Carbon Footprint of Organic Weed Control Much Higher than Use of Herbicides

Cultivating Grape Vineyard

Cultivating Grape Vineyard

Farmers have a choice for managing weeds. They can apply herbicides or use cultivation to remove weeds. It takes 2-3 cultivation trips to equal the effectiveness of a single herbicide treatment. As a result, organic farmers, who cannot use herbicides, release more carbon to the atmosphere than farmers who use herbicides.

“When it comes to farming, Monterey County winegrape grower Steve McIntyre believes in using the best management practices available. Some are conventional and some are organic. Bottom line: they’re sustainable.

McIntyre, whose office is in Soledad, farms about 800 acres of winegrapes in the county, which is fast becoming one of the state’s premier winegrape growing regions.

“To me, farming organically or biodynamically is like farming in a box. There are too many rules if you don’t have the opportunity to use the latest and best science to lower your carbon footprint.”

McIntyre points to weed control to illustrate his point of where organic farming has its limitations.

“When you cultivate the weeds in the vineyard, new weeds germinate and come roaring back fairly quickly, as opposed to using a good herbicide, which results in the weeds coming back much slower.

“If you cultivate you have to make two or three trips through the vineyard, as opposed to one trip with a sprayer,” he continued. So with conventional farming, you have less equipment, less air pollution, fewer natural resources to build the equipment and power the equipment.

“If you look at weed control with a carbon calculator, there is a huge difference,” he said. “If you look at organic weed control, the carbon footprint for that is two or three times greater than the carbon footprint of a good herbicide.”

Author: Adler, S.
Affiliation: Reporter.
Title: Winegrape grower approaches farming like evolving science.
Source: Ag Alert. April 15, 2009.

Jimmy Carter Was Right: Herbicides Have Improved Peanut Yields


In a 1977 Question-and-Answer Session with Department of Agriculture employees, President Carter recalled the tremendous growth in peanut yields on his Georgia farm which resulted when they stopped plowing. He credited research that showed that more plowing meant less yield. It turns out that he was right: the plowing spread disease that lowered peanut yield. Herbicides made the reduction in plowing possible and improvements in herbicides have continued to benefit peanut farmers.

“Improvements in weed management are a contributing factor to advancements in peanut yield. …Cultivation was traditionally an integral component in peanut weed management. New herbicide developments improved overall weed control and cultivation is no longer needed. This directly addresses the susceptibility of peanut to infection by soil-inhabiting fungi. There is a direct correlation between incidence of stem rot and displaced soil thrown on peanut plants from cultivation. Not needing to cultivate lessens disease epidemics and protects peanut yield. In 2013, 21 herbicide active ingredients were registered in the U.S. for weed control in peanut. In contrast, there were 12 herbicide active ingredients registered for use on peanut in 1980. Recently developed herbicides are more consistent, versatile, and have a broader-spectrum than earlier herbicides. …There were no selective postemergence herbicides registered in 1980 that controlled emerged grasses. In  2013, there were three postemergence herbicides registered for use on peanut to control annual and perennial grasses…. Registrations of these herbicides were major weed control milestones in peanut production and have largely eliminated yield losses from grasses that escaped earlier control efforts.”

Author: Johnson, W. C.
Affiliation: USDA-ARS, Tifton GA
Title: Yield Advances in Peanut – Weed Control Effects
Source: 2013 Proceedings of the American Peanut Research and Education Society, Inc.

Organic Growers Can Use Synthetic Herbicides When Planting a New Vineyard

Weedy Vineyard

Weedy Vineyard

Planting a new vineyard in a weedy field is a bad idea. Weeds would compete with the small vines for moisture, space, nutrients and light which would set back their growth. Thus, in establishing a new vineyard, growers need to clear the weeds out. Most growers use synthetic chemical herbicides when planting a new vineyard due to the high cost of hand weeding and negative effects of tillage. Using herbicides is an option for organic growers since the small vines do not produce grapes for several years which corresponds to the waiting time to be certified as organic.

“…weed management is the most expensive and technically challenging practice for organic grape production, and many organic farmers rely on mechanical and hand cultivation for weed control. Although these methods are highly effective, they are also labor intensive, more expensive, and their sustainability is questionable from a labor and environmental perspective.

Another option would be to use conventional production techniques that use synthetic herbicides during the establishment phase, and once established, transition the vineyard to achieve organic certification.”

Authors: Olmstead, M., et al.
Affiliations: Department of Horticultural Sciences, University of Florida.
Title: Weed control in a newly established organic vineyard.
Source: Hort Technology. December 2012. 22(6):757-765.