Biotech crop varieties first became available for commercial use in the U.S. in 1996. By 2011, the technology accounted for 90 percent of the upland cotton planted, 94 percent of soybeans and 88 percent of corn. For other crops, adoption of biotech varieties has been limited or nonexistent.
A recent study from Ohio State University compares the trend in U.S. average yields since 1995 with the trend that existed from 1940 through 1995, a period that predates commercial biotech varieties. The year 1940 approximates when the average yield of most U.S. crops began increasing, due in part to traditional breeding methods.
- While the yield trend increased for all 3 biotech crops after 1996, the yield trend increased for less than half of the crops (4 of 11) for which biotech varieties are of limited importance. This finding does not prove that biotechnology is the reason for the higher yield trend for corn, cotton, and soybeans. It only reveals that the evidence on linear yield trends is not inconsistent with such a conclusion.
- Over 10 years, the higher yield trend translates into a harvest yield that is higher in these crops: 69.1 pounds higher for cotton, 0.6 bushels higher for soybeans, and 1.6 bushels higher for corn.
- This addition to yield is 7.9 pecent of the highest harvest yield observed for cotton, 1.4 percent for soybeans, and 1.0 percent for corn. Thus, for corn and soybeans, the increase in yield trend since 1995 is not large.
The study was prepared by by Carl Zulauf, Ohio State University, and Evan Hertzog, Metro High School Junior Department of Agricultural, Environmental and Development Economics, Ohio State University.