To Till or Not to Till?

By Juanita Polegi, P.Ag.

SSCA Soil Conservationist

To till or not to till is the question many farmers are posing this winter as they face the coming spring. As margins become tighter, finding the least costly method for getting the crop into the ground and growing is essential. For that reason, pre-seed tillage is getting a second look from some producers. At some of the meetings we've attended this winter, we've heard a few producers say that they're not going to bother with pre-seed burn-off this spring because it's "too expensive". Instead, they'll make a couple of passes with the cultivator prior to seeding and get the volunteers, winter annuals and annuals that way.

When we hear these statements, of course, the alarm bells go off. It may seem that the cost of a couple of tillage passes prior to seeding is less than going to the local dealer and purchasing Roundup. But when you pencil out the two systems and consider the trade-offs, there's a difference.

Darwin Kells, Farm Business Rep. with Monsanto Canada, figured out the cost of two passes with the cultivator in the spring (Table 1) vs. the costs of running a sprayer with 0.5 L/ac Roundup Transorb in the tank (Table 2).

Table 1 Cost of Tillage (cost/acre 2 passes)

Based on a Ford 936 tractor and a 40 foot Bourgault cultivator

Table 2 Cost of Spraying Pre-Seed Roundup(cost/acre)

Based on a JD 4555 tractor and a 100 foot Brandt sprayer

*Suggested Retail Price

In terms of cash and fixed costs, the difference between the herbicide and the tillage is $0.57 in favour of the herbicide. But more than the cash costs need to be factored into this equation. With each pass of the cultivator, 1/2 inch of soil moisture is lost. An additional inch of soil moisture is lost for every 10 days winter annuals, early emerging annuals and volunteers are allowed to grow in the spring. As for wild oats, two passes with the cultivator, at best, will achieve only 60% control. And leaving the soil bare leaves it vulnerable to the forces of the wind.

In contrast, an application of Roundup at 0.5 L/ac will maintain the soil moisture and achieve 90% wild oat control. In addition, the fields are readied for seeding more quickly with a one pass application of Roundup than 2 passes with the cultivator. And of course, the sprayer doesn't pull out stones like the cultivator. Standing stubble or stubble worked once last fall will protect the soil against wind erosion.

Pulling out the cultivator early this spring means you don't have to visit the dealer to buy product up front. However, in the long run, an application of Roundup will reduce fuel usage, achieve good weed control, reduce the risk of early spring moisture loss and reduce the risk of erosion. With fuel prices on the rise and much of the province short on soil moisture, hitching up the cultivator may not seem so attractive after all.