Data Sources
Three USDA surveys provide agricultural production data for
the adoption of genetically engineered (GE) corn, cotton, and soybean
varieties:
- Agricultural Resource Management Survey (ARMS) (for
1996-98)
- Objective Yield Survey (for 1999)
- June
Agricultural Survey (for 2000 and beyond)
1996-98 Data - The NASS/ERS ARMS Surveys
The ARMS surveys developed by the Economic Research Service (ERS)
and the National Agricultural Statistics Service (NASS) of USDA
are conducted annually starting from 1996. These surveys link data
on the resources used in agricultural production to data on use
of technologies (including the use of genetically engineered crops),
other management techniques, chemical use, yields, and farm financial/economic
conditions for selected field crops. Each survey included three
phases: screening, obtaining production practices and cost data,
and obtaining financial information. The number of States covered
by the surveys varies by crop and year, but each survey includes
States that account for between 79 and 96 percent of U.S. acreage
in the specified crop.
1999 Data - The NASS Objective Yield Survey
The 1999 adoption data are based on responses from the seed variety
questions on the 1999 Objective Yield and Farm Operator Survey conducted
between September and October to gather information on expected
yields. The information was published in October 1999 in the NASS
report Crop Production. The Objective Yield Surveys (OYS) for corn,
soybeans, and cotton were conducted in the major producing States
that account for between 61 and 71 percent of the U.S. production.
NASS conducts objective yield surveys in major corn, soybean, and
upland cotton producing States each year. Randomly selected plots
in corn (for grain), soybean, and upland cotton fields are visited
monthly from August through harvest to obtain specific counts and
measurements. The farm operator survey was conducted primarily by
telephone with some use of mail and personal interviewers. Herbicide-tolerant
varieties include those developed using both biotechnology or conventional
breeding techniques. Insect resistant varieties include those containing
Bt. These data are intended to show trends in production practices
but are not official estimates of USDA's Agricultural Statistics
Board.
2000-07 Data - The NASS June Agricultural Survey
The 2000-07 adoption data were collected as part of the June Agricultural
Survey that NASS conducted the first 2 weeks of June and published
at the end of June in the NASS report Acreage. Enumerators conducting
the area survey contact all farmers having operations within the
sampled segments of land and account for their operations. Farmers
in the list survey sample are contacted by mail, telephone, or personal
interview to obtain information on their operations. Responses from
the list sample, plus data from operations that were not on the
list to be sampled, are combined to provide another estimate of
planted and harvested acres. Regarding GE crops, randomly selected
farmers across the United States were asked during the first 2 weeks
of June if they planted seed that, through biotechnology, was resistant
to herbicides, insects, or both. Unlike previous surveys, herbicide-tolerant
varieties in this survey include only those developed using biotechnology.
Conventionally bred herbicide-tolerant varieties were excluded from
the survey. Insect-resistant varieties include only those containing
Bt. Stacked gene varieties include those containing genetically
engineered traits for both herbicide and insect resistance.
Comparability Across Surveys
Data from the three different USDA surveys are not directly comparable
because none of the surveys were specifically designed to collect
data on GE varieties. Rather, questions on adoption of GE crops
were added to different USDA survey instruments whose main objective
was not measuring the extent of adoption of these crops. As a consequence,
survey coverage among the three types of surveys often differs.
There are also some differences in the base acreage used to calculate
the percentage of adoption (unlike the other surveys, which report
adoption rates relative to planted acres, the Objective Yield Survey
reported the adoption rates relative to harvested acres), and the
questions related to GE crop adoption are not identical in different
surveys. See the publication Adoption of Bioengineered Crops for more detail about the different surveys. In particular,
adoption data for 1996-99 include herbicide-tolerant corn and soybeans
obtained using traditional breeding methods (non-GE). The more recent
data (2000-2007), on the other hand, excluded these varieties.
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