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.
2000-11 Data - The NASS June Agricultural Survey
The 2000-11 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 (2000-11), on the other hand,
excluded these varieties.
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