Chemical dependency and no-till practices: Is it real? If so, is it a concern?

While talking with my uncle, an ag lender, the other day I was confronted by a common assumption when it comes to no-till: “If you no-till, you have to use more herbicides.” I was struck by the conclusiveness in his voice. His observation means he was operating on three assumptions: no-till requires a lot of herbicides, tillage requires significantly less herbicides, and herbicide usage is the key measure by which to gauge no-till for its impact on the environment or bottom line. The simple reality is each of these assumptions misses important facts or realities that, when fully considered, would invalidate each of the assumptions. 

Let’s take each assumption one by one:

The basis for this assumption is that, by foregoing tillage, a grower is eliminating an efficient tool to terminate weeds, and therefore must mean no-tilled soils require an increased reliance on herbicides. What is missed here is the full range of other weed management tools available to growers. Certainly tillage and herbicides are the most common, but other effective—and perhaps more beneficial—strategies include residue management, crop rotation, and cover crops.

While tillage can terminate existing weeds, tillage can also create loose, bare ground—the perfect seedbed for weed seeds to germinate. In essence, tillage increases weed germination and growth. No-till minimizes weed germination and growth by utilizing residue on the soil surface (among other strategies mentioned previously). Another reality here is that nature abhors a vacuum—any farming strategy that seeks to maintain bare soil between cash crops (both between rows and between cash crop years) will require a higher use of weed management practices and tools to inhibit weeds… especially when that bare soil is loose.  Keeping the soil covered significantly reduces weed germination and growth, reducing the need to implement more weed control measures.

Herbicide usage can certainly negatively impact the environment when overused. But focusing on this means ignoring the environmental impacts from tillage practices, including significant soil erosion and water quality degradation. Also, this assumption discounts or ignores the operating costs associated with tillage. From fuel, to labor, to equipment ownership, to maintenance, every tillage pass costs between $16 and $25 per acre and often much more as fuel prices increase.

Additionally, let’s not forget about all of the productivity benefits of reducing tillage or implementing no-till has for a farm, including: 

• Improved soil structure creating better drainage of excess moisture
• Increased water holding capacity to survive droughts 
• Improved soil biology and soil organic matter to increase soil productivity 
• Host of other production benefits

No-till benefits a farm in many ways, from profitability to soil health, and there is more to consider than herbicide use assumptions. 

By Ryan Stockwell, Indigo Ag Senior Manager of Grower Engagement and Wisconsin Farmer