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Tips For Direct Seeding

“Loamy soils are best for direct seeding, while sandy or heavy soils may not be. But because direct seeding is a cropping system that maintains crop residue and conserves moisture, it’s the sandier, heavier soils that can benefit the most.”

In many ways, the opportunities for you to save money through direct seeding — not to mention meeting growing consumer demand for sustainable environmental practices — are greater than ever before, says AgTech manager Lawrence Papworth. Here’s a snapshot of today’s trends and what’s in the pipeline for the future.

SEED PLACEMENT RETHOUGHT

Driven largely by the system’s optimal horsepower requirements, placing seed at the same depth as fertilizer in a double-shoot operation has evolved to become the gold standard in seed placement, says Papworth. Most opener manufacturers have responded by tailoring their openers to this system. For producers still placing their fertilizer two to two-and-a-half times deeper than their seed, Papworth says equal seed and fertilizer depths represent perhaps the greatest opportunity to optimize their direct seeding systems.

— Lawrence Papworth

Improvements in seed placement accuracy have driven new crop options for producers, says Papworth, particularly for crops like canola that require placement at a shallow point in the seedbed. Floating openers, for example, have made seed placement more accurate and easier for producers to control. “Because there’s a setting on each individual shank, producers no longer have to control the depth of 40 to 50 openers with a single setting. As a result, more canola is being planted because seed can be placed at a shallower depth more easily.”

Other technologies drawing interest among producers are seed bed levelers and air diffusers. “These have become known for their improved and even seed placement, packing or soil surface leveling,” says Papworth.

Low-disturbance Cross Slot openers are also worth keeping an eye on, he says. These single-disc openers place seed and fertilizer in horizontally separated bands or “slots.”

“Cross Slot openers replace residue over the slot and trap moisture in the slot. This helps assist germination even in very dry soils,” says Papworth. “I have heard great things about the technology and am not sure why it hasn’t caught on.” (For more on Cross Slot openers, read Scott Garvey’s article starting on page 29.)

HOE VERSUS DISC OPENERS

The advantages of hoe openers come down to their cost efficiency and their ability to penetrate dry soils. Their main disadvantage is their potential for soil disturbance resulting in soil scatter and in-row weed growth.

“One solution to this is to slow down. However, this can lead to reduced field efficiencies,” Papworth says. “Another is to go to very narrow hoe openers. This is good as far as penetration and soil disturbance is concerned but it goes against the advantages of seed bed utilization.”

Disc openers, meanwhile, are associated with accurate seed placement, especially when placing oilseeds at shallow depths, says Papworth.

“Discs have the disadvantage of straw pinning into the seed bed. Solutions include disc setups such as coulters that are better at cutting residue and the development of stubble management systems.”

RESIDUE MANAGERS

The AgTech Centre recently investigated the effectiveness of residue managers and wheels while direct seeding field crops. “We determined that residue managers and wheels are viable options for use with hoe and disc openers but differences in crop emergence and yield occurred infrequently,” says Papworth.

“Two systems, the Brummelhuis Seeding System and the Siemens residue wheel, worked very well at clearing residue, allowing the seeder to operate without plugging. Unfortunately, these two systems are not commercially available.”

ALL SOIL TYPES CAN BENEFIT

Soil type is not usually an insurmountable limiting factor when it comes to the effectiveness of most openers today. “While it’s true that some openers do work better in certain types of soil, from what we’ve seen most openers will work in most soil types provided they are used and set properly,” says Papworth.

In some cases, it’s a matter of choosing the right equipment, he says.

For example, an air seeder is better suited to wet soil areas. Air

“If farmers have a seeder on a 12-inch spacing and they’re growing a heavy enough crop that they need that 12-inch spacing to clear the residue, then the system’s alright. But if the yield isn’t high enough, I would suggest going to a narrower row spacing.”

seeders don’t pack soil directly over the seed, but in wet soil, the seed is likely to germinate regardless of whether soil has been packed around it.

The bottom line is that producers shouldn’t rule out the switch to direct seeding because of soil type. “Loamy soils are best for direct seeding, while sandy or heavy soils may not be. But because direct seeding is a cropping system that maintains crop residue and conserves moisture, it’s the sandier, heavier soils that can benefit the most.”

NEW NUTRIENT OPTIONS

As long as producers have wallets with bottoms, there will always be a demand for less expensive nutrient sources or systems that can stretch the value of existing nutrients. Although most are in their niche stages right now, Papworth says new technologies in the pipeline may offer potential for producers to get more bang for their nutrient buck.

Biochar is one such option. This process involves heating straw in an oxygen-free tank until it becomes coal, then applying it to the soil as a supplement once every five years. It then systemically leaches into the soil over time. Another is the new wave of anhydrous ammonia meters, such as Exactrix, whose manufacturers claim can meter product more accurately, saving producers money in the process.

Perhaps the most potentially controversial new system is Bio-

Agtive Emissions Technology. The manufacturers claim this system recycles machinery exhaust emissions into soil-injectable plant nutrients. Going by what he has heard from researchers and producers, Papworth says opinion on the system in the research community varies greatly while most farmers experimenting with the system are taking a cautious approach.

WEED CONTROL

One of the biggest challenges of direct seeding, particularly for producers putting the practice in place for the first time, is weeds. Not surprisingly, then, weed control continues to be a focal point

ROW SPACING REMAINS CONTROVERSIAL

The question of whether to use narrow or wide spacing between rows continues to be a source of controversy among researchers. For Papworth, the question comes down to which system allows the best seed bed utilization. “When you use a wide row spacing, seed placement can be compromised and that can mean reduced yields. That’s why I generally suggest narrow row spacing to producers.”

However, there are cases where

— Lawrence Papworth

in direct seeding related research.

In many cases, weed management in direct seeding systems requires being open-minded to new management practices, says

Papworth. For example, probably the best way to control dandelions — one of the most common weeds producers experience when direct seeding — is to spray after fall harvest before winter freeze-up. “This method allows you to kill the weeds with the pesticides going into the roots,” says Papworth. wider row spacings are appropriate. “One of the big reasons wider row spacing came about was so seeders could clear crop residue,” he says. “If farmers have a seeder on a 12-inch spacing and they’re growing a heavy enough crop that they need that 12-inch spacing to clear the residue, then the system’s alright. But if the yield isn’t high enough, I would suggest going to a narrower row spacing.”

A nine-inch spacing is a good compromise that allows seeders to clear residue without spacing too wide, says Papworth. “You can put a little wider opener on that kind of system and in the process increase your seed bed utilization,” he says.

Other ongoing areas of controversy include the debate over in-row versus between-row fertilizer placement and the ideal seed to fertilizer placement. Ultimately, these are individual management decisions relating to specific farms and systems, says Papworth. “If it doesn’t rain, it doesn’t matter which system you use.

“Cost of energy is another factor — power input requirements might outweigh a potential yield response from optimum seed and fertilizer placement and row spacing.”

BE FLEXIBLE WITH ROW WIDTH

AgTech research has revealed that, in most cases, increasing row width leads to an increase in yield. Again, seed bed utilization is the key here, says Papworth, as wider rows generally lead to better use of the soil and its nutrients.

At the same time, it’s important to be flexible when it comes to row width in order to grow different crops and respond to market conditions. “Some crops, like canola, call for more narrow seed rows. You wouldn’t want to use a four-inch row when planting canola because wider rows mean that you have to place the seed deep enough that the soil flows around the opener. That means it’s usually too deep for canola, which demands more shallow seed placement.”

CROP ROTATIONS

Most producers are learning that carefully planned crop rotations go hand-in-hand with direct seeding, says Papworth. Without the option of tillage to manage crop residue, the potential for a crop to contract disease increases dramatically. Producers’ key tool for fighting this problem in a no-till, direct seeding system is crop rotations combined with pre-seeding burnoff and, if necessary, in-crop chemical application.

Cereal on cereal rotations are generally not effective in a direct seeding system because disease can carry over from one cereal crop to another, says Papworth. A more suitable crop rotation for direct seeding would be a cereal with an oilseed or a pulse. In that case, volunteers would be easier to handle and disease is less likely to be carried over.

CHEAPER DIRECT SEEDING

The cost of direct seeding systems can be intimidating, especially for producers putting the practice in place for the first time. One budget friendly option, says Papworth, is the Technotill packer. Technotill uses a burr located directly behind the opener instead of a separate wheel for packing, making it ideal for seeding into wet soils. But perhaps the most attractive feature, he says, is the bang for your buck.

“It’s a lot cheaper way of getting into direct seeding than buying an air drill. You can take an old chisel plough, put a set of Technotill packers on it and you have a tool for direct seeding. It can easily save $30,000 to $40,000 compared to the price of a new air drill.”

AgTech Centre, part of Alberta Agriculture and Rural Development’s Technology and Innovation Branch, is in Lethbridge.

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