NH₃ Applications – Ways to Ensure Seed and Fertilizer Separation

For producers who work with NH₃ the benefits far outweigh the extra concerns. Many farmers in Canada and the U.S. have discovered the advantages of putting down NH₃ at seeding, but the process comes with a few hitches—like extra attention to detail and mandatory adherence to safety procedures.

Working with NH₃ is a careful process that requires vigilance and extra attention to detail.

"The key factor is separation of seed and NH₃, which is usually recommended to be between 2 and 3 inches. Seeding depth is recommended to be between 1 and 2 inches," says Extension Agriculture Engineer Vern Hoffman at North Dakota State University at Fargo. "Placing the NH₃ at that depth means equipment begins to pull harder, which may require a bigger tractor."

With all fertilizers, separation between the seed and fertilizer is necessary to prevent burn or toxicity, which ultimately leads to a thin crop. "With ammonia, separation is even more important than with other products because ammonia expands when it hits the soil," explains Hoffman.

The trick is to have a seeding system that allows for consistent horizontal or lateral separation of the seed from the fertilizer.

"Never put ammonia directly under the seed in a one-pass seeding system. There has to be lateral separation for seed safety," says Norm Flore, Westco account manager with the Saskatchewan Wheat Pool in Calgary, Alberta. "Westco has ammonia detection kits available through their retailers that allow growers to quickly assess the placement of ammonia relative to the seed in the soil."

Loss Prevention

The ammonia must also be retained or trapped in the soil immediately after application. "If ammonia is lost from the soil then it occurs immediately at injection. If there is no evidence of loss at the time of application, such as excessive white puffing or strong ammonia odors, then growers can be confident that ammonia is sealed in the soil," says Flore.

When applying NH₃, growers must take into consideration the kind of soil they are seeding into and their particular openers. "Soil tilth (aggregation, bulk density, porosity, structure) can greatly affect the success of application," says Flore. "It's important to choose the right system for your conditions."

There are three main types of air seeding application systems. "Interrow or mid-row banding places the fertilizer in between the seedrows and offers the greatest safety," says Flore. "Ample distance between the seed and ammonia gives you seed safety in the widest range of possible soil conditions."

Sideband, bolt-on openers apply seed and fertilizer in a one-pass operation. Generally, sideband openers place the fertilizer 1 inch deeper and 1 inch to the side, although that varies with system. Flore notes that in most cases these openers work well, but should be monitored for seed and fertilizer separation if soil conditions become adverse.

Paired-row Openers

A fairly wide paired row at least 3 to 4 inches apart is recommended to ensure lateral separation from the ammonia.

"Many growers have used these openers with great success, but they require attention to detail," says Flore. "They are the least forgiving in adverse soil conditions."

More attention should be paid to separation with both sideband and paired-row openers. For example, the openers can start out working perfectly at the beginning of the seeding operation, but if soils are drier or wetter three weeks later, the same level of separation might not be achieved. The point is to check and recheck separation as conditions change during seeding.

"Also, check openers for wear," says Flore. "New openers and worn openers provide different levels of separation. Check the openers behind the tractor wheels first because they wear the most rapidly due to the extra compaction." Hoffman points out: "Although NH3 is the cheapest cost per pound of nitrogen, some growers get discouraged by the safety hazards," he says. Training is an important component; it shouldn't be overlooked. To increase safe use and handling, keep equipment in good condition, follow safe handling and application recommendations and take safety training. These measures will help growers lower the costs of an N fertilizer application and at the same time maximize yields and profitability.

Worn openers reduce seed placement accuracy.

Growers Discover Real-time NH₃ Cost Benefits

"The number one advantage of NH₃ is cost-effectiveness," says Westco's Norm Flore. "It's not uncommon for NH₃ to be 5 cents or more per pound cheaper than liquid or dry fertilizer. For some farm operations, this can equate to savings of $10,000 or more on nitrogen fertilizer per year."

Extension Agriculture Engineer Vern Hoffman says putting seed and fertilizer down in one-pass reduces the cost of production. "Producers are taking advantage of this benefit. We're seeing a lot of growers in North Dakota move to air seeding. Today almost 70 percent of the crops are seeded with air seeders."

Hoffman says that the type of seeding system varies from zero-till and minimal disturbance applications to higher disturbance seeding systems with sweeps, for example. "The big advantage with air seeding technology is that growers can do a much better job of depth control at the time of seeding, which is important to ensure a good stand and to get the seed into moist soil."

He points out that growers no longer have to do a tillage operation prior to seeding, which only dries out the soil to the tillage depth and reduces the amount of available soil moisture at seeding.

Agri-retailer service is another reason many producers take advantage of NH₃. "Dealers will usually bring the NH₃ out to the field, which saves a lot of time, labor costs, and wear and tear on equipment," Flore points out. "Ammonia is also a lot less product to handle. For a given nitrogen rate, farmers require only one-third as much product compared to liquid nitrogen fertilizer."

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