Are you a Betty Crocker grain grower? That was the question producers attending the Manitoba- North Dakota Zero-Till conference recently held at Brandon, Man., were left to ponder. Jill Clapperton, a freelance consultant who discussed production practices there, says that phrase has been used to refer to people who look for a “just-add-water recipe” to grow crops. But there really is no universal best practise producers can turn to and expect to maximize their own efficiency.
“One size fits none,” she says. “And we’ve been trying to go one size. It’s OK for each farmer to have an individual system. What’s best practices for one farmer is not necessarily best practices for another.” Understanding and managing for the benefit of the whole agricultural ecosystem on their farm will allow producers to optimize their productivity, and eventually their profit margins. Trying to deal with specific production problems in isolation is inefficient and costly.
“We’re taking that whole-systems, holistic approach to looking at agricultural systems management,” says Clapperton. “Whether we integrate livestock or whether we don’t, it’s an agro-ecosystem.”
LOW ORGANIC MATTER
The problem many farmers now face is recovering from counterproductive agricultural practices used in the past, which have left fields with very low soil organic contents. As a result, the populations and diversity of soil microorganisms that cycle nutrients naturally have declined. Simply put, there just hasn’t been enough crop diversity in fields to sustain these populations. Farmers with that problem now need to apply ever-higher levels of inputs to achieve the same yields they saw in the past.
“We’re understanding more and more that diversity is a critical part of that (growing crops),” says Clapperton. “Above-ground diversity is a mirror of below-ground diversity.”
Kris Nichols, a soil microbiologist with the United States Department of Agricutlure, presented data at the conference that supported Clapperton’s assertion. It was based on research done in the U.S., which showed soil response to fertilizer inputs has diminished over the past few decades. Clapperton and Nichols agree that years of intensive tillage has been one of the primary causes; soil microorganisms can’t thrive when tillage is used on a frequent basis.
PLANNING AND MANAGEMENT
“I believe soil health starts when tillage stops,” says Glenn Bauer, an experienced, no-till farmer from North Dakota. But planning for the right diversity of crops is equally critical. “We think it’s important to get a rotation in place. Some years we have nine different crops.” That involves much more planning than many farmers may be used to. “It takes a lot more management,” he says.
And while many established no-till growers are now experiencing difficulty in getting residues to break down, Bauer has no problem with it. In fact, he has to take steps to ensure residue on his fields doesn’t break down too quickly. Planning proper crop rotations is key to that.
The crops Bauer plants go beyond just those he intends to harvest. “We use cover crops for (added) diversity,” he says. He seeds them to keep vegetative cover on fields after some early-season crops are removed, but only if crops are harvested before the end of August. “We don’t feel we get enough growth on them (cover crops) seeded after that,” he says.
Even though he believes strongly in the benefit of cover crops, he cautions farmers not to spend too much money on them. Each one has to make economic sense. “We try and stay under that $22 per-acre cost,” he says. And there is no need to make a field pass to terminate them. They are killed by frost in late fall. Despite leaving them standing, Bauer says he has never had any difficulty seeding into the stubble.
Having that additional diversity in the types of plant residues on a field helps keep the carbon-nitrogen ratio of the entire residue covering in balance, which allows soil organisms to efficiently break it down and make the nutrients it contains quickly available to subsequent crops.
After several years of no-till farming and keeping the residue carbon-nitrogen ratio in balance, Bauer says tests show the organic content of his soils has increased from a range of one to three per cent when he started zero tilling to three to five per cent last season. Along with better and faster nutrient cycling, the soil has an increased ability to retain moisture.
Nichols says there are environmental factors that can slow down the rate of residue decomposition, but microorganisms are able to work even in less than ideal conditions, such as cold soil temperatures. In fact, tests showing how much activity goes on in even frozen soils have surprised her. So farmers should continue to focus on soil health to maximize the rate of decomposition regardless of the weather in a given year. “You have to address the system as a whole,” she says.
But soil microorganisms may not quickly break down all residues no matter what producers try. New Bt crop varieties of corn and other glyphosate resistant crops have affected the ability of microorganisms to break down their residue. “It’s because they’re not the same,” says Clapperton. “What we had was a bunch of organisms that were adapted to a particular crop. Now the organisms are behind, they need to adapt (to new GM varieties) to break that residue down.” Unfortunately, there is little anyone can do to speed up that process. Farmers just have to wait for nature to catch up.
Having a healthy soil with a diversity of microorganisms can also limit the danger to crops from pests, says Clapperton. “Predator prey relationships are the key to this,” she says.
Reducing pesticide applications offers a potential reduction in input costs. “Some of those things (pesticides) are really nasty things. We need to ask ourselves if we need them,” she continues. “Every chemical we use comes with some risk. We need to take time and plan for the system before we decide if we really need them. We need to find a balance.”
The big attraction for farmers willing to change their mindset and manage for a whole-systems approach is significantly improved profit margins. However, the period of transition could be financially difficult.
“There is that transition time going into no till,” says Nicols. “Farming is always going to have peaks and valleys, but when you get into working with the biological system, those peaks and valleys aren’t as sharp. But I know you’re going to have economic difficulties at the start.
However, that initial pain may be well worth the gain. “Usually people who have been in no-till — depending on their rotation, and that’s a very important consideration — in eight to ten years they start to see they can actually get away with less (inputs),” says Clapperton. How much less depends a great deal on individual farm circumstances. “Some organic growers in Saskatchewan went 20 years before running into phosphorus depletion,” she says.
“Some farmers I know hardly use any nitrogen at all; they might just use pop-up P and N. They have hardly any inputs and their bottom line is significantly higher up. They’re definitely doing more with less, and not destroying their soils. They’re not mining (nutrients).”
“What I’m suggesting is there are reserves from all the stuff (fertilizer) we’ve used before. We need to pull it up and start using it.”
ScottGarveyismachineryeditorfor Grainews.Contacthimatscott. [email protected]