U.S. farmers have adopted genetically engineered (GE) crops widely since their commercial introduction in 1996, notwithstanding uncertainty about consumer acceptance and economic and environmental impacts. In terms of share of planted acres, soybeans and cotton have been the most widely adopted GE crops in the U.S., followed by corn.
The tables in this product provide data by year, State, and genetically engineered seed trait obtained by USDA's National Agricultural Statistics Service (NASS) in the June Agricultural Survey (2000-15). Because the June Agricultural Survey began to include genetically engineered (GE) adoption rates for corn, cotton, and soybean in 2000, we use other sources for estimates of GE adoption rates at the national level for 1996-99.
The NASS June Agricultural Survey
The 2000-15 GE adoption data were collected as part of the June Agricultural Survey that NASS conducts during the first 2 weeks of June and publishes 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, were 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 (non-GE) were excluded from this portion of the survey. Insect-resistant varieties include only those containing the gene from the soil bacterium Bacillus thuringiensis (Bt). Seeds that have both herbicide tolerant and insect resistant traits are referred to as "stacked."
According to NASS, the States published in these tables represent 81-86 percent of all corn planted acres, 87-90 percent of all soybean planted acres, and 81-93 percent of all upland cotton planted acres (depending on the year).
The acreage estimates are subject to sampling variability because all operations planting GE varieties are not included in the sample. The variability for the 48 corn States, calculated by NASS using the relative standard error at the U.S. level, is 0.3-1.8 percent for all GE varieties (depending on the year), 1.6-5.9 percent for insect-resistant (Bt)-only varieties, 1.6-3.8 percent for herbicide-tolerant-only varieties, and 0.6-10.8 percent for stacked gene varieties. Variability for the 31 soybean States is 0.3-0.8 percent for herbicide-tolerant varieties, depending on the year. Variability for the 17 upland cotton States is 0.6-2.2 percent for all GE varieties, 4.6-21.4 percent for insect-resistant (Bt)-only varieties, 2.6-12.8 percent for herbicide-tolerant-only varieties, and 1.9-11.6 percent for stacked gene varieties.
Other Data Sources
Because the June Agricultural Survey began reporting data on genetically engineered (GE) adoption rates for corn, cotton, and soybean varieties in 2000, two other USDA surveys are used to provide estimates of adoption rates for these three GE crops for 1996-99:
Agricultural Resource Management Survey (ARMS) (for 1996-98). The ARMS surveys developed by the Economic Research Service (ERS) and the National Agricultural Statistics Service (NASS) of USDA have been conducted annually for selected crops since 1996. These surveys solicit information about farmers’ input choices, their technology use (including the use of genetically engineered crops), their management techniques, their yields, and their financial conditions. Each survey includes 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
Objective Yield Survey (for 1999). The 1999 adoption data are based on responses to the 1999 Objective Yield and Farm Operator Survey. 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 States accounting for between 61 and 71 percent of U.S. production. 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 survey was conducted primarily by telephone with some use of mail and personal interviewers. Herbicide-tolerant varieties include those developed using both biotechnology and conventional breeding techniques (non-GE). Insect resistant varieties include those containing Bt. Notably, these data are intended to show trends in production practices but are not recognized as official estimates by USDA's Agricultural Statistics Board.
Comparability Across Surveys
Data from the three surveys are not 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 GE crops. Consequently, the coverage of the three surveys often differs. There are also differences in the base acreage used to calculate the percentage of adoption (unlike the other surveys, which report adoption rates in percent of planted acres, the Objective Yield Survey reports adoption rates in percent of harvested acres), and differences in the questions' language.
See the ERS publication Adoption of Bioengineered Crops for additional detail about each of the previously mentioned surveys.