AUBURN, May 10---Despite the concerns of some critics, advances on two different scientific fronts have enabled farmers to make great strides in protecting soil and water quality, says one expert.

Used in combination, these advances will result in more organic matter remaining in the soil, resulting in enhanced soil quality and lower rates of erosion. Also, by ensuring more carbon remains in the soil, they even may help reduce releases of greenhouse gasses into the atmosphere – a factor linked with global warming.

These advances stem from the increasingly routine and widespread use of Roundup, a herbicide that is considered especially friendly to the environment.

"Unlike other herbicides, it (Roundup) is very degradable, meaning that it’s broken down quickly by microorganisms after its application and doesn’t linger a long time in the environment," says Dr. Jim Hairston, an Alabama Cooperative Extension System water quality scientist. "In another form, it’s even being used to kill aquatic weeds – something that wouldn’t have been considered with other, less environmentally friendly herbicides."

Even more important, Hairston says, is the way Roundup is being used in combination with crops that have been genetically modified to survive herbicide sprayings – an advance that has enabled producers to avoid using other, less environmentally friendly chemicals.

"When you have a genetically engineered crop capable of surviving applications of herbicides, even while other weeds are being killed around it, you’re talking about something that offers great environmental benefits," Hairston says.

Before the advent of Roundup-resistant crops, producers typically had to apply a battery of herbicides at different times during the growing season to combat particular weeds. Many of these herbicides, especially those with chlorinated hydrocarbons, lingered for a long time in the environment because of their slow decomposition by microbes.

Roundup, on the other hand, is a broad-spectrum herbicide capable of killing many different kinds of weeds with only one application. Used in tandem with genetically modified crops, it has enabled producers to make drastic reductions in herbicide applications.

Without this new approach, producers still would have to rely on several applications of different herbicides throughout the growing season, many of which may contain chlorinated hydrocarbons.

While the passage of the Food Quality Protection Act of 1996 resulted in the phasing out of many herbicides with chlorinated hydrocarbons, many of the products developed as alternatives also presented their own set of problems.

Ironically, because they were designed to act on their targets and dissipate quickly, they often tended be more toxic to humans.

The use of Roundup, which is friendly both to humans and the environment, provides a solution to this dilemma.

Equally significant, the use of Roundup in conjunction with resistant crops may help reduce one of the effects associated with global warming, a problem stemming from excessive levels of greenhouse gases in the atmosphere.

In fact, the combination of Roundup and Roundup-resistant crops already has enabled producers to reduce the amount of tillage that otherwise would be required to keep troublesome weeds under control.

With less soil being disrupted from tillage, more carbon is retained in the soil – carbon that otherwise would be released into the atmosphere and contribute to higher levels of greenhouse gases.

This practice also contributes to higher levels of soil fertility as well as land that is more resistant to high-intensity storms. Without this protection during high-intensity storms, soil and pesticide residues are washed off into nearby lakes and streams.

Some critics have alleged that herbicides used in combination with genetically altered crops will result in new generations of weeds that are superresistant to herbicides.

However, Hairston says critics are overlooking an important issue. Just as medicine always has coped with the resistance of disease-causing microbes by developing new antibiotics, herbicide researchers will adapt to the threat of resistant weeds merely by developing newer, more improved herbicides.

Advances in genetics, he says, will only enhance this process, he says.