Economic and environmental impacts of stacked transgenic events on soybean and corn

Abstract

Between 1996 and 2020, the Uruguayan government authorized twenty-eight genetically modified varieties of corn and soybean. This study investigates if the transgenic seed with stacked events with more than one agronomic characteristic in soybean and corn (HT and Bt), compared to those of one event (HT or Bt), shows productive, economic and environmental advantages in the period between 2010 and 2020 in Uruguay. To achieve the proposed objectives, a partial budgeting method was developed for the economic analysis. In addition, the mean difference for soybean yields was estimated with the “Bootstrap” and “Anova” techniques. The consumption of herbicides and insecticides in trans-genic soybean and maize crops was estimated, comparing it with national imports. Toxicity indices for mammals, bees and chemical persistence in soil were constructed with the evolution of the main herbicides and insecticides according to toxicological category applied to soybean and corn crops. Finally, the number of insecticide applications entrances to field was also weighted and then validated through the Poisson technique. Results showed economic advantages, mainly for corn crops with three stacked events. While the soybean varieties with stacked events did not have differences in yield, a decrease in the entries to field due to insecticide applications was observed, which does not compensate for the higher cost of the seed. The results obtained showed a general improvement in the evolution of less toxic insecticides for mammals and bees, but with an increase in applications with non-glyphosate herbicides.