Round-up resistant weeds are many farmers’ nightmare. They suck up time and resources. Call in a consultant and they may suggest “use another pesticide.” When I suggested integrated crop-livestock systems to an Australian extension agent wringing his hands about how fast pesticide resistance genes can spread, he said, “sure, we used to rotate crops with pasture, but now we grow one crop of no-till wheat every year and take the rest of the year as vacation at the beach.” To say that pesticides have provided some farmers temporary yield boosts and improvement in their quality of life would probably be an understatement.
But those temporary gains seem to be at risk. Recent articles chronicle Roundup‘s dwindling effectiveness. Still, I think it’s important (if unpopular in some communities) to recognize that glyphosate has been an effective tool for around 30 years. Demonizing Roundup prevents us from learning Roundup’s lessons, both the good and the bad.
Farmers and ecosystems alike have benefited from Roundup in some ways, especially through the most common forms of no-till agriculture. In the most common no-till implementations, the bio-control of cover cropping (through competition and sometimes allelopathy) is combined the chemical control of glyphosate. This combination helps growers replace tillage and reduce erosion. When glyphosate application is timed so that soils are dry and rain is not forecast (for about a week), it gives a chance for the chemical to break down and prevent its escape into the environment.
Expanding our pest management toolkit beyond “spray-first” reduces build-up of pesticide resistance that is causing an epidemic in “Roundup Ready” systems. Even the farmers at Rodale used glyphosate when they were perfecting usage of their really cool roller-crimper.
In the same way that I think it’s important to learn from the Roundup era, I think it’s important to realize that organic can be very much like the high-input conventional systems that many in the organic food movement hope to replace. When you replace synthetic inputs with organic, consider that you might be trading the carbon cost of manufacturing a synthetic chemical with a similar carbon cost in terms of fuel. Similarly you may be offsetting a reduced carbon footprint from synthetic inputs with increased fuel costs if you are using more frequent tillage as a way to control weeds.
The reality is that no system is perfect. Learn what you can from farmers that you meet. Experiment. Relying on Roundup every year to control weeds is just asking for trouble, but a one-time application of glyphosate could save your bacon when you have a troublesome rye cover crop that just won’t die. It could also save you a huge loss of organic matter if your primary tool for control is tillage. Replacing “spray-first” with “till-first” can result in just as many super weeds and still have negative environmental outcomes such as erosion and greenhouse gas emissions. So please remember, the problem isn’t Roundup. It’s the problem of abusing your “best” tool.