The biggest challenge to rotation planning is finding the balance between short term profits and long term planning
There was a joke that once made the rounds about farmers moving to a two-crop rotation: canola and snow. It’s funny, but it also highlights the challenge that all farmers face when it comes to crop rotation planning: how to keep chemical rotation and pest issues in check, but still make money?
It’s not always an easy question to answer. The ideal four-year rotation, cereal-oilseed-cereal-pulse, simply isn’t possible in all geographies, and the economics of some crops, canola in particular, can make the risky practice of tightening the rotation too attractive to resist.
“It’s like playing a chess game,” says Kent McKay, agronomist and co-manager of Double Diamond Farm Supply in Boissevain, Man. He acknowledges that effective rotation planning can be frustrating, and that it’s difficult to forgo the profit motive in favour of the agronomic one occasionally, but the payoff is worth it. “Good planning puts you in control, rather than having to put fires out afterward.”
Here is some of his advice.
1. Think long term; act short term
McKay sits down with customers every fall to look at the year ahead. “We get out the herbicide crop rotation spreadsheet and make plans for the growing season coming up.” But it’s not just one year at a time. “We discuss situations we want to avoid, like if you do X this year, it forces you into that crop or herbicide next year. You have to look at what pitfalls to avoid.”
He thinks that planning three to five years out is reasonable, but once the plans are made, revisit them every fall or winter to see what needs adjusting. Changes might include new varieties you want to try, commodity market indicators, new pest pressures or a need to incorporate newly acquired land into your plans.
Think of your crop rotation plan as a living document, says McKay. It’s meant to be altered.
2. Have a Plan B
“The economics of canola have been pretty appealing,” says McKay. That’s put a lot of pressure on farmers to seed it more often than conventional wisdom says they should. The risk is increased pest pressure from all sides — disease, weeds and insects.
“I’m not saying people shouldn’t take those risks,” says McKay. “But you have to know how you’re going to manage the problems if they happen. So if you choose crops that are more risky from a rotational standpoint, having a Plan B is always a good idea — understand what your options are.”
Of course, that applies to all rotational options, not just canola. If you planned a pulse crop, for example, but too much spring rain made timely seeding impossible, what’s your Plan B, and what are its implications for that field the following year?
3. Product placement
Chemical rotations are as important as crop rotations. The two go hand-in-hand, and while most farmers have a handle the concept of rotating herbicide groups to manage weed resistance, the matter of chemical rotation has a few more layers to consider.
Residuals, for example. Herbi-cides with residual activity can be extremely useful if you want to control multiple and late-emerging weed flushes. But these products can have big cropping implications for the following year.
Pulses, for example, have a limited number of herbicide options, and can usually follow a wheat crop just fine. But if the wheat crop has a resistant weed problem, grass or broadleaf, what do you do? The decision now becomes about where you will get the best use out of a Group 2, on the wheat or the lentils? If it’s the lentils, you need another plan for the wheat.
The key is good record keeping. “A good example in our area is carryover in soybeans,” says McKay. “You need good records so that when those decisions have to be made, there’s some basis from which to make them.”
Payback can be tough
Ultimately, a successful crop rotation plan finds the balance between making a profit today and protecting profit potential for tomorrow. In other words, choosing to put wheat on a field this year may not give you the same return on investment as canola, but it might make better sense in terms of what you need to put on that field in the future.
McKay recounts the story of a customer who had a huge Group 1 resistant weed problem. “It had us absolutely beat,” he says. As attempt after attempt failed to solve the problem, they finally turned to using old products in new ways and eventually cleaned up the field, returning it to profitability.
“The grower had to be really committed,” says McKay, adding that it took six years of strict discipline to recover the field, and six years of potentially reduced profit is a big price to pay for earlier rotational mistakes. †