PERDUE and KINDERSLEY, Sask. – With concerns about high nitrogen fertilizer prices, low commodity prices and early season moisture conditions, some producers have been trying to hedge their input risk.
They have been applying only a
basic fertility program, then topping up their fertilizer when the crop is up if moisture conditions improve.
Research by Guy Lafond at Indian Head, Sask., found that when rainfall was favourable, topdressing a portion of nitrogen was quite effective. However, in drier years, the results from topdressing nitrogen were disappointing.
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Research by John Harapiak, a former chief agronomist at Westco, found that when the growing season rainfall was average or better, applying one-third of the nitrogen in the seed row and topdressing the rest as granular urea at the tillering stage was almost as effective as preplant banding all the required nitrogen. But in the absence of post-seeding rainfall, topdressing nitrogen was relatively ineffective.
Researchers have suggested the following guidelines for the portion of nitrogen applied at seeding: at least 60 percent in low rainfall regions; at least 40 percent in moderate rainfall regions and 20 percent in favourable rainfall regions.
Assumptions for these guidelines include:
- Normal early growing season rainfall.
- Topdressed nitrogen applied no later than the early tillering stage.
- Adequate rainfall to move topdressed nitrogen into rooting zone within two weeks of application.
- Fields have been adequately fertilized with nitrogen for the past 10 years.
- The topdressed fertilizer nitrogen is treated with a stabilizer.
In west-central Saskatchewan, at least two fertilizer retailers have been working with farmers to help manage their fertility programs using split
nitrogen application programs.
Rack Petroleum at Perdue uses granular urea treated with Agrotain, while G-Mac’s Agteam at Kindersley has been topdressing with liquid fertilizer.
“Some guys have been doing it if they’re trying to reduce their risk, in terms of not being sure what the year’s going to bring,” said Gaylord Dennis, location manager and certified crop adviser for Rack Petroleum in Perdue.
“They may not want to put all their eggs in one basket, so they may just put down a light rate of seed-placed fertilizer for pop-up. If conditions look more promising and they think the yield potential is there, they go out and topdress the crop.”
In spring 2002, when some farmers in the area were seeding cereals, Dennis said their outlook was grim. They put down a pop-up fertilizer, then it rained and they topdressed.
“When topdressing a crop, the first thing you figure out for your rate depends on your target yield. Then you have to decide what fertilizer you use – sulfur fines, a mix of fines and urea, or if you’re just going with straight urea, you have to top it up with some kind of stabilizer to keep it from gassing off. All those factors will help you decide what amount to put on. Your yield target, moisture conditions, help you decide,” he said.
“Most guys like to go out at the four-leaf stage of the cereal. That gives them yield and protein. If you go after the five leaf, that will still give you a protein boost. Some guys go earlier for yield and protein, while others just go after protein.”
Rack also topdresses canola. It could be done as a risk management tool, because the producer’s seeding equipment or time limit how much fertilizer can go on at seeding.
“If a guy is seeding canola with a narrow opener and is restricted as to what he can put down with the seed, we’ll top dress with sulfur fines. We’ll do that anytime between emergence and bolting,” said Dennis.
“The cost for the application includes the product being hauled to the farm and being put onto the ground. That frees up a little time for the farmer. He can maybe put down a 65 pound blend with the seed instead of 150 or 200 lb., which slows up his seeding progress.”
Dennis said there are times when he’ll broadcast urea before the farmer seeds his crop. Because the nitrogen in urea is at risk to gassing off if it’s not incorporated into the soil, Rack often uses the nitrogen stabilizer Agrotain.
“If a customer wants 700 acres floated on, what we might do is not put on any Agrotain for the first field, then put our rates different. There’s a five day, 10 day and 15 day rate, so we might go to different rates, depending on how quickly he’s going to get to that field to cover it up,” said Dennis.
“But unless it’s late fall or winter, we usually put Agrotain on urea. The worst situation is on a light textured soil, with no Agrotain on it, to get a tenth of (an inch of) rain followed by a heavy-duty wind, there’d be quite the losses.
“If we’re using a urea-sulfur mixture, what I’ll do is treat just the urea with Agrotain, but not the sulfur. That keeps it from going into the atmosphere.”
Dennis said hayland and pasture are also starting to get more fertilizer attention from farmers.
“A lot of guys are starting to notice their hay stands are getting weak. Some of these stands are over 20 years old. With crops, you’re putting nutrients back into the soil with the straw coming out the back of the combine. With a hay crop, every ounce of foliage that gets cut is taken off that field and none is replaced,” he said.
“We’ve had remarkable success with older stands, with a mix of sulfur fines, nitrogen and even potash, in some cases doubling the yield. We’ve had some pastures where they haven’t had enough cattle in there after we’ve topdressed. The growth has increased so much they need more cattle in to use it up before it gets too coarse.”
Rack uses Loral granular applicators with 75 foot booms to topdress. Tender trucks haul the product from the plants to the floaters, to keep the floaters in the field.
“You can easily get 600 to 700 acres a day done with one machine. With the flotation tires, you can get out under conditions where you can’t go with a tillage type piece of machinery.”
At G-Mac’s Agteam in Kindersley, Chris Cox said the company has expanded its topdressing program since experiencing the dry conditions of five or six years ago.
“We didn’t put much on the first three or four years. They’d put their blend down and it didn’t rain, so we didn’t do much at all because it was so dry. The last few years, we’ve been putting lots on,” said Cox, business operations manager.
“We try to put enough fertilizer down for a 25 to 30 bushel crop. If it rains, we shoot for the 40 to 50 plus yield.”
With cereals, Cox might add 30 to 35 lb. of actual nitrogen, or up to 50 in extreme cases. He uses strictly liquid product, with nitrogen and sulfur.
“We try to get it all on before the six-leaf stage in cereals and before bolting on canola. As it goes later, there’s more protein benefits and less yield benefits in cereals.”
G-Mac’s uses an 1844 Terragator that has solid-stream nozzles on 10 inch spacing, plus a Rogator equipped with three-stream nozzles on a six inch spacing.
“That’s what most farmers would probably use. Then we have two 60-foot dribble bars equipped with 10 inch spacing,” said Cox.
“Fertilizer prices are higher than they have been in a long time, which forced some guys to cut back a little bit, but now seeing the moisture, some guys are topping it up more than they were planning on because of the moisture conditions.”
Cox added that with labour an issue, sometimes it’s worth it if farmers can’t find extra help and would like to seed longer without stopping to fill with fertilizer.
“Getting us to do it is a way of reducing their workload a bit too.”
One of G-Mac’s customers is the Springfield Colony north of Kindersley. Ike Kleinsasser, field manager with the colony, said 2006 will be the third year he has done topdressing.
“It leaves you open so if it starts raining you can get a little better yield and protein. With canola, if you’re a little deficient, you can go in and correct it,” said Kleinsasser.
“You don’t have to put all your money out at seeding time. If it stops raining, you don’t do it, but if you get moisture, you go out and do it. We put enough for a good average crop, but with last year and this year it seems good, so you go out and topdress.”
Kleinsasser said in his area, durum and canola take about the same nitrogen, you just have to work harder with the sulfur on the canola. In 2005, he started with 40 lb. of nitrogen and about 2.5 lb. of sulfur on Kyle durum, then topdressed with 25 lb. of nitrogen and four lb. of sulfur.
“Right now (2006), we’re going to go about 35 N, with about five to seven lb. an acre of sulfur as a liquid. The best time would be the three to five leaf stage, but if there’s a rain, it might not go on at the best time,” he said.
“We’re working with Agri-Trend and they were out and said you can do it right up to flowering on the canola and you’ll still get the benefit. With durum, we go up to the flag leaf, but I wouldn’t want to go much past it.”
The colony uses its own high clearance sprayer to topdress crops, using banding nozzles on the boom.
Kleinsasser said in his experience, having the pressure down around 30 psi means less leaf burn.
“But with the big cabbage leaves on the canola, Agri-Trend said upping the pressure there might be beneficial. Pushing it down faster would help it go past the leaf. We’ll try that this year on our canola, upping the pressure a touch. But on the durum, you get a little burn but it’s not an issue at all.”
