On our farm we used GMO crops for two reasons:
We use Bt traits in our corn to control below ground pests that like to eat corn roots, and to protect the plant above ground as well.
The second reason is to expand the range of tools available to us for weed control via herbicide tolerance traits.
Allow me to explain further.
With Bt corn traits our crop is protected from infestations of particular corn pests. These pests must munch on a corn plant to be affected. One great benefit of this technology is that if an economically damaging level of corn rootworm or earworm comes along our crop will be protected.
We won't have to come in during the growing season to make a blanket pesticide treatment across the entire field. This means a sprayer is kept out of the field -- meaning it didn't need fuel to power the sprayer or water to carry the chemical. Fewer passes across a field also mean less soil compaction in the wheel tracks. And don't forget I didn't buy any chemical or pay an application fee to a custom sprayer. Because Bt targets specific pests, we are not spraying insecticide on the beneficial insects in our fields.
Lately we haven't had a great deal of corn pest pressure so we've been backing off on buying Bt traits to save money. We do still use seed treatments to ward off pests and disease early in the season. We stopped using soil applied insecticide in 2012, and that has been working out well for us so far. I attribute cutting that out of our management program to the success of Bt crops and weather patterns keeping the pest population below economic levels. This is working in our favor right now as corn prices are about half of what they were two years ago.
Herbicide tolerance is a great tool. There are several different traits on the market, but right now we are only using RoundUp Ready technology. All of our soybeans are Roundup Ready (RR). Some of our corn is RR and some is not.
For 2015, about half of our corn crop is non-GMO. Why? Because the facility we sell waxy corn to wants all non-GMO for the 2015 crop. Growing waxy is just like growing regular dent corn, but we get a $.55/bu premium. We grow popcorn too, and since there is no GMO popcorn it also is not RR. That being said, we generally do not spray any Roundup, also known as glyphosate, on our corn crop even on the RR acres. We rely on it for weed control in our soybeans, but we like to rotate to different modes of action to manage weeds in corn. Not relying solely on RoundUp in both crops is one way we can stave off herbicide resistance forming in our fields.
Corn has more and better chemical weed control options than non-GMO soybeans do. RoundUp works really well for us in soybeans. Marestail can be a little tough in our beans sometimes, but that's why we spray something else when we rotate to corn every other year. Yes, the marestail is resistant to glyphosate these days. There are other herbicide tolerant traits in soybeans like Liberty Link and Enlist is coming soon. So the tools available to kill weeds in soybeans are expanding, and that is a good thing.
Before RR soybeans came along we used to till the soil multiple times before the planter even put seed in the ground. Now we till one time or even zero times because we manage our weeds very effectively with RoundUp and sometimes we use a burndown before planting with residual activity that will capture newly emerging weeds early in the growing season before we make a post-emergent glyphosate application. Reducing our tillage passes greatly reduces our need for fuel. Tillage is our most fuel intensive operation on the farm. Reducing tillage also improves our soil structure which has a number of benefits including improved water infiltration and retention and reduced erosion.