A little goes a long way working with herbicides

FORT COLLINS – Research scientists are working to develop better methods of applying herbicides to weeds in farm fields, an advance that could save growers thousands of dollars each year.

But how quickly those methods may be adopted by area producers will depend on the successful demonstration of the effectiveness of the techniques.

“Growers aren’t going to do anything until they’re convinced it’ll save them time and money,´ said Lori Wiles, a weed ecologist and site-specific weed management project leader for the Water Management Unit of the Agricultural Research Service of the U.S. Department of Agriculture in Fort Collins.

Site-specific management is a new concept aimed at helping growers selectively apply herbicides so more is sprayed on patches of their fields that need them most and less where weeds are less of a problem. The goal is to improve yields, cut herbicide costs and help reduce groundwater pollution.

Site-specific not new concept

Wiles said site-specific – or precision agriculture – field techniques aren’t exactly new, with site-specific fertilization now in use more than two decades. The success of that method has created interest in site-specific seeding, irrigation, herbicide application – even site-specific manure spreading.

It’s a marriage of new technology – primarily the GPS or Global Positioning System – and a grower’s intimate knowledge of his or her particular field conditions learned over the years. Armed with both, the grower can “map” the field with the location of troublesome weed patches and feed that information into a computer on board a tractor and then apply the herbicide more selectively.

However, a simple weed-mapping technique that’s easy for farmers to use is still being perfected, Wiles noted, which is just one of the obstacles to adoption of the management plan. One is the fact that selective spraying will result in some weeds being missed, a situation less likely with uniform spraying.

“For weeds, (site-specific management) is going to be a tough sell because farmers don’t want to have any weeds in their field,” she said.

Dale Shaner, another Fort Collins plant researcher, said regional growers are still wary of adopting the new program. “I can’t say it’s been practiced too widely yet,” he said. “The technology’s still being developed and certain herbicides are so cheap that farmers don’t want to take the time to use it.”

Shaner said some herbicides are expensive, costing up to $40 per acre. With estimated herbicide reductions of 30 to 70 percent using site-specific management, that can add up to some substantial savings for growers.

“It saves the farmers money by only putting out what you need,” he said. “That’s the whole idea behind site-specific management. You can maintain yield and weed control and use less herbicides and pesticides.”

Time may be ripe

Shaner said the time for adoption of site-specific field techniques has arrived. “Now, with GPS and other things, farmers’ tractors can essentially drive themselves and they know where they’re at in the field and know exactly where they’ve sprayed and haven’t sprayed.”

Byron Weathers, who produces corn and wheat on a 2,200-acre farm near Yuma, has been using site-specific techniques for seeding his fields, and is interested in adopting the practice for weed control.

“I guess if they can figure out how to track what’s out there and what needs to be sprayed and what doesn’t need it, it would be fantastic,” he said.

Weathers is concerned about not only saving money on herbicide costs but also in helping preserve the environment. “It’s going to be a great deal if we can do that at some point.”

Although he’s been using site-specific seeding for the last several years, like most farmers, Weathers is skeptical of new technology. “You can’t play with something that might not work,” he said. “It’s going to take a lot of field days that show people exactly what it can do and how it can benefit them in a real business operation.”

Mark Sponsler, acting executive director of the Colorado Corn Growers’ Association based in Greeley, said he believes producers will eventually get on board with the new technique.

“I say that for a couple of reasons: Economically, it makes sense to only use as much herbicide as necessary and where necessary. That’s good both economically and environmentally.”

But Sponsler said the “upfront costs” for producers to outfit their field equipment with GPS and other technology is no doubt keeping some from using the practice. “When it becomes more economical it will no doubt be more widely used.”

One more useful tool

The Corn Growers’ Association is supportive of site-specific technology in general, Sponsler said, and he expects site-specific management will eventually be another tool to help growers improve their yields while reducing their costs.

“I expect that it will come,” he said. “The industry has shown some remarkable advancements in the last five years.”

Sponsler believes farmers will embrace the technique as much for its potential environmental benefits as its potential cost benefits. “They (farmers) are really the original environmentalists,” he said. “The public often overlooks the fact that if a producer has a negative environmental impact on his land he’s risking his future.”

At the Agricultural Research Service’s Water Management Unit in Fort Collins, one of the driving reasons for developing site-specific management has been to protect groundwater and stored water from herbicide contamination. Wiles said the U.S. Environmental Protection Agency provided a grant to help researchers develop software that growers can use to map their fields, assess their weed infestations and figure potential cost savings. The software is downloadable on the research service Web site.

“It’s not actually for application of herbicides right now, it’s more of an educational tool,” she said. “The benefit can really vary depending on the weeds in your field.”

Wiles admits she has her work cut out for her. But word is gradually getting out, she notes.

“I’ve had hundreds of downloads of the software from around the U.S. and overseas,” she said. “And I’m happy to go anywhere people invite me.”

Wiles said some universities, including CSU, are now offering courses in site-specific field techniques and she predicts they will be more frequently adopted as more young farmers become exposed to them.

Shaner said growers will always be interested in methods that will help them better manage their operations.

“Each farmer is doing more and more acres to stay in business and has to be smarter about doing it,” he said. “This is one way to do that.”