Agrium used its Ag In Motion canola plots to show visitors how ESN controlled release fertilizer can help farmers get to 100 bushels per acre.
The plan included a lot of fertilizer. “My intention was to look at growing 100 bushel canola based on crop removal rates, having high rates of phosphate, high rates of sulphur applied,” says Agrium’s agronomy specialist, Ray Dowbenko. In terms of actual nutrients, he says, “we put on 360 pounds of nitrogen, 75 pounds of phosphate, 30 pounds of potassium and 50 pounds of sulphur. We also put on a pound and a half of boron.”
For Prairie grower to meet the Canola Council of Canada’s goal of average canola yields of 52 bushels per acre, Dowbenko says, they’re going to need more fertilizer, and to consider nutrient stewardship.
But to ensure good fertilizer stewardship at these higher levels, “we’re going to have to look at split applications, or we’re going to have to look at a controlled release product such as ESN where all of the product can be put in the ground at one time, and we don’t have to be concerned about seasonal nitrogen loss.”
Dowbenko says ESN can “lower the cost per acre for growers, control the release of nitrogen, protect nitrogen loss through the season and also reduce early season vegetative growth or biomass.”
With more nitrogen, there is potential for canola crops producing more vegetative growth. “If you give a plant lots of nitrogen and lots of moisture early in the season it will grow a lot of vegetative material, and then it doesn’t have as much nitrogen left over for grain yield.” More biomass can also cause lodging and complicate harvest.
If nitrogen is released slowly, the plant can use some of it later, when it’s growing seed rather than biomass.
Water use can also be improved. “We do have studies that show by controlling the release of nitrogen early we can improve water use efficiency because we’re metering out the nitrogen so the plant is not growing great guns early in the spring and using lots of water. It’s just a bit more judicious in its water use and its vegetative growth.”
ESN is temperature and moisture driven. With soil moisture and warm soil, the urea will start to diffuse out of the plastic coating as a liquid.
For the Prairies, Dowbenko’s rule of thumb is that from application day, the first week about eight to 13 per cent of the nitrogen will be released; by the end of the second week 20 to 25 per cent will be released; by the first month between 45 and 60 per cent will be released.
With this schedule, ESN is ready when the canola needs it to produce seed. “Because it’s indeterminate it keeps setting flowers throughout the season. It’ll still take up nitrogen later. That’s why ESN has a good fit on canola — because canola will still produce yield later in the season.”
Agrium had two plots at AIM: one with straight urea, and another showcasing ESN blends. On its ESN trial plot, Agrium planned to broadcast and incorporate a 50:50 blend of ESN urea in the spring (200 pounds of actual nitrogen). Then they planned to side-band 100 pounds of nitrogen with a 70/30 ESN/urea blend.
Additional nitrogen fertilizer went on with the phosphate and the sulphur to get to 360 pounds per acre.
From a nutrient stewardship perspective, “the broadcast may not be my first choice,” Dowbenko says. But to fertilize at this level, compromise is necessary, and coated or controlled release products reduce risks of loss. “In this demonstration, we were not set up to pre-plant band our initial nitrogen application.”
Running large-scale plots for an outdoor farm show isn’t that different from running a farm. Things rarely go as planned.
As with all of the AIM plots, Agrium’s plots were not harvested before snow fell, but Agrium’s problems began before that.
Dowbenko expected the Ag In Motion staff would make that first pre-seed nitrogen application with a floater. But when no floater was available, AIM staff wound up applying nitrogen with seeding equipment as a last resort. Unfortunately, applying that much fertilizer required a lot of passes. “They really compacted the soil,” Dowbenko says.
But still, the ESN granules did what they were supposed to do. AIM visitors could dig up ESN granules in the plots during the mid-July show. Different granules were at different stages of release. Some were empty, some were squishy, and some were still hard. “Some nitrogen was still releasing; some was still available for the future,” says Dowbenko.