop in total acreage, increasing from 57.8 million acres in 1990 to 75.5 million acres in 2006 (USDA NASS, 2007c). The majority of soybean acreage (80 percent) is concentrated in the upper Midwest in EPA Regions 5 and 7. Soybeans require the least fertilizer per acre of the four crops described here.
Overall, production of these four crops in the ARMS states used slightly more than 13.25 million tons per year (MT/yr) of fertilizer in 2005-2006 (Exhibit 4-17) of the 21.7 MT/yr estimated (2005-2006 average) by ERS for all crops produced in the entire U.S. Of this amount, slightly less than half (5.8 MT/yr) was applied in EPA Region 5 (Exhibit 4-17), most of which was used for corn. An additional 3.7 MT/yr was applied in EPA Region 7, primarily on corn or soybeans.
- USDA national estimates of fertilizer use are based on sales data provided by states, not actual fertilizer usage, and are susceptible to differing reporting procedures or accuracy from state to state.
- Data to identify cropland used for crop production are from the major land use series discussed in the Land Coverand Land Use indicators and do not include Alaska and Hawaii.
- Within the ARMS, not all states report fertilizer data every year for each crop type, making it difficult to establish year-to-year trends (a decrease in fertilizer use for a specific crop might be attributed to failure of a state to report, rather than an actual decrease of use).
- ARMS sampling is limited to program states, which represent 82 to 99 percent of crop acreage (across all surveyed crops) for the years 2005 and 2006, depending on crop type.
- The NASS Acreage report has estimates of acreage in production for the entire nation by crop, while fertilizer sales data are based only on USDA program states. Even though USDA program states represent the majority of U.S. planted acreage (often over 90 percent), the ability to generalize the data to the country as a whole is unknown, as non-program states, while representing a small percentage of a crop, might have much different application rates due to climate, weather, etc.
- Fertilizer applied to trees that are considered agricultural crops (e.g., nut-producing trees) is included in field crop summaries, but fertilizer applied in silviculture (e.g., southern pine plantations) is not covered by the NASS data collection system.
- Loading of nutrients in aquatic systems is not necessarily correlated directly with fertilizer use, but rather with the levels of fertilizer applied in excess of amounts used by crops, natural vegetation, and soil biota.
Daberkow, S., and W. Huang. 2006. Nutrient management. In: Wiebe, K., and N. Gollehon, eds. 2006. Agricultural resources and environmental indicators, 2006 edition. EIB-16. U.S. Department of Agriculture, Economic Research Service.http://www.ers.usda.gov/publications/arei/eib16/eib16_4-4.pdf
Lubowski, R.N., M. Vesterby, S. Bucholtz, A. Baez, and M.J. Roberts. 2006. Major uses of land in the United States, 2002. EIB-14. U.S. Department of Agriculture, Economic Research Service. http://www.ers.usda.gov/publications/eib14/
USDA Economic Research Service. 2007a. Data Sets: U.S. Fertilizer Use and Price.http://www.ers.usda.gov/Data/FertilizerUse/
USDA Economic Research Service. 2007b. Data Sets: Major Land Uses. http://www.ers.usda.gov/Data/MajorLandUses/
USDA NASS (United States Department of Agriculture, National Agricultural Statistics Service). 2007a. Acreage.http://usda.mannlib.cornell.edu/usda/nass/Acre/2000s/2007/Acre-06-29-2007.pdf
USDA NASS. 2007b. Agricultural chemical usage, 2006 field crops summary. May.http://usda.mannlib.cornell.edu/usda/nass/AgriChemUsFC/2000s/2007/AgriChemUsFC-05-16-2007_revision.pdf
USDA NASS. 2007c. Crop Production Historical Track Records.http://usda.mannlib.cornell.edu/usda/nass/htrcp//2000s/2007/htrcp-04-27-2007.pdf
USDA NASS. 2006a. Acreage. http://usda.mannlib.cornell.edu/usda/nass/Acre/2000s/2006/Acre-06-30-2006.pdf
USDA NASS. 2006b. Agricultural chemical usage, 2005 field crops summary. May.http://usda.mannlib.cornell.edu/usda/nass/AgriChemUsFC/2000s/2006/AgriChemUsFC-05-17-2006.pdf
USDA NASS. 2005a. Acreage. http://usda.mannlib.cornell.edu/usda/nass/Acre/2000s/2005/Acre-06-30-2005.pdf
USDA NASS. 2005b. Crop production: 2004 summary. Cr Pr 2-1 (05).http://jan.mannlib.cornell.edu/reports/nassr/field/pcp-bban/cropan05.pdf
USDA NASS. 2004. Acreage. http://usda.mannlib.cornell.edu/usda/nass/Acre/2000s/2004/Acre-06-30-2004.pdf
USDA NASS. 2001. Agricultural chemical usage, 2000 field crops summary.http://usda.mannlib.cornell.edu/reports/nassr/other/pcu-bb/agcs0501.pdf
|Fertilizer Applied for Agricultural Purposes|
|2.||ROE Question(s) This Indicator Helps to Answer|
|This indicator is used to help answer one ROE question: “What are the trends in chemicals used on the land and their effects on human health and the environment?(Chemicals to include toxic substances, pesticides, fertilizers, etc.)”|
|This indicator describes the use of the three major fertilizers (nitrogen [N], phosphorus [P], and potash [K]) in pounds per acre of land per year used for crop production from 1960 to 2006, based on annual fertilizer sales data and nationwide surveys. This information helps characterize changing fertilizer usage in the United States, which can impact aquatic ecosystems through runoff.|
|Exhibit 4-16Information on commercial fertilizer use in the U.S. is based on two sets of summary data from the United States Department of Agriculture’s (USDA’s) Economic Research Service (ERS): annual estimates of fertilizer use from 1960 through 2006, by nutrient, and annual estimates of the acreage of cultivated (harvested or failed) cropland from 1960 to 2006.
Information on fertilizer use for four common crops (corn, cotton, soybeans, and wheat) in major agriculture-producing state is based on fertilizer use data from USDA’s National Agricultural Statistics Service (NASS)Agricultural Chemical Usage reports, which report data collected by the Agricultural Resources Management Survey (ARMS).
|Exhibit 4-16This figure is based on two sets of summary data from USDA ERS. The full data set used in the indicator for annual estimates of fertilizer use from 1960 through 2006, by nutrient, is available from USDA ERS (2007a) (available athttp://www.ers.usda.gov/Data/FertilizerUse/). The acreage dataset, used to calculate fertilizer use per acre, is published in Lubowski et al. (2006) (available at USDA ERS, 2007b).
This figure is based on fertilizer use data from USDA’s Agricultural Chemical Usage reports (USDA NASS, 2006, 2007). The full set of data used in the indicator is available in the published documents (seehttp://usda.mannlib.cornell.edu/usda/nass/AgriChemUsFC//2000s/2006/AgriChemUsFC-05-17-2006.pdf (167 pp, 1.4MB, About PDF) andhttp://usda.mannlib.cornell.edu/usda/nass/AgriChemUsFC/2000s/2007/AgriChemUsFC-05-16-2007_revision.pdf (129 pp, 1.2MB) ). The complete underlying dataset can be requested from UDSA NASS (see http://www.ers.usda.gov/Data/ARMS/).
|Exhibit 4-16Overall commercial fertilizer use is based on annual sales data compiled by USDA’s ERS from several sources including ERS, TVA (Tennessee Valley Authority), AAPFCO (Association of American Plant Food Control Officials), and TFI (The Fertilizer Institute). Some limited descriptions of ERS data sources and approaches are provided in the source publication (Daberkow and Huang, 2006) and in USDA ERS (2003), but no details on statistical sampling procedures for calculating annual fertilizer sales are provided.
Basic information on procedures for surveying acreage can be found in Lubowski et al. (2006).
The ARMS survey is a multi-phase, multi-frame, stratified, probability-weighted sampling design. The target population for ARMS is the official USDA farm population in the 48 contiguous states. However, field-level data do not represent the total U.S. acreage of each crop surveyed, but generally represent over 90 percent of acreage and production of the target commodity. Specific commodities are covered on a rotating basis. For a full description, see http://www.ers.usda.gov/Data/ARMS/GlobalDocumentation.htm#doc.
|Exhibit 4-16To calculate nutrient pounds per acre of cropland, fertilizer sales data, in total tons of nutrients per year (for N, P, and K), were divided by nationwide crop acreage for the corresponding year from Table 6 (from the Summary Tables (USDA ERS, 2007b), not the tables in the main text) of Lubowski et al. (2006) (crop acreage being the sum of “cropland harvested” and “crop failure”).
Fertilizer use for four major crops, by nutrient, was calculated based on the crop-years and data sources as follows:
Data were aggregated by EPA Region.
|9.||Quality Assurance and Quality Control|
|Exhibit 4-16The ERS QA/QC methodology is described in USDA ERS (2003).
Trained enumerators conduct personal interviews, using questionnaires developed by NASS and ERS, with farm operators to collect data about their farm operations for the ARMS survey. An interviewer’s manual outlines detailed enumeration procedures for each phase of the survey. These documents provide specific directions on how the interview is to be conducted and insight into how to interpret each question. NASS provides enumerator training prior to the survey through a series of enumerator workshops. NASS Headquarters and ERS provide training materials to the State survey statisticians who conduct the training.
After questionnaires are completed by the enumerators, each questionnaire is reviewed by supervisory enumerators for completeness, inconsistent responses, or errors, and then transferred to a NASS State office. Supervisory statisticians also review each questionnaire before it is keyed into an electronic format. A computerized edit routine is then used to identify other potential errors or inconsistencies, checking that responses fall within expected ranges and that answers are consistent. When responses are anomalous, State survey statisticians investigate and either correct or verify the responses. A survey administration manual provides specific details about survey administration and data processing procedures.
|USDA does not publish specific thresholds or reference points beyond which fertilizer use is expected to affect people or ecosystems.|
|11.||Comparability Over Time and Space|
|Exhibit 4-16Specific information about the temporal and spatial comparability of data collected for fertilizer sales and for crop acreage each year is not available.
Within the ARMS, not all states report fertilizer data every year for each crop type, making it difficult to establish year-to-year trends (a decrease in fertilizer use for a specific crop might be attributed to failure of a state to report, rather than an actual decrease of use). As fertilizer application rates can vary from state to state, omission of Program States can result in significant differences in results, and the inability to accurately and confidently generalize results to the national level. ARMS sampling is limited to Program States, which represent 82 to 99 percent of crop acreage (across all surveyed crops) for the years 2005 and 2006, depending on crop type.
The NASS Acreage report has estimates of acreage in production for the entire nation by crop, while fertilizer sales data are based only on USDA Program States. Even though USDA Program States represent the majority of U.S. planted acreage (often over 90 percent), the ability to generalize the data to the country as a whole is unknown, as non-Program States, while representing a small percentage of a crop, might have much different application rates due to climate, weather, etc.
|12.||Sources of Uncertainty|
|Content under review.|
|13.||Sources of Variability|
|Exhibit 4-16Both fertilizer sales and acreage cultivated are subject to a variety of exogenous economic factors that may affect the data. Weather at certain times of the year can also affect fertilizer sales and acreage cultivated.
From USDA NASS (2007), p. 111: The [ARMS] surveys were designed so that the estimates are statistically representative of chemical use on the targeted crops in the Program States. The reliability of these survey results is affected by sampling variability and non-sampling errors.
Since all operations producing the crops of interest are not included in the sample, survey estimates are subject to sampling variability. The sampling variability expressed as a percent of the estimate is called the coefficient of variation (cv). Sampling variability of the estimates differed considerably by chemical and crop. Variability for estimates of percent of acres treated will be higher than the variability for estimates of application rates. This is because application rates have a narrower range of responses, which are recommended by the manufacturer of the product, and are generally followed. In general, the more often the chemical was applied, the smaller the sampling variability. For example, estimates of a commonly used active ingredient such as Glyphosate isopropylamine salt will exhibit less variability than a rarely used chemical. A commonly used active ingredient is defined as an active ingredient used on at least 40 percent of the acres planted for a crop at the Program State level. For these active ingredients, cv’s range from 1 percent to 10 percent at the Program State level and 1 percent to 52 percent at the individual state level. Active ingredients that are less frequently used have cv’s that range from 2 percent to 70 percent.
|No trend analysis has been conducted on the ERS data. The data from NASS represent only a snapshot in time, which makes it impossible to evaluate temporal trends.|
|This indicator includes the following limitations:
|Daberkow, S., and W. Huang. 2006. Nutrient management. In: Wiebe, K., and N. Gollehon, eds. Agricultural resources and environmental indicators, 2006 edition. EIB-16. U.S. Department of Agriculture, Economic Research Service. http://www.ers.usda.gov/publications/arei/eib16/eib16_4-4.pdf (7 pp, 530K).Lubowski, R.N., M. Vesterby, S. Bucholtz, A. Baez, and M.J. Roberts. 2006. Major uses of land in the United States, 2002. EIB-14. U.S. Department of Agriculture, Economic Research Service.http://www.ers.usda.gov/publications/eib14/.
USDA ERS (United States Department of Agriculture, Economic Research Service). 2007a. Data sets: U.S. fertilizer use and price. http://www.ers.usda.gov/Data/FertilizerUse/.
USDA ERS. 2007b. Data sets: Major land uses. http://www.ers.usda.gov/Data/MajorLandUses/.
USDA ERS. 2003. The Economic Research Service’s information quality guidelines.http://www.ers.usda.gov/AboutERS/QualityGuidelines3.pdf (17 pp, 93K).
USDA NASS (United States Department of Agriculture, National Agricultural Statistics Service). 2007. Agricultural chemical usage, 2006 field crop summary.http://usda.mannlib.cornell.edu/usda/nass/AgriChemUsFC/2000s/2007/AgriChemUsFC-05-16-2007_revision.pdf (129 pp, 1.2MB) .
USDA NASS. 2006. Agricultural chemical usage, 2005 field crop summary.http://usda.mannlib.cornell.edu/usda/nass/AgriChemUsFC//2000s/2006/AgriChemUsFC-05-17-2006.pdf (167 pp, 1.4MB) .
- Use the Toxics Release Inventory Explorer to find out about toxic and hazardous chemicals released from facilities in your community
- Contribute ideas and information during the permitting process of facilities that transport, store, or dispose of hazardous waste in your community
- Ask your grocer about organic foods and products
- If you grow your own vegetables or buy from a local community market, practice and support integrated pest management practices
- Consider ways to reduce or eliminate your use of fertilizers
- Fertilizer Applied for Agricultural Purposes
- Pesticide Residues in Food
- Reported Pesticide Incidents
- Toxic Chemicals in Production-Related Wastes Combusted for Energy Recovery, Released, Treated, or Recycled
Another opinion to consider:
I have not made my opinion yet. I still don’t have all the data that I need, but here is another viewpoint.
The Spraying of America
American agriculture dumps a billion pounds of pesticides on food, producing a truly toxic harvest.
by Christopher D. Cook
Earth Island Journal, Spring 2005
When Rachel Carson’s Silent Spring was published in 1962, the American pesticide business was in full postwar bloom. These “elixirs of death,” descended from World War II chemical warfare experiments, were suddenly ubiquitous – growing fivefold from 124 million pounds in 1947, to 637 million by 1960. Roughly 60 percent of these synthetic potions, some 376 million pounds, were applied on food. Toxic residues from pesticides were found everywhere: in water systems; in animals, including the “vast majority of human beings”; even in that most sacred nectar, mother’s milk. That now-infamous poison, DDT, was “so universally used that in most minds the product takes on the harmless aspect of the familiar.”
Fast-forward 40 years: President George W. Bush, campaigning for a second term, eases restrictions on pesticide use by farmers and homeowners. In a move cheered by agribusiness and pesticide producers, the Bush administration enables the Environmental Protection Agency – often criticized for issuing permissive pesticide standards to approve pesticides on its own, without consulting other federal agencies about effects on endangered species. Court-ordered “no-spray zones,” established along rivers to protect salmon and other fish, could soon be rolled back. Using toxins that may imperil life just got easier.
The food industry benefits from a decided hush when it comes to today’s silent spring. With concerns about genetically modified foods capturing the headlines – as well as the attentions of most food-industry critics today – the grave ecological effects of pesticides have been relegated to the back burner.
After decades of activism and success banning “dirty dozen” pesticides such as DDT and chlordane, we are told a cleaner future lies ahead. In the brave new high-tech world of bio-engineered crops, like the Monsanto potato that secretes its own pesticide, it seems we needn’t worry ourselves about poisoned farmworkers, pesticide drift, and children munching on toxic apples. Genetically modified crops are, according to USDA and corporate biotech officials, helping to cleanse the environment by reducing pesticides. As Bush’s agriculture secretary Ann Veneman told a UN Food and Agriculture Organization conference, biotechnology promises to ‘make agriculture more environmentally sustainable.”
The facts clearly refute the happy claims of Veneman and the politically connected GMO business: American industrial agriculture today dumps close to one billion pounds of pesticides on food crops, producing a truly toxic harvest.
Despite public assurances of a kinder, gentler agriculture, the biotech and pesticide businesses march hand-in-hand, two sides of the same corporate coin. The industry’s most prominent product, Monsanto’s “Roundup Ready” soybean, was designed to withstand intensive spraying, thus expanding sales of the firm’s highly popular – and highly toxic herbicide, Roundup. Since the 1996 introduction of Roundup Ready, the use of glyphosate, a key Roundup ingredient that studies have linked to non-Hodgkin’s lymphoma, has risen.
Roughly 85 percent of all cropland in America relies on herbicides – a business which will remain stable as long as agribusiness fights off new pesticide bans and maintains the myth that biotech is eliminating toxins in the fields.
Since the publication of Silent Spring, the amount of pesticides applied to our food has more than doubled. In 1997, according to industry figures, US growers poured more than 985 million pounds of pesticides onto their crops. The US accounts for more than one third of the $33.5 billion in global pesticide sales, the vast majority for farming. That’s an $11 billion business interest for the petrochemical and biotech industries to protect.
They’ve protected it well, perpetually – though not always successfully – fighting and delaying new regulations to limit toxins in the fields. After a modest decline in the 1980s, the amount of pesticides used each year has increased by more than 100 million pounds since 1991. At the same time, there’s been a dramatic increase in costs borne by farmers, whose spending on herbicides has more than doubled since 1980. Each year, over 100 million pounds of highly toxic active ingredients from pesticides are released into the environment in California alone.
In the world’s backyard
If it were merely a matter of waiting for Rachel Carson’s DDT ghosts of the 1960s to fade away, we might one day be in the clear. Rivers, lakes, fish, and birds might, over time, cleanse themselves of these toxins. But agriculture’s chemicals continue to flood our water and air with contamination. What is particularly startling is the degree to which pesticides have spread throughout the entire environment.
One might lament the plight of poisoned farmworkers or the effects of pesticides on farming communities and consign them to the realm of regrettable problems over which one has little control. While few would openly counsel reckless disregard for the health of farmworkers and their families who pay a very high price for our pesticide-based food system – it is all too easy to ignore and forget.
But according to a 1998 analysis by the California Public Interest Research Group, nearly four million Californians live within half a mile of heavy applications of pesticides, a third of which are “designated by state or federal regulatory agencies as carcinogens, reproductive toxins or acute nerve poisons.”
Spring, if not silent, is no doubt quieter. Every year agricultural pesticides alone kill an estimated 67 million birds. An array of disturbing side effects is in store for those lucky enough to survive a sublethal dose, including ‘increased susceptibility to predation, decreased disease resistance, lack of interest in mating and defending territory, and abandonment of nestlings,” according to a 1999 report by Californians for Pesticide Reform and the Pesticide Action Network.
A key indicator of today’s pesticide pollution epidemic lies underground, in the hidden waters that ultimately percolate up into rivers, lakes, and wells. Groundwater is the source of 50 percent of America’s drinking water, and it is intimately interconnected with surface water.
Since the late 1970s, studies have found more than 139 different pesticide residues in groundwater in the US, most frequently in corn- and soybean-growing regions. One study of a Nebraska aquifer found numerous pesticides at “lifetime health advisory” levels. All of the samples contained atrazine, the most commonly-used pesticide applied to America’s cornfields. In Iowa, toxic chemicals are found in roughly half of the groundwater.
Even closer to home were the findings of a 1992 national pesticide survey by the EPA, which discovered that ten percent of community wells “contained detectable levels of one or more pesticides.” Well water samples gathered by the California Department of Pesticide Regulation show residues of 16 active ingredients and breakdown products from agricultural pesticides.
Groundwater pesticide presence, though, pales in comparison with the chemicals’ prevalence in surface rivers and streams. In California, state regulators detected pesticides in 95 of 100 locations in the Central Valley. More than half of these sites exceeded safe levels for aquatic life and drinking water consumption. In Kentucky, where farmers annually apply roughly 4.5 million pounds of the top five herbicides, these chemicals showed up routinely in rivers. A two-year study by the state Department of Environmental Protection discovered atrazine and metolachior, both used heavily on corn, in a full 100 percent of the 26 river sites they examined; another chemical, simazine, was found 91 percent of the time.
The spread of these toxins is a serious matter affecting both environmental and public health. Atrazine, found widely in drinking water across the Midwest and detectable on many foods, is a “possible human carcinogen,” according to the EPA. Studies suggest it may cause ovarian cancer.
Nationwide reports are equally troubling and reveal a bath of chemicals harmful to fish and the broader freshwater ecosystem. In a ten-year study examining thousands of streams across the country, the US Geological Survey traced the proliferation of numerous agricultural pesticides: atrazine was in 90 percent of the streams; deethylatrazine and metolachlor were in 82 percent of all samples; others were detected at least 40 percent of the time. Still more disquieting was a 1999 USGS finding of an average of 20 pesticides, mostly agricultural, at each river or stream tested. Chemical concentrations of some compounds were frequently found to exceed allowable levels in drinking water, and one or more standards for protecting aquatic life were exceeded in 39 of 58 sites.
In studies conducted over the past 30 years, nearly half of all pesticides targeted for research were found in stream sediment, and some 64 percent in edible fish, mollusks, and other aquatic life.
More and more, scientists are observing important changes in hormones and reproductive systems among fish and other waterborne creatures exposed to pesticides One study of sex hormones in carp revealed that the ratio of estrogen to testosterone in both males and females was “lower at sites with more pesticides.”
Pesticides may also be a factor behind rising numbers of frog deformities, such as extra or missing limbs. In a 2002 study published in the Proceedings of the National Academy of Sciences, biologist Joseph Kiesecker compared frogs in several Pennsylvania ponds, with and without pesticide runoff. The rate of misshapen frogs was nearly four times higher in the ponds with pesticides.
Environmentalists and scientists are not the only ones complaining. Fishing enthusiasts are angry about the poisoning of their prey. Randy Fry of the Recreational Fishing Alliance of Northern California has written that pesticide pollution “seriously impacts the estuary’s food-web and thereby limits the productivity of Central Valley populations of salmon, steelhead, striped bass, and sturgeon while increasing the pollutants carried by these fish.” Fry has noted declines in fisheries throughout the Valley.
Something in the air
Perhaps the greatest – yet most elusive measure of pesticides’ long reach is their presence in the air we breathe. “Nearly every pesticide that has been investigated has been detected in air, rain, snow, or fog across the nation at different times of year,” says the US Geological Survey. Given just a lazy breeze, toxins can migrate for miles. A seemingly innocuous spraying or fumigation of a rural farm field can let pesticides drift through air currents for
hours, even days, ending up as residue in nearby towns, ruining organic crops downwind and further polluting waterways. Diazinon, a highly volatile agent sprayed widely on nuts and stone fruit, actually increases its drift concentrations as time passes, the greatest amount of drift showing up two to three days after spraying. Although levels generally diminish, pesticide drift can last for weeks, and sometimes months after application.
The epicenter for the pesticide drift problem, particularly its human effects, is California, where decades of suburban sprawl – and intensely consolidated agriculture – have wedged burgeoning population centers up against farms. Blending agriculture with suburbs would seem a fine rural-urban complement but for the rampant use and drift of pesticides, which are exceedingly toxic, even at low levels, for children. “Pesticides in air are often invisible and odorless, but like second-hand cigarette smoke, inhaling even small amounts over time can lead to serious health problems, especially for children,” reports Susan Kegley, staff scientist for the Pesticide Action Network.
More than 90 percent of pesticides used in California (including non-agricultural pesticides) are likely to drift, and roughly a third of those are highly toxic to humans, according to a 2003 study by Californians for Pesticide Reform. Samples of two pesticides, chiorpyrifos and metam sodium, taken near sprayed fields, produced residues that were, respectively, some 184 and 111 times the acute exposure standards set by government for a one-year-old child.
The Gulf of Toxins
The Gulf of Mexico is afflicted with a “dead zone” stretching across several thousand square miles along the Louisiana-Texas coast. A massive algae bloom feasts on a steady diet of nitrogen and other nutrients flowing downstream from the Mississippi River. In summer, when the river’s flow peaks, the bloom spreads and chokes the Gulf’s northern coasts, cutting off oxygen that supports sea life. In 1999 the zone ballooned to nearly 12,500 square miles – the size of New Jersey. The depleted water near the bottom of the Gulf contains less than two parts per million of dissolved oxygen, not enough to sustain fish or bottom-dwelling life.
One of the chief contributors to this dead zone is American agriculture and its countless tributaries of petroleum-based fertilizers, pesticides, and animal feces overflowing from giant factory farms. The Mississippi River Basin, which drains an area representing about 41 percent of the contiguous US,
is home to the majority of the nation’s agricultural chemicals. About seven million metric tons of nitrogen in commercial fertilizers are applied in the Basin each year, and the annual load of nitrates poured from the Mississippi River into the Gulf has tripled since the late 1950s, when pesticides and synthetic fertilizers began to dominate the agricultural scene. Another key ingredient is on the rise: billions of tons of factory-farm animal waste, overloaded with nitrogen and other potentially damaging nutrients.
In 1999, when Congress, the EPA and environmental groups pressed for cuts in farm pollution to clean up the Gulf of Mexico, some agricultural trade groups raised the specter of farm closures and diminished food production. ‘Crop yields in the Midwest could shrink if federal regulators try to reduce use of fertilizers to cut pollution in the Mississippi River and in the Gulf of Mexico,” the Associated Press reported, summing up the agribusiness argument. Asking farmers to reduce fertilizers would be “basically asking them to go out of business,” said Cliff Snyder, representing the Potash and Phosphate Institute. “It would have a significant economic impact if producers were required to reduce nutrient input.., at a time when the farm economy is dismal.”
Despite the economic trap, some forward-looking farmers are contemplating ways to either use less synthetic fertilizer, which itself is quite costly, or at least drain their fields away from rivers, perhaps into wetlands that could use the nitrogen.
Beyond the Gulf case, chemical fertilizers – laden with nitrogen, ammonia, and phosphorus, as well as trace toxic metals like cadmium – are a serious environmental problem.
Overshadowed in the public mind by pesticides, synthetic chemical fertilizers severely deplete and erode soil and drain toxic nutrients into the water supply. They have become a perilous crutch – with over 14 million tons applied annually, seven tons per square mile in the upper Midwest – injecting excessive nutrients into the ground, and ironically, robbing soil of its fertility. A 1984 World Bank report concluded that American agriculture’s growing reliance on synthetic fertilizers “has allowed farmers to abandon practices – such as crop rotation and the incorporation of plant and animal wastes into the soil – which had previously maintained soil fertility.”
The petrochemical addiction
Why has pesticide use increased even in this time of growing ecological awareness? In Living Downstream, scientist-author Sandra Steingraber describes the political economy that has driven agriculture into a self-feeding cycle of poison. First, the arrival of synthetic pesticides following World War II reduced labor on the farm. Simultaneously, profits per acre began to shrivel. “Both these changes pressed farmers into managing more acres to earn a living for their families.” Bigger farms, and federal subsidies promoting mono-crop agriculture, “further increased the need for chemicals to control pests. And the use of these chemicals themselves set the stage for additional ecological changes that only more chemicals could offset.”
The decline of crop rotation in favor of monocropping – the planting of the same crop year after year – enables insects to adapt and recover, continuing the upward chemical spiral. Through Darwinian natural selection, the strongest few insects able to resist insecticides “become the progenitors of the next generation as their more chemically sensitive compatriots are killed off,” explains Steingraber. Thus pesticides ultimately create insects that are less susceptible to them. During the postwar pesticide revolution between 1950 and 1990, the number of insect species resistant to pesticides mushroomed from fewer than 20 to more than 500. In roughly the same period, the amount of crops lost due to insect damage doubled.
It doesn’t have to be this way. Agriculture can be prolific and efficient without pesticides. The miraculous march of American agriculture toward unparalleled productivity long before the postwar pesticide revolution is a compelling testimonial to the possibilities of organic farming. Before agribusiness’ petrochemical addiction, farmers used crop rotation and diversified agriculture to replenish soils and keep pests on the run. Crop diversity supplied sustenance for farm families and livestock and a natural insurance policy against pest outbreaks or weather disasters.
While many so-called conventional” growers have bravely made the transition into organics – itself a lengthy and costly process for which there is virtually no government support the wider food economy and the profits of agribusiness rely on farmers’ continued deployment of chemical warfare in the fields. The near-perennial , American surplus fueled by petrochemicals keeps farm crops cheap, l-,4′ not so much for consumers as for the f intermediary complex of food processors, fast-food chains, and supermarkets. Back in the days of Silent Spring, o the US had for years been stockpiling food, requiring ever-larger subsidy payments and growing pressures on exports and food aid.
As Carson remarked then, “We are told that the enormous and expanding use of pesticides is necessary to maintain farm production.” Yet, she said – noting that American taxpayers were paying more than $1 billion a year for this surplus food storage – “Is our real problem not one of over-production?” Excess supply is primarily a problem for farmers, both here and abroad, who are forced by price-depressing surpluses to “get big or get out.” For the petrochemical industry and its close partner, the biotech business, today’s economy of surplus production and exports, and of a mono-crop industrial agriculture stripped of its natural sustainability, is not a problem at all. Except that they, too – and their children – must inhabit a poisoned world. *
Christopher D. Cook is an award-winning investigative journalist who writes for Mother Jones, Harper’s, The Nation, and elsewhere. He is author of Diet for a Dead Planet: How the Food Industry Is Killing Us, published November 2004 by the New Press. This article was adapted from the book. (For more information, visit dietforadeadplanet. com.)
as I try to broaden my own information base
And another opinion:
I still haven’t formed my opinion yet.
Energy Use in Agriculture: Background and Issues
Agriculture requires energy as an important input to production.
Agriculture uses energy directly as fuel or electricity to operate machinery and equipment, to heat or cool buildings, and for lighting on the farm, and indirectly in the fertilizers and chemicals produced off the farm.
In 2002, the U.S. agricultural sector used an estimated 1.7 quadrillion Btu of energy from both direct (1.1 quadrillion Btu) and indirect (0.6 quadrillion Btu) sources. However, agriculture’s total use of energy is low relative to other U.S. producing sectors. In 2002, agriculture’s share of total U.S. direct energy consumption was about 1%. Agriculture’s shares of nitrogen and pesticide use — two of the major indirect agricultural uses identified by the U.S. Dept of Agriculture (USDA) — are signficantly higher at about 56% and 67%, respectively.
U.S. farm production — whether for crop or animal products — has become increasingly mechanized and requires timely energy supplies at particular stages of the production cycle to achieve optimum yields.
Energy’s share of agricultural production expenses varies widely by activity, production practice, and locality.
Since the late 1970s, total agricultural use of energy has fallen by about 28%, as a result of efficiency gains related to improved machinery, equipment, and production practices.
Despite these efficiency gains, total energy costs of $28.8 billion in 2003 represented 14.4% (5.2% direct and 9.3% indirect) of annual production expenses of $198.9 billion.
As a result, unexpected changes in energy prices or availability can substantially alter farm net revenues, particularly for major field crop production.
High fuel and fertilizer prices in 2004, and increasing energy import dependence for petroleum fuels and nitrogen fertilizers has led to concerns about the impact this would have on agriculture.
High natural gas prices have already contributed to a substantial reduction in U.S. nitrogen fertilizer production capacity — over a 23% decline from 1998 through 2003. In the short run, price- or supply-related disruptions to agriculture’s energy supplies could result in unanticipated shifts in the production of major crop and livestock products, with subsequent effects on farm incomes and rural economies.
In the long run, a sustained rise in energy prices may have serious consequences on energy-intensive industries like agriculture by reducing profitability and driving resources away from the sector.
This report provides information relevant to the U.S. agricultural sector on energy use, emerging issues, and related legislation. It will be updated as events warrant.
Energy Use in Agriculture:
Background and Issues
Agriculture, as a production-oriented sector, requires energy as an important input to production.
U.S. farm production — whether for crop or animal products — has become increasingly mechanized and requires timely energy supplies at particular stages of the production cycle to achieve optimum yields.
Several key points that emerge from this report are:
- agriculture is reliant on the timely availability of energy, but has been reducing its overall rate of energy consumption;
- U.S. agriculture consumes energy both directly as fuel or electricity to power farm activities, and indirectly in the fertilizers and chemicals produced off farm;
- energy’s share of agricultural production expenses varies widely by activity, production practice, and locality;
- at the farm level, direct energy costs are a significant, albeit relatively small component of total production expenses in most activities and production processes;
- when combined with indirect energy expenses, total energy costs can play a much larger role in farm net revenues, particularly for major field crop production; and
- energy price changes have implications for agricultural choices of crop and activity mix, and cultivation methods, as well as irrigation and post-harvest strategies.
This report provides background on the relationship between energy and agriculture in the United States.
The first section provides background information on current and historical energy use in the U.S. agricultural sector and how this fits into the national energy-use picture. Energy’s role in agriculture’s overall cost structure is detailed both for present circumstances and for changes over time.
Finally, this section examines how agriculture’s energy-use pattern varies across activities and regions.
Agriculture as a Share of U.S. Energy Use:
Direct Energy Use.
In 2002, the U.S. agricultural sector (encompassing both crops and livestock production) used an estimated 1.1 quadrillion Btu3 of total direct energy.4 This represents slightly more than 1% of total U.S. energy consumption of 98 quadrillion Btu in 2002. (See Figure 1.) In comparison, the non-agricultural component of the industrial sector is estimated to have used 31.4 quadrillion Btu (32%), while the transportation sector used 26.5 quadrillion Btu (27%).
As a result of its small share, significant changes in direct energy consumption by the U.S. agricultural sector are unlikely to have major implications for the overall supply and demand for energy in the United States.
However, within the agricultural sector, changes in the supply and demand of energy can have significant implications for the profitability of U.S. agriculture as well as the mix of output and management practices.
Indirect Energy Use.
In contrast to direct energy, agriculture’s share of two important indirect energy uses — fertilizer and pesticide use — is signficantly higher.
According to the Government Accountability Office (GAO),5 in 2002 agriculture accounted for about 56% (12 million out of about 21.4 million metric tons) of total U.S. nitrogen use.6
Nitrogen fertilizer is the principal fertilizer used by the U.S. agricultural sector. (See the section “Fertilizer Production Costs” later in this report for more information.) Data on agriculture’s share of phosphorous and potash fertilizer use was not readily available.
In addition, the U.S. Environmental Protection Agency (EPA) estimates that U.S. agriculture accounted for 67% of expenditures on pesticides in the United States in 2001 (the year for which data was most recently available).7
Composition of Energy Use Has Shifted Over Time.
Gasoline’s relative share as a source of farm energy has declined substantially over the past four decades, falling from a 41% share in 1965 to about a 9% share in 2002. (See Figure 4.)
The direct use of natural gas and LP gas also experienced a decline in share, falling from a combined 15% to 8%.
In contrast, diesel fuel and electricity both gained substantially, rising from 13% and 6% shares respectively in 1965 to 27% and 21% shares in 2002.
The shift away from gasoline-powered machinery toward diesel-powered machinery underlies the rise of diesel and decline of gasoline. Diesel is better performing than gasoline in terms of miles per gallon and miles per Btu. Diesel fuel also tends to be significantly cheaper on a gasoline-equivalent basis.11 The overall decline in total direct energy use also reflects an important decline in the stock of agricultural machinery, equipment, and motor vehicles that has occurred since total farm machinery inventories peaked in 1979.12
Capital depreciation exceeded capital expenditure in every year from 1980 through the mid-1990s.
The capital depletion was due to several factors including,
- first, increased machine efficiency and,
- second, shifts away from conventional tillage practices (which required working the soil many times prior to planting) toward reduced and no-till practices (which require fewer passes over the soil and, therefore, less fuel consumption).
- In addition, conservation tillage practices have helped to conserve soil moisture and nutrients (lowering the need for commercial fertilizers) and to prolong the useful life of tractors and equipment.
Since 1965 fertilizer and pesticide use have exhibited a disjointed pattern as a share of energy source for U.S. agriculture, rising from a combined 25% share in 1965 to slightly above a 46% share in 1986, then declining to a 35% share by 2002.
- Increasing use of precision farming
- i.e., computerized equipment that allows precise quantity
- and placement of inputs such as fertilizers and pesticides,
- conservation tillage, and
- crop residue management have all contributed to lower fertilizer volumes without sacrificing yield gains.13
Plantings of genetically engineered crops such as Bt corn and Bt cotton, which require fewer pesticide applications, also have contributed to a reduced pesticide volume.
In addition, improved pesticide products and expanded use of crop scouting services have contributed to lower pesticide volumes while maintaining or improving the level of pest control.
Efficiency Gains in Farm Energy Use.
The large declines in agricultural sector use of direct and indirect energy sources since the late 1970s has not come at the expense of lower output. Agriculture appears to have made dramatic efficiency gains in energy use. The gains are measured by sharply declining energy-use per unit of output indices for both direct and indirect energy categories.
Since 1980, direct energy use (DEU) per unit of output has fallen almost continuously while total agricultural sector output has risen steadily (see Figure 5).
Indirect energy use (IEU) per unit of output has also tracked downward, but with more variability than direct energy use (see Figure 6). Both direct and indirect energy use per unit of output appear to have plateaued somewhat in the 1990s.
Energy’s Share of Agricultural Production Costs
Producers are slowly gaining more options for responding to energy price changes, but in the short term most energy price increases still translate into lower farm income. During the 2000-2003 period, U.S. farmers spent an annual average of nearly $194 billion on total production expenses (see Table 2).
Of this total, nearly 15%, or an estimated $28.8 billion, was for energy expenses. Energy’s share of annual farm production expenses varies from year to year with changes in planted acres, the crop and livestock mix, and relative energy prices.
Direct Energy Costs.
Demand for refined petroleum products such as diesel fuel, gasoline, and LP gas in agricultural production is determined mainly by the number of acres planted and harvested, weather conditions, and the prices for the various types of energy. Because the majority of energy used in the United States (and the world) is derived from either petroleum-based sources — such as gasoline, diesel, and LP gas — or natural gas, their prices tend to move together. This limits the success of switching among fuel sources to reduce energy costs.
During the 1960s and 1970s, direct energy costs (for inputs such as petroleum products and electricity) varied substantially as a share of total farm costs, ranging from 4% to 8% (see Figure 7). However, since the mid-1990s direct energy’s share of total farm costs has averaged about 5%.
Electricity’s share of production costs grew from about 0.7% in the mid-1970s to 1.9% by 1989, and has held fairly steady ever since as technological efficiency gains in electricity use have essentially offset price rises (see Figure 8).
In contrast, fuel costs have declined as a share of production costs, falling from a 6.4% share in 1981 to average 3.3% since 1994, due in large part to efficiency improvements in farm machinery, as well as adoption of no- or minimum-tillage cultivation practices. 14
[USDA, Economic Research Service, Agricultural Outlook, AO-1, June 1975, p. 9.]
Indirect Energy Costs.
Indirect energy costs (for fertilizers and pesticides) have shown considerable variability over the past 40 years, ranging between 8% and 12% of total farm production expenses.
The most notable cost-share movement occurred in 1974, when indirect energy costs experienced a sharp upward spike due to a jump in fertilizer prices.
In 1971, USDA’s Economic Stabilization Program had frozen U.S. fertilizer prices at the producer level.14 These price controls were removed on October 25, 1973, and resulted in a rapid rise in U.S. fertilizer prices and expenditures.
Since 1996, indirect energy’s share of total farm costs has trended downward to about a 9% share in 2003.15
Agricultural Chemical Costs.
Pesticides comprise the majority of agricultural chemical expenditures. Pesticides are commonly broken out into three major types —
- insecticides, and
- Defoliants, used primarily by cotton in the United States, are another major agricultural chemical grouping.
Pesticide’s share of farm production expenses has grown significantly from less than a 1% share prior to 1960 to a high of nearly 5% in 1998.
The cost share increase that occurred through 1980 was attributable both to increased total use and to rising per-unit costs, while the increase in cost share between 1980 and 1998 was due almost solely to higher per-unit prices paid. The total pounds of active ingredients of farm chemicals applied to crops rose steadily from early 1960 until about 1980, after which total pounds applied remained relatively unchanged.
However, quality improvements in the mix of pesticide ingredients, their ability to kill selected target pests, and the increasing ability of farmers to better target pesticide applications have continued through the 1990s.
These and other quality improvements have limited growth in usage rates since 1980, but have contributed to increases in per-unit prices paid through the mid-1990s.
Fertilizer Production Costs. In 2002, fertilizer expenditures accounted for about 5% of agricultural production expenses. However, they were the single largest outlay among farm energy expenditures, with a 34% share of the $28 billion of total energy expenses in 2002. That same year, fertilizer also represented the largest single source of farm energy (measured in Btu’s), with a 29% share.
Total fertilizer use by U.S. agriculture has averaged nearly 20 million metric tons since 1991 (see Figure 9). Of this total,
- nitrogen-based fertilizers comprise the largest portion, with a 56% share compared with
- 24% for potash and
- 21% for phosphate.
The demand for fertilizer depends on several factors, including
- soil type and fertility,
- crop rotations, and
- relative prices of both inputs and outputs.
Many, if not most, crops grown in the United States benefit from routine application of commercial fertilizers.
Fertilizers provide nutrients that enhance both plant growth and crop yield.
Canada is the traditional source for most U.S. nitrogen imports (accounting for about 40% of total imports since 1989).16
However, since 2000 the United States has increased the share of nitrogen imports from other sources, particularly from
Middle Eastern countries such as
- Qatar, and
- Saudi Arabia,
but also from
- Trinidad and Tobago, and
Fertilizer Prices are Linked to Natural Gas Prices.
U.S. fertilizer production is closely linked to energy availability, particularly natural gas. Natural gas is the key ingredient in the production of anhydrous ammonia.
Anhydrous ammonia is used directly as a nitrogen fertilizer and as the basic building block for producing most other forms of nitrogen fertilizers (e.g., urea, ammonium nitrate, and nitrogen solutions).
Natural gas also is used as a process gas in the manufacture of these other nitrogenous fertilizers from anhydrous ammonia. As a result, natural gas accounts for 75% to 90% of costs of production for nitrogen fertilizers. In addition, natural gas is an important input in the production of diammonium or monoammonium phosphates (accounting for 15% to 30% of production costs), and potash (accounting for as much as 15% of the production cost).
Because fertilizer prices are closely linked to natural gas prices through anhydrous ammonia, these prices move in tandem as anhydrous ammonia prices follow natural gas prices, while the prices of other nitrogen fertilizers in turn follow anhydrous ammonia’s price (see Figures 11 and 12.)
Phosphate and potash prices are less closely linked to natural gas than are prices for nitrogen fertilizers (see Figure 13).
Higher fertilizer prices encourage two potential responses:
(1) lower fertilizer application rates on the current farm planting mix; or
(2) the planting and production of crops that are less dependent on fertilizer.
Although nitrogen fertilizer application rates tend to be higher for various fruit and vegetable crops, field crops are planted on dramatically larger areas (see Figures 14 and 15). As a result, total fertilizer usage is highest for those crops that are planted to the greatest area — corn and wheat, with rice, cotton, and sorghum trailing far behind (see Figure 16).
Agricultural Prices-Paid Index (PPI).
- USDA’s agricultural PPI suggests that fuel and fertilizer prices have been significantly more variable than pesticide prices (see Figure 17).
- The impact of possible oil or natural gas price rises on agriculture can be significant, especially for field crop production, given the dependence of farming on petroleum products and the limited scope for fuel switching.
- In addition, the agricultural sector is particularly vulnerable to natural gas price increases due to the important role natural gas plays in the manufacturing of fertilizer.
Agricultural Energy Use by Activity
Total production expenses and the relative importance of energy costs vary greatly both
- by production activity and
- by region.
- Although there are many kinds of farm operations performed by the different farm types, nearly all mechanized field work, as well as marketing and management activities, involve machinery (such as tractors and harvesters) as well as trucks and cars that are dependent on petroleum fuels.
- Grain dryers and irrigation equipment are often more versatile in that they can be powered by petroleum fuels, natural gas, or electricity, while electricity is the primary source of power for lighting, heating, and cooling in homes, barns, and other farm buildings.
According to census data, energy expenses in agricultural production in 2002 were $24 billion, composed of $18.4 billion on crops and $5.7 billion on livestock production.
Energy costs represented nearly 14% of total U.S. agricultural production costs. In terms of energy’s share of costs within each major production activity,
- 23% of crop production expenses were attributable to energy costs, compared with
- only 6% for livestock production outlays.
The higher the share of total production costs accounted for by energy, the more sensitive a production activity is to energy price or supply fluctuations.
Major Field Crops.
Major field crop production traditionally requires several passes over the field, either with a tractor pulling some type of equipment involved
- in field preparation,
- fertilizer and chemical applications, or
- harvesting, or
- with a specialized machine that may perform one or more of these functions.
Fuel consumption depends on the fuel efficiency of the particular machine involved, the number of passes over the field (determined largely by
- the tillage practice employed), and
- the size of the field.
Indirect energy use in the form of pesticides and fertilizers varies widely across crops and regions depending on
- weather and soil conditions as well as
- production practices.
A significant portion of U.S. field crop production is irrigated each year, requiring further energy to operate the pumping equipment. In 2002, approximately 55.3 million acres, or nearly 13% of the 434.2 million acres of cropland — for all field, forage, vegetable, and tree crops — were irrigated (see Table 4).
The use of irrigation varies from year to year based on weather and soil moisture condition. For example, in 1997 nearly 16% (67.8 million acres) of the 425.2 million acres of total cropland were irrigated.
Also, irrigation use can vary substantially based on the crop grown —
- 100% of the 1997 rice crop was irrigated
- compared with only about 6% of wheat production.
Once harvested, most field crops require additional types of energy-related on- farm processing before being sold. Harvested crops with a high moisture content generally undergo drying to meet storage and processing requirements.
Other crops, such as cotton and tobacco, require other types of energy outlays.
Cotton must be ginned to separate the lint from seeds and foreign matter.
Tobacco has to be cured — a process of heating and drying to develop and preserve the potential quality, flavor, and aroma of tobacco — before it can undergo processing into cigarettes or other products.
According to the 2002 Agricultural Census (see Table 3), the highly aggregate category of “major field crops” was the largest agricultural energy user — both in total outlays at $13.6 billion and as a share of production costs at 27%. Furthermore, “major field crop” energy expenses accounted for 29% of the total energy costs expended by U.S. agriculture.
Production expenditure data for 2003 from the Agricultural Resource Management Survey (ARMS) as reported by the Economic Research Service (ERS) of USDA suggests that there is considerable variation within the “oilseed and grain” category (see Table 5). According to ERS agricultural production cost estimates,
- energy costs represent about 29% to 30% of total production expenses of rice, barley, and peanuts,
- but only 14% of total production expenses of soybeans.
For three of the four most extensively planted field crops in the United States —
- and cotton
- (soybeans being the exception)
— energy costs represented 22% to 27% of total production costs. As a result, year-to-year crop selection and profitability are potentially more sensitive to energy price and supply fluctuations for major U.S. program crops than otherwise indicated by the aggregate “major field crop” aggregation of Table 3.
Please see this link for further details: http://www.nationalaglawcenter.org/assets/crs/RL32677.pdf