This question was answered by Kevin Folta on 10/13/13. He has provided an updated response below. https://gmoanswers.com/ask/i-am-interested-learning-more-about-how-biotech-seeds-improve-sustainability-can-you-provide
Sustainability is an important topic to anyone involved in agriculture. Let’s talk about sustainability on several levels, as “sustainability” means different things to different people.
Toward environmental sustainability, the GM insect tolerant crops allow much less broad-spectrum insecticide to be used, which has many advantages. Insect populations are more diverse, and abundant, except for those that directly harm the crop. Herbicide tolerant crops use a tiny amount (about ¾ of a liter per acre) of a low-environmental-impact herbicide that is relatively safe for humans to apply, and it breaks down quickly in the environment. It also has been shown that those of the herbicide-tolerant varieties decrease the need for tilling, leading to better topsoil retention.
Economic sustainability means a positive net balance between the cost of production and the value of the product. The best example is perhaps the Hawaiian papaya. Papaya farmers find the GMO papaya much more sustainable than non-GM, virus sensitive varieties. Yields are much better and there’s less need for insect controls. On the large agronomic farm the use of herbicide-tolerant and insect resistant crops decreases fuel and labor costs, while generally keeping yields the same or improving slightly. These are all positives in the area of economic sustainability.
There is so much more that can be done for sustainability. The most exciting innovations remain to be realized. There are new plants that require less water, a huge step in sustainability. There are plants that use fertilizers more efficiently. That’s good too from an economic and environmental standpoint.
We are seeing beautiful examples of effects on sustainability in the developing world. A nice example is the Bt Brinjal (eggplant). Farmers do not need to use insecticide, or at least cut back a lot on insecticide use, because they are using this product in Bangladesh. GM cotton has been a great success in many areas of India, increasing revenues for families that use it, and decreasing the number of insecticide treatments required in a growing season.
Sustainable food production boils down to maximizing output while minimizing inputs. The use of GM crops certainly has contributed to this equation and will continue to do so, as more strategies will be developed and deployed in the upcoming years.