I'll refrain from ragging on Mercola as a news/science source while writing this...

The effect would be very minor with crop residues. Practically every study done shows active forms of BT persisting in soil from crop residues, but it's really minor. Genetic material from residues was found, but it's effect on soil microorganisms was rather negligible. Since the gene expression of BT is systemic in the entire organism, it's safe to say root residue would be part of these studies as well as any leaf/stalk/grain/pollen residues. I can't venture an exact guess of how this would compare to ground up, dried grain alone...but I imagine the total applied would rarely be more than residues left on studied fields.

I have no idea if anyone's done a study on GM corn/soy meals applied to soils because it's rarely used as a soil amendment as it is for a variety of reasons, though some still have faith in it's use. That's another discussion, but as it is, it's not a commonly used amendment so study beyond basic soil nutrition/herbicide/fungal/microbe studies don't exist (that I know of).

As far as DNA "mixing" goes...transgenic mutation is quite rare and is less likely compared to a random mutation happening in an organism on it's own (without external input from another organism). I wouldn't worry about that aspect at all. To say there's "less than 1% of 1% of a chance" wouldn't begin to cover how little of a chance of this happening would be...and even then there's no guarantee any mutation would be a bad one or one with a measurable effect.

This post was edited by nc-crn on Sun, Jan 13, 13 at 22:40

The problem with these Genetically Engioneered Organisms is that so little research has been done on them that we have no idea what they will do. We do know that the products those plants have been modified so more of the product can be sprayed do have adverse affects on lower forms of life that might also adversly affect us. The problem with you using them is not that there may be any pesticide residue, because of the modification, but that the plants that have been modified are sprayed so heavily the residues from those plants will have large amounts of those pesticides.
As far as whether the DNA of these things added to these plants would mix with the DNA of organisms in your soil, these organisms have been around for eons and have not yet mixed naturally.

I agree with nc-crn. Again, another rational view.

I could never be against GMO, as farmers are only doing what they can to keep up with food needs...

See what I am getting at here? I hope....

kimmsr, you obviously haven't looked at the research that's been done on GMOs, so maybe you should do that before claiming "little" research has been done. I can type in topics related to GMOs in to almost any scientific database and get hundreds of studies back. People feign ignorance so often on this topic and say, "Well we don't know about X." when we often actually have a good understanding of what's going on. Usually when someone says we don't know much about something related to GMOs, it usually means they just didn't attempt to understand the basic biology and science that would have easily answered the question for them.

Let's take the two main GMOs for this topic, Roundup Ready soybeans, and Bt corn. Using glyphosate has been a huge step up from the herbicides of the past as far as safety and environmental impacts go. You're talking like we have huge herbicide loads on our crops, when in reality we're using much safer herbicides because of glyphosate resistance.

So what happens when corn and soybeans end up in the soil? Do you know what makes soybeans resistant to glyphosate? It's not some toxic chemical, the plant just processes chemicals different during it's normal metabolism. It's not different than taking a detour when you're driving, you just end up at the same destination. Bt from corn originally came from a soil microbe, so that DNA isn't anything new to the system either. There is nothing new to "mix naturally" in these cases.

Specifically, a lot of GMO research on crop residues and the effect on soil health was done in the early 00s when the question of the time was it's effect on soil health. These studies still continue since it's such a young field of research.

Legacy fields and trial cropping fields are/were sampled and tested heavily.

While it's impossible to get long-term conclusions out of these studies, the short-term conclusions were heavily skewed in favor of very little impact, if any at all found on soil health or organism mutation. That said, that's no reason to say there should be long-term bad conclusions to be expected. It's an issue people are keeping an eye on.

There's been a fear about the evolution of boll-worm resistance in cotton, but every time they find a possible resistant localized colony, they tend to not show up the next season. It's emergence as a population has been very erratic to the point of it being hard to find year-to-year.

One of the practices used by many farmers is the planting of a "trap crop" near their main fields which is non-GMO. It usually yields less, but the point of it's existence is to give pests a more attractive option for feeding and to lessen the impact of resistant pest populations from getting large. So far, it's working really well and it's more widely deployed than it's generally talked about. It's a good management practice in our new world of GMOs.

It's important to remember that GMO plants aren't just made and sent to market for decades. There is constant "tinkering" with seed formulations/availability and gene stack placements. It's not like there's a corn released and you're going to be able to plant that same one for a decade. It's not just improvements that's being bred in, it's practically akin to a rotation method for GMO crops to help slow the kinds of organism adaptations that may be expected in a population constantly exposed to the same thing over a long period of time.

This post was edited by nc-crn on Wed, Jan 16, 13 at 7:27

A recent Mercola article said:
DNA from GE organisms is not readily broken down by soil microbes, and this foreign DNA can mix with the DNA of these microbes to create bizarre strains, toxins, and otherwise interfere with the biological system that controls soil�s fertili

The most polite way to express myself is to say that Mercola makes things up because he is paid to manufacture controversy in order to attract advertisers.

DNA is DNA. What scientists call "lateral transfer" of genetic material (from one species to an unrelated species) happens all the time.