While fall or early spring banding of fertilizer is a basic recommendation for optimizing nitrogen efficiency, according to soil specialists, Prairie producers use a number of different approaches to get the most value out of fertilizer dollars. In this panel, producers talk about new products and new technology they feel have helped improved overall nitrogen-use efficiency on their farms.
LEE MOATS RICETON, SASK.
A split-application of nitrogen is giving south-Saskatchewan producer Lee Moats more peace of mind. After seeing at least $20,000 worth of nitrogen sit in the ground during a very dry 2008 growing season, he likes the concept of applying a portion of fertilizer requirements at time of seeding, and then topping up a few weeks later once he has a better idea of what the growing season is like.
Moats and his wife, Laurie, crop about 2,660 acres on the Regina Plains. Last year he switched to GreenSeeker technology to apply top up nitrogen to his canola and wheat crops.
“It was such a dry spring in 2008 that it cost us a lot to have too much nitrogen in the ground,” says Moats. “If we had had GreenSeeker in 2008 during the top up application we probably wouldn’t have applied any nitrogen at all.”
Using GreenSeeker for the first time in 2009, Moats was very pleased with the results, although he admits it was only one year’s experience. He applied about 50 to 60 per cent of the required fertilizer at time of seeding, and then top dressing with nitrogen in early July. He had the highest canola yields ever and the highest durum protein levels ever. “And it appears that we produced more with less,” he says, estimating the system applied about $6,000 less in nitrogen, through the split application, than if he had placed a full recommended rate at time of seeding.
GreenSeeker was developed by NTech Industries in the United States, and adapted for use in Canada by researcher Guy Lafond with Agriculture Canada in Indian Head, Sask. It attaches to the field sprayer and uses sensors to read the chlorophyll levels — essentially the colour — of the crop. It then applies varying amounts of nitrogen to bring any less productive areas up to their full yield potential. (For more on the specifics, read Lyndsey Smith’s article on page 8.)
Moats seeds with a ConservaPak double-shoot seeding system. With canola, nitrogen and ammonium sulphate are banded to the side and phosphate is placed with the seed. With durum, nitrogen is banded to the side, and phosphate placed with the seed. With lentils, phosphate is banded to the side and only seed, treated with nitrogen-fixing inoculant, is placed with in the seed row.
A full rate of nitrogen, based on soil test recommendations, was about 80 pounds of nitrogen banded at time of seeding. With the split application system, Moats applied about 50 per cent of nitrogen at time of seeding. The 2009 growing season was cool. While there was moisture, the crop was slow. He waited as long as he could to make the call. By July 1, with a decent crop, and good prospects for rain, he made the top up application using GreenSeeker.
GreenSeeker has been calibrated for crops in different soil zones. Seeing good potential for his crop, Moats switched GreenSeeker from Brown Soil Zone algorithms to Black Soil zone algorithms. And the decision paid off.
“With canola, for example, with the split application we applied a total of 68 pounds of nitrogen. The recommended rate if I had applied everything at seeding was 80 pounds,” says Moats. “So we applied less, and still had the highest yields ever.”
JOHN BURNS KANDAHAR, SASK.
As a long-time producer near the “friendly Kandahar,” John Burns finds the delayed nitrogen release provided by Agrotain-treated urea helped to significantly improve his crop protein levels. Burns, who along with his family operate Windy Poplars Farm, tried the treatment for the first time in 2009. With one year’s experience, he’s not saying Agrotain is God’s gift to agriculture, but even with higher yielding wheat crops, protein levels were considerably better.
“Usually when you have higher yields, in that 50 to 60 bushel range, protein levels drop,” says Burns, who crops about 13,000 acres of grains and oilseeds over Dark Brown, Black and Grey Wooded soil zones. “But last year our wheat hit 14 per cent protein, and even our winter wheat hit special select grade with 11 and 12 per cent protein. In previous years we struggled to make 10 per cent protein.”
Burns credits at least part of that improved protein to the fact that as the Agrotain treatment delayed the release of nitrogen for about two weeks after seeding, the crop had a better chance of taking up nutrients when it was most needed.
Another change he made in 2009 was to use a newer form of fertilizer called S15. Available as Cargill and Simplot branded products, S15 is a blend of monoammonium phosphate (11-52-0), ammonium sulphate (21-0-0-24) and elemental sulphur, giving a combined nutrient concentration of 13-33-0-15. S15 offers the convenience of having the P and S in the same pellet with a relatively low concentration of N.
Even with side banding fertilizer, Burns feels there is a risk of seedling injury with higher rates of nitrogen. With a good plant stand in 2009, again in the first year of using Agrotain treated urea, he suspects there may have been less seedling mortality.
Using a New Holland SD (Flexi-Coil) air drill, Agrotain treated urea is banded to the side of the seed row and S15 is placed with the seed. He side bands about 70 pounds of urea with wheat and barley, and 80 pounds of urea with canola.
One other difference Burns observed in crops last year was less vegetative growth. “I think that delay in nitrogen release encouraged better seed development than vegetative growth,” he says.
Burns is also looking at the potential of using ESN, which is urea treated with a polymer coating that releases nitrogen more gradually over the growing season. It is more expensive than Agrotain, and he’s concerned about having sufficient moisture during the growing season to help release the nitrogen.
In 2010, he plans to do a 50-50 trial with ESN and Agrotain on winter wheat to see if one product is more effective than the other. And now with precision openers on the drill, he also hopes to try inter-row seeding (seeding between the stubble rows) to see if that produces a yield improvement.
PATRICK KUNZ BEISEKER, ALTA.
Using variable rate technology (VRT) to apply fertilizer to their 2,400 acres of cereals and oilseeds over the past three years has helped Patrick Kunz optimize yields and maintain a better balance of nutrients in the soil.
Kunz, who along with his parents Chris and Vreni, and brother Kevin, operate Kunz Farms, just north of Calgary, says he may not be using less fertilizer than before, but the nutrients are now being applied where they will do the most good.
Kunz produces feed barley, wheat and canola on the mixed farm that includes a 2,500-head custom feedlot and a 120-head cow/calf operation. Before switching to VRT three years ago, Kunz did regular soil testing and would apply one blend at the same rate over an entire field.
“Our main interest then was to insure fields were left with residual nitrogen of 25 to 30 pounds per acre,” says Kunz. “If we had that residual then we could be fairly sure the crop had what it needed. But in soil testing, we found some areas of the field had zero nitrogen and other areas had 200 or 300 pounds. It was ridiculous.”
Working with agronomists at their local DynAgra farm service centre in Beiseker (www.dynagra.com),he set up a VRT system to better match nutrients to the productivity potential of the soil. “If you have a crappy area in a field, it is always going to be crappy,” says Kunz. “That doesn’t mean you can’t look at ways to improve the productivity of some areas over time, but throwing more fertilizer at it doesn’t work.”
Using a combination of tools that include yield maps, soil analysis and satellite imagery known as normalized difference vegetation index (NDVI), the DynAgra agronomist can develop a fertilizer prescription for the various zones in each field. With a VRT system on the seed drill, the perscription varies nitrogen rates according to the productivity of the various zones in a field. It applies more in those areas where the soil has most yield potential, and less on the less productive sites.
Kunz seeds with a 54-foot Bourgault drill. A starter blend, that includes phosphate and potash in cereals, and sulphur and potash in canola, is seed placed, while the urea is mid-row banded. Depending on the field, there will be five to seven zones where different rates of fertilizer will be applied.
“We’re not trying to get 100 bushels of barley off every acre. We want to get 100 bushels on those sites with potential to produce 100 bushels, and if another site has potential for only 60 bushels, then we’ll fertilize for a 60 bushel yield,” he says.
Lee Hart is a field editor for Grainews in Calgary, Contact him at 403-592-1964 or by email at [email protected]