The Canola Council of Canada (CCC) wants to see growers utilizing 4R nutrient stewardship practices on 90 per cent of canola acres by 2025.
“We have found there is a strong appetite for this from NGOs, and some food companies that have sustainability metrics and want to source sustainably produced products,” says Curtis Rempel, vice-president of crop production for CCC. “And, based on a 2016 survey, there was a fair amount of awareness among growers [of 4R]. We decided, based on the outcomes, the appetite and the fact that we can build a good knowledge and technology transfer base, that we’d like to have 90 per cent of our acres enrolled [in 4R by 2025].”
The 4R goal is one of the recent updates to CCC’s sustainability goals that also include reducing fuel use by 18 per cent, sequestering five million more tonnes of greenhouse gas emissions annually in Canadian soils, and increasing land use efficiency by decreasing the amount of land needed to grow one tonne of canola by 40 per cent.
Canola growers have already made big strides toward sustainability, using conservation tillage and innovations in crop protection and nutrient management to help sequester 11 million tonnes of GHG in their fields every year, while also preserving organic matter and moisture in soils and preventing soil erosion.
According to a 2016 national survey of farmers’ fertilizer management practices, 3.2 million acres were grown with awareness of 4R nutrient stewardship, and 78 per cent of farmers surveyed were aware of 4R.
The internationally-recognized 4R Nutrient Stewardship Program outlines best management practices for the responsible use of plant nutrients, such as nitrogen fertilizers.
The 4R nutrient stewardship principles are the same worldwide, but locally adapted to different soils, cropping and management systems and climate. The science-based principles of 4R are right source, right rate, right time and right placement.
Right source ensures a balance of essential nutrients taking into account naturally available sources and fertilizer product characteristics. Right rate means fertilizer decisions are based on soil nutrient supply and plant demand. Right time is based on the dynamics of crop nutrient uptake, soil supply, potential nutrient losses and the logistics of field operations. Right place addresses root-soil dynamics, nutrient movement and variability in the field to meet crop needs and limit nutrient losses.
The benefits of 4R
Some of the major international organizations supporting 4R nutrient stewardship like the World Health Organization and the Food and Agricultural Organization of the United Nations are concerned about global issues, such as food security, reducing greenhouse gasemissions and sequestering carbon dioxide to address climate change. There is recognition that agriculture can play a huge role in mitigating these issues.
“Many scientists are stating that the most impactful way to reduce CO2 emissions is by intensifying agricultural production and using plants to pull CO2 out [of the air] and turn the CO2 into healthy food — oil, protein and fiber,” says Rempel.
Although increasing agricultural intensification is good for carbon sequestration, the big question is how to do that without increasing damage to soils, water and air quality through increased pesticide, fertilizer and fuel use?
“We have a number of ecological footprint measurements that we tie to our strategic plan and they make the argument that the canola industry and canola producers can reduce CO2 emissions and achieve our target of 52 bushels per acre by implementing a sustainability plan that leaves our soil, air and water in better shape. A big part of that is 4R nutrient stewardship, which applies not just to fertilizer but also to pesticides.”
Higher crop yields require more fertilizer, however the key, says Rempel, is to be used by the plant and not running off, mineralizing or volatilizing into non-target sources.
“That also allows the canola our producers grow to have more access to more markets, by ensuring the consumer that we’re producing food in a sustainable fashion,” says Rempel.
At the farm level, the 4R approach has been proven to provide tangible economic returns for canola growers by providing higher yields with more targeted inputs.
“Fertilizer is the No. 1 cost for a canola grower, so 4R is about paying attention to what rates you’re going to use. Are you going to side-band your starter phosphorus [P] in such a way that you’re not damaging your seed so that you’re getting all of the canola seed that you planted emerging?” says Rempel. “Are you applying your N at a time when it’s stable in the soil and readily available to the plant, or applying a N stabilizer product to reduce N loss? All of those things produce more dollars in growers’ pockets.”
Three ways to get started with 4R
One of the easiest places to start implementing a 4R program — that doesn’t involve a large amount of money but gives an immediate return on investment — is (1) regular soil testing, (2) setting realistic yield targets, and (3) choosing the right canola hybrid based on that data.
“Our top canola growers are doing all of those things,” says Rempel.
As far as placement and rates, Mario Tenuta, professor of soil ecology at the University of Manitoba, has conducted a number of canola studies looking at these things, specifically for N fertilizer, from both an agronomic standpoint in terms of yields, and also the environmental benefits, such as reduction of N losses to the environment in terms of nitrous oxide (N2O) and CO2 emissions.
Recommended N rates vary depending on location, moisture, canola hybrid and yield potential, but it’s common for farmers growing new high-yielding hybrids to be using N rates of 110 to 120 pounds per acre or higher. That represents a high cost for farmers and a higher risk of N losses to the environment, so it’s understandable that farmers would look at 4R to see if they can improve the efficiency of the fertilizer they use and drive yield without negative ecological impacts.
A major project compared three N placement options using conventional, granular urea – broadcast, a shallow mid-row band (3/4 inch to one-inch deep) and a deep mid-row band (2-1/2 to three inches deep) and the use of N inhibitor products like SUPERU.
“Without inhibiting nitrification, we got more N2O emissions, but whenever we added a product that slows down nitrification, we got a reduction in N2O emissions,” says Tenuta.
He also found that subsurface placement of N resulted in a reduction of ammonia volatilization. “With the deep placement of 2.5 inches, no ammonia was detected being emitted from the soil,” says Tenuta. “With the shallow band at around .75 inches we found a little bit, but not much. But we found more ammonia, which is not surprising, being emitted when the granules of urea were left at the surface of the soil. If we added Agrotain (a urease inhibitor) to the broadcast fertilizer, we saw lower volatilization losses of ammonia.”
Tenuta also tested N application rates and placement to see the effect on yield, comparing a zero-rate control and 70 per cent and 100 per cent of the recommended rate based on Manitoba provincial soil test guidelines. As expected, Tenuta saw no difference in the 100 per cent treatments, but at 70 per cent the subsurface placement produced several more bushels per acre yield on average.
There is still more research needed on how these enhanced efficiency products work under the cold weather conditions of Western Canada.
“There’s not a win every time, but growers may want to start thinking about them and ask their agricultural retailer lots of questions,” says Rempel. “Does it make sense for me? Can you show me real-world data in Western Canada done with randomized, replicated trials that show that this would beneficial for my farm?”
Tenuta has just begun a project into in-season N application in canola comparing different placements and rates of UAN (urea ammonium nitrate), and using UAV’s and handheld sensors to predict in-season N rates.
“One of the advantages of doing an application in-season is that you’re delaying your N application and you can actually see how much nitrogen you need,” says Tenuta. “It’s best to ask the crop what it needs, so we’re trying to do that with these sensors. That’s our current evolution in the 4Rs.”
Moving to the next level with 4R
One of the challenges for many producers in adopting a complete 4R nutrient management strategy is fertilizer placement.
“Placement is a challenging issue because of the demand for getting the fields planted and fertilized in a short window, and an easy way of getting the job done is to float and surface broadcast,” says Tenuta. “We have demonstrated that subsurface placement (banding) provides yield benefits but there are practical considerations to be able to do that, especially when you are dealing with a small-seeded crop like canola. If you’re disturbing the soil, it might disturb the seed bed, so you have to band the fertilizer further away from the seed.”
Placement also often drives the need to change seeding equipment, which growers might not be ready to invest in.
“We’re saying that 4R can be part of the continuum,” says Rempel. “When growers are ready to replace their seeder or planter, that’s the time to think about different systems.”
There are a lot of questions to answer when it comes to making capital purchases that are going to make 4R easier and more effective to implement. For example, do I want a one-pass system? What type of openers will work well for my soil and moisture conditions with a small-seeded crop like canola?
“Growers are going to want to use that implement for all of their crops, so they will likely have to make some compromises,” says Rempel. “We would argue that canola being the small-seeded crop, and very sensitive to fertilizer placement, that maybe canola should be the first focus for growers and then they compromise a little bit on some of their larger-seeded crops because they’ll probably be more flexible.”
N inhibitor and stabilization products are effective ways to help reduce environmental impact and increase yields, but the cost of these products can be a stumbling block.
“It’s a challenge to recover the premium cost of these products in increased yield alone,” says Tenuta. “In some cases, growers can recover the premium cost based on cost savings for application of the fertilizer because it allows them to broadcast it. There are other advantages to the enhanced efficiency fertilizers other than just the yields, which can affect a bottom line for a farmer.”
4R is a flexible, adaptable system
One of the benefits of 4R nutrient stewardship is that the basic principles can be adapted to suit any type of farm, soil conditions, environment and practical considerations unique to each operation.
“Different people are at different places of what they can do practically, and the beauty of 4R is it’s not a penalty program, its an enabler program,” says Rempel. “Even if last year’s harvest conspired against you, and you can’t do the right timing or something, then you can focus on the rate and product type. It’s not meant to be a penalty system; it’s meant to help you think about what are the optimal things you can do given the circumstances.”
Where to go for information about 4R
There are a lot of places where growers can go to learn about 4R principles and how to apply the best management practices to their farm.
The 4R Nutrient Stewardship website (a collaboration of the Fertilizer Institute, International plant Nutrition Institute, Fertilizer Canada and the International Fertilizer Association) has a number of downloadable resources and factsheets on many 4R topics. They include considerations for placing fertilizer with seed, split fertilizer applications, starter fertilizer, soil and pH testing considerations, N losses, soil supplements, the role of precision technology and calculating nutrient budgets.
The Canadian Roundtable for Sustainable Crops also has information about 4R as part of its sustainability metrics and sustainable agriculture alliance, Field to Market Canada offers some benchmarking tools and a Fieldprint calculator to measure the environmental impact of crop production.
The CCC offers Canadian growers many online resources, which are constantly updated with the latest research and data, such as its canola encyclopedia that, in its fertility section, outlines what the 4Rs are all about and the decision-making processes involved in implementing it.
“We also have our Canola Watch newsletter and other fact sheets that we adapt and adopt messaging from the Canadian Fertilizer Institute, and we also work with Ducks Unlimited Canada’s biologists and agronomists, as well as provincial oilseed specialists and others working on Environmental Farm Plans,” says Rempel. “There’s a number of different ways that we’re starting to get growers to understand what 4R is about.”
CCC has also adopted a new strategic approach to help achieve its sustainability goals, focusing on connecting more with retail agronomists rather than directly with growers. The Canadian Fertilizer Institute now offers a specific 4R training program. “These agronomists are going to be accredited and certified as being 4R compliant and I would strongly encourage growers to seek those practicing agronomists out,” says Rempel.
A lot of canola growers are already on the path to 4R stewardship, sometimes without even realizing it, says Rempel.
“So, part of [the message] is, you’re already doing it, but then how do you totally immerse yourself?” he says.
“If you are already in a good spot for deciding what fertilizer rates you’re going to be using, then what are the other things that you need to do to start building a plan on your farm?”
4R Nutrient Stewardship Resources:
- Canola Council of Canada – Canola Encyclopedia
- Sustainability Goals (Canola Council of Canada)
- 4R Plant Nutrition Manual (downloadable) from International Plant Nutrition Institute
- 4R Nutrient Stewardship
- 4R Pocket Guide
- Canadian Roundtable on Sustainable Crops – Nutrient Management Metrics
- Field to Market Canada