Craig Drury, a soil biochemist at the AAFC Harrow Research and Development Centre, is analyzing the effectiveness of nitrogen inhibitors and nitrogen placement strategies. Photo courtesy of Craig Drury.
Nitrogen inhibitors can dramatically improve productivity and injection is by far the best way to incorporate nitrogen into the soil while minimizing nitrogen loss.
These were key messages in a presentation by Craig Drury, a soil biochemist at Agriculture and Agri-Food Canada’s (AAFC) Harrow Research and Development Centre, at an Innovative Farmers Association of Ontario meeting in December 2015.
Drury is in the second phase of field studies funded by AAFC’s Agro-Ecosystems Productivity and Health Science Strategy and the 4R Nutrient Research Network (Fertilizer Canada), analyzing the effectiveness of nitrogen inhibitors and nitrogen placement strategies. The study, which is a continuation of a previous two-year study, began in 2015 and will continue until 2017.
The goals of the study are threefold – Drury’s team, which includes Dan Reynolds, Xueming Yang and Wayne Calder, first aims to analyze how much nitrogen is lost from the soil as ammonia through volatilization or as nitrous oxide through the denitrification process. Second, they are assessing the effectiveness of different fertilizer application methods and how these could reduce losses and increase nitrogen uptake by corn.
They are also examining the effectiveness of nitrogen inhibitors – Agrotain, a urease inhibitor, and Agrotain Plus or SuperU, both urease and nitrification inhibitors.
Drury says the landscape has changed in terms of nitrogen fertilizer trends in Canada. “From 1980 to 2010, nitrogen fertilizer sales in Canada increased by a factor of 2.4. The amount of nitrogen fertilizer sold and used is increasing for many reasons.”
But that’s not all that’s changed. Drury says urea and UAN together account for 74 per cent of nitrogen sales in Canada, and that figure is increasing. “Right now, about 52 per cent of the nitrogen fertilizer sold in Canada is urea and 22 per cent is UAN,” he says. “The point is that we have seen over time a greater and greater percentage of nitrogen fertilizer being applied contains urea, whether it’s all granular urea or it’s 50 per cent urea in liquid UAN.”
The problem? Much of the fertilizer added to soils in Eastern Canada is lost to the environment – a problem both for the environment and the grower’s bottom line.
Drury says that when nitrogen is added to the soil as a fertilizer, as manure, through natural atmospheric deposition or nitrogen fixation via legume plants, it undergoes natural biological and chemical conversions. To be used by the plant, nitrogen has to be converted to ammonium and/or nitrate; but ammonium can easily volatilize and be lost to the atmosphere.
Under very wet conditions, negatively charged nitrate can leach out of the root zone through tile drains or it can be converted to nitrous oxide, which is lost to the air, where ultimately it contributes to the greenhouse gas effect.
“That is a problem on many levels – your nitrogen is going into the air or out of your tiles instead of the soil or the plant, so it’s a costly loss of the applied fertilizer,” he says.
Nitrogen inhibitors can help diminish this effect by slowing the conversion of urea into ammonium, which allows more time for the nutrient to move into the soil.
Findings Drury’s study analyzed broadcast urea, UAN streaming and UAN injection, and used, in total, three separate fertilizer nitrogen sources: urea or UAN, urea or UAN plus a urease inhibitor and urea or UAN plus a urease and nitrification inhibitor.
The team used wind tunnels and air sampling instrumentation to measure ammonia losses.
The findings, so far, have been dramatic. Drury’s team found that 54 pounds per acre (lbs/ac), or roughly $3,200 for 100 acres of broadcast urea, was lost to volatilization, versus 23 lbs/ac or $1,500 for 100 acres of injected UAN.
Urease inhibitors decreased ammonia losses by 57 per cent (from 54 to 22 lbs/ac) for broadcast urea – $1,900 worth of savings for 100 acres. But even more notably, the use of urease inhibitors resulted in a whopping 97 per cent decrease in ammonia losses with the injection of UAN.
In total, Drury says, the combination of urease and a nitrification inhibitor also decreased nitrous oxide emissions by 21 per cent.
“If you have the opportunity to incorporate nitrogen into the soil through injection or immediate broadcast incorporation that’s certainly worth doing, and will get the nitrogen into the soil fast and efficiently,” he says.
But even with injection, the team still noted ammonium volatilization losses through the injection slot. “So with both broadcast urea as well as injection, it was still beneficial to include the urease inhibitor to decrease volatilization and have the nitrogen go into the crop,” Drury says.
These findings are not just about losses – Drury’s team also measured gains in yield. He says use of urease inhibitors increased yields by 5.5 bushels per acre with broadcast urea, and by 12.5 bushels per acre with the combination injected UAN. The benefit totaled $1,700 per 100 acres for broadcast urea, or $54 per acre, or $5,400 per 100 acres in the injected fields when urease inhibitors were also used.
“In all cases, it was very profitable, even when you consider the cost of the inhibitors. The revenue from the yield increase was far greater than the cost of the inhibitors,” he says.
“Clearly, there are ways of managing our fertilizers and our soils to reduce environmental losses and losses of expensive nutrients and have more of that nitrogen going to the crops and increasing yields.”
Developed by plant breeders in Saskatchewan and Manitoba during the 1960s and 1970s to meet a growing demand for edible oil production in Canada, canola has become a major cash crop in Western Canada. It has been less attractive economically for eastern producers, primarily because so few crushing facilities are located within a reasonable distance from the major growing areas in Eastern Canada.
However, that is changing. Between 2006 and 2011, canola production in Eastern Canada increased 305 per cent to more than 141,000 acres, increasing farm-gate cash receipts almost 700 per cent to $46.3 million. And the 2010 operationalization of a canola and soybean crushing plant and oil refinery in Becancour, Que., by Twin River Technologies – Enterprise de Transformation de Graines Oléagineuses (TRT-ETGO) further significantly brightens the prospects of canola production in Eastern Canada.
This growth created an urgent need for the industry to develop sound agronomic practices for canola production in Eastern Canada, particularly with respect to nitrogen fertilizer application and improved nitrogen-use efficiency, for the environmental and economic sustainability of canola production.
To address that need, Agriculture and Agri-Food Canada (AAFC) scientist Dr. Bao-Luo Ma is leading a project at the Eastern Cereal and Oilseed Research Centre (ECORC) in Ottawa, with the assistance of university professors Dr. Donald Smith and Joann Whalen from McGill University, Dr. Anne Vanasse from Laval University, Dr. Claude Caldwell from Dalhousie University and Dr. Hugh Earl from the University of Guelph, as well as Peter Scott, the provincial forage specialist for New Brunswick’s Department of Agriculture, Aquaculture and Fisheries.
Since 2011, the group has conducted experiments during the growing seasons at various sites in Eastern Canada to investigate the growth, yield and yield components of canola in response to various combinations of pre-plant and side-dressed nitrogen with soil-applied sulfur and soil and foliar-applied boron. Sites are located in Ottawa and Elora, Ont.; Ste. Anne de Bellevue and St-Augustin-de-Desmaures, Que.; Fredericton, N.B. and Canning, N.S.
At these sites, the researchers are investigating the responses of different canola cultivars (hybrids) to the timing and rate of nitrogen application, the combination of nitrogen and sulphur, nitrogen and boron, yield, nitrogen use efficiency and carbon footprints of different rotation systems – canola following wheat, soybean or corn. And, they are identifying the traits and tools for the development of nutrient cycling knowledge, implementing site-specific best management practices and adapting canola to existing cropping systems.
“Our preliminary results indicate that canola yields increased by 9.7 kilograms per hectare (kg/ha) for pre-plant nitrogen application and by 13.7 kg/ha for side-dress nitrogen application, for every kilogram of nitrogen per hectare applied, in six of the 10 site-years,” Ma says. “The challenge remains to develop site-specific fertilizer applications that deliver ample nitrogen, sulfur and boron for canola production considering that unfavourable weather conditions may cause nutrient losses and constrain canola growth at key development stages in Eastern Canada.”
Because agriculture production is a complex system, modifying one nutrient in the cropping system could have cascading effects on other nutrients and other crops as well. Developing efficient nutrient management regimes is a prerequisite for promoting canola as a viable cash crop in Eastern Canada.
“Canola is a non-legume crop and requires large amounts of nitrogen fertilizer for production,” Ma says. “Inefficient use of this nutrient not only reduces farmers’ profits, but may also put the environment at risk with nitrate nitrogen leaching, ammonia volatilization, nitrous oxide emissions, etc. affecting the air we breathe, water we drink and daily environment.”
From their research, Ma’s team have determined a number of best practices for successfully growing canola in Eastern Canada, including applying a small portion of nitrogen fertilizer at pre-sowing and the majority of the nitrogen nutrition at the five to six leaf, or bolting, stage. “This would increase canola seed yield and/or increase nitrogen use efficiency,” Ma says. “This may also give farmers the option to reduce the amount of nitrogen application when drought or other stresses are expected during the growing season.”
Other best practices are to plant the crop in narrow row spacing – seven inches – at a seeding rate of five kg/ha and, based on the long-term trend of average minimum air temperature in April and May, to determine the optimum seeding date. Optimum seeding dates usually occur the last week of April to the first week of May for Ottawa, Guelph and Montreal regions; May 11 or after for Sainte-Foy and northern Quebec region; and late May for Harrington, P.E.I.
Ma says they will continue to create and advance the knowledge and technology required to broaden canola production in Eastern Canada to meet the demand of the industry, improve producers’ competitiveness on the global market, provide consumers with healthy and environmentally friendly food and fuel and provide the general public with a continued high quality environment.
“As new cultivars are being developed, research activities are required to develop/implement site-specific and matching strategies to obtain the true potential of new cultivars in farmers’ fields,” says Ma, narrowing the gap between cultivars’ potential yield and realized yield under field conditions as an example.
Oct. 29, 2015 - In their first year of large field-scale trials in Western Canada, nitrogen stabilizers N-Serve and eNtrench proved to secure more available nitrogen for plants and in many cases, contribute positively to yield.
N-Serve and eNtrench, used with anhydrous ammonia and liquid fertilizer respectively, prevent the loss of soil-applied nitrogen to leaching or denitrification by keeping nitrogen bonded to the soil in its positive form.
Fall-applied N-Serve trial results
In 18 trials across Western Canada where N-Serve was applied with anhydrous ammonia in the fall, soil tests taken two weeks after emergence found those fields to have 81 per cent more positive ammonium available, compared to adjacent trials where only anhydrous ammonia was applied.
Why apply nitrogen with a nitrogen stabilizer in the fall?
"Two big advantages: save time and save money," says Jason Smith, market development specialist with Dow AgroSciences Canada. "You have the opportunity to get that field work done in the fall rather than spring, and take advantage of lower fall fertilizer prices.
"Many growers apply nitrogen at higher rates in the fall, understanding that they were going to lose some of that nitrogen. A product like N-Serve eNtrench is going to significantly reduce the potential for those losses and therefore keep all that nitrogen available to your plant for the next spring."
Spring-applied N-Serve and eNtrench trial results
When N-Serve and eNtrench were applied in the spring in 30 different trials across Western Canada, soil tests taken four weeks after emergence showed those fields to have 44 per cent more positive ammonia available, compared to fields with only either anhydrous ammonia or liquid fertilizer.
"Overall the field trial results have been very positive and very encouraging," Smith says. "In areas where we had good rainfall and in some cases excessive rainfall, we're seeing some fairly significant differences in yield as well."
"So overall, anecdotal results, we're seeing about 3-5 bushel yield bump where nitrogen loss is a significant factor, and in the wheat we're seeing yield bumps in that range of 5-10 bushels."
Growers interested in learning more about N-Serve and eNtrench nitrogen stabilizers and product availability should speak with their retailer, or contact their Dow AgroSciences representative. More information is also available at www.protectyournitrogen.ca.
September 30, 2015 - Ontario is working to improve and maintain water quality in the Great Lakes by supporting the development and implementation of a nutrient stewardship program for farmers.
As part of a recently signed Memorandum of Cooperation, Ontario will provide $50,000 to Fertilizer Canada and the Ontario Agri Business Association to develop educational programs for farmers about nutrient management based on the internationally-recognized 4R Nutrient Stewardship system, which promotes efficient fertilizer application to improve profitability while reducing nutrient losses.
"Canada’s fertilizer industry is encouraged by the Government of Ontario’s endorsement for 4R Nutrient Stewardship as an important tool to meet the province’s environmental stewardship goals," says Garth Whyte, president and CEO of Fertilizer Canada. "We look forward to working with the Ontario government and agri-retailers to improve practices that will ensure the sustainability of the agriculture industry while enriching the health of the Great Lakes."
Ontario's farmers have already made significant contributions as stewards of the land, completing more than 23,500 on-farm environmental improvement projects since 2005, including grass buffer strips, wind breaks, cover crops, nutrient storage and structures to prevent soil erosion. The Memorandum of Cooperation will further support the province's farmers as well as protect watershed areas and prevent algae blooms.
"Agri-retailers are well positioned to work with Ontario farmers to implement the 4R Nutrient Stewardship Program as a practical tool for enhanced environmental sustainability," states Dave Buttenham, CEO of the Ontario Agri Business Association. "The financial support and commitment by OMAFRA demonstrates the recognition within government that 4R can play a key role in achieving both environmental and farm sustainability."
The 4R Nutrient Stewardship system uses four key pillars for fertilizer application: Right Source, Right Rate, Right Time, Right Place.
On December 19, 2014, Ontario approved the new Canada-Ontario Agreement on Great Lakes Water Quality. In that agreement, both Canada and Ontario commit to creating action plans to reduce the impact of excess nutrients on the water quality of Lake Erie.
Oat is a competitive crop that is suited to central and northern Alberta growing conditions, but oat agronomic research has been lacking in Alberta in recent years.
“When I found out about the high yield potential of oat, I was fascinated by its potential to be a high-value crop for growers,” says Linda Hall, a weed scientist and agronomist at the University of Alberta.
Her excitement about oat’s potential inspired Hall to initiate a three-year project on optimizing production of food-grade (milling) oats in Alberta. She is working with Sheri Strydhorst, an agronomy research scientist at Alberta Agriculture and Forestry; Bill May, a crop management agronomist with Agriculture in Agri-Food Canada in Indian Head, Sask.; and Joseph Aidoo, a graduate student at the University of Alberta.
Based on Statistics Canada data, the average oat yield for Alberta for the past five years was 82.7 bushels per acre (3120 kilograms per hectare). This low average yield may be due in part because oat is often grown for hay and forage, rather than for grain, but also because oat is sometimes planted as a default grain crop when it’s too late to seed crops like wheat or canola. Results from variety trials and other sources show oat grain yields on the Prairies can be around 120 to 155 bushels. According to Hall, oat’s yield potential could be over 200 bushels under the cool, moist growing conditions preferred by the crop and using agronomic practices aimed at high yields.
“Although oat can be high yielding, the common variety grown in Alberta is not the best for high-value milling oats,” Hall notes. “So one objective of our project is to compare the yield of some newer high beta-glucan oat varieties. This may provide a new marketing opportunity for Alberta growers.” Food processors are interested in beta-glucan because this dietary fibre has important health benefits, such as lowering cholesterol.
“The most reasonable way to increase oat yield is to plant early and increase nitrogen fertilizer. Unfortunately, higher nitrogen tends to result in thinner seeds, which is not as good for the milling market, which prefers plump seeds with a high test weight,” she says. “So we need to find a balance – how do we maximize yield and yet still retain quality?”
Another effect of high nitrogen rates is a greater risk of lodging. Hall says, “Particularly in northern Alberta where moisture levels are usually good, when growers use higher rates of nitrogen, the crop tends to lodge, which causes harvesting problems and reduces yields. So our second objective is to determine if new plant growth regulators can improve the harvestability and standability of oat varieties.”
Plant growth regulators are synthetic compounds that modify plant growth; their effects on cereals may include shorter, stronger stems, reduced lodging and/or higher yields. Little research has been done on the use of growth regulators on oat in Canada, so Hall’s project could provide valuable insights.
The project, which started in 2014, involves two field experiments. Experiment 1 aims to evaluate the effects of nitrogen rate and oat variety on yield, lodging and beta-glucan content. In this experiment, nitrogen in the form of urea is banded at seeding. The treatments are 5, 50, 100 and 150 kg N/ha, with the amounts of the urea applications adjusted for the soil type and the amount of soil nitrogen. The experiment compares five oat varieties: AC Morgan (four to five per cent beta-glucan); OT3066 (four to five per cent beta-glucan); Stride (5.5 to six per cent beta-glucan); CDC Seabiscuit (5.5 to six per cent beta-glucan); and CDC Morrison (six to 6.5 per cent beta-glucan). In 2014, Experiment 1 was conducted at Edmonton and Barrhead, which are both in Alberta’s prime oat growing region.
Experiment 2’s objective is to assess the effects of four rates of a plant growth regulator on Stride, under the same four nitrogen treatments as in Experiment 1. The growth regulator is under
development and not yet registered for use on oat in Western Canada. The researchers chose Stride for this experiment because it showed lodging tendencies at higher nitrogen rates. In 2014, this experiment was carried out at Edmonton, Indian Head and Barrhead.
First year results
In Experiment 1 in 2014, oat yield increased as the nitrogen level increased, as expected. Hall says, “Our best yielding variety was AC Morgan, the variety used by most Alberta growers. But unfortunately Morgan had the lowest beta-glucan content of the varieties in our trial. CDC Morrison, the highest beta-glucan variety, was the lowest yielding.”
The optimal nitrogen rate for maximum oat yields varied depending on the oat variety and the location. For example, CDC Morrison’s yields were highest at the 150-kilogram rate at both locations, while AC Morgan’s yields were greatest at 50 kilograms at Edmonton and 100 kilograms at Barrhead. Higher nitrogen levels tended to decrease 1000-kernel weights and increase the percentage of thins. Also, plant height and lodging tended to increase as nitrogen increased, although there was minimal lodging at the sites in 2014. Height and lodging were variety dependent, with Stride lodging more than the other varieties.
In Experiment 2, at two of the three sites, the plant growth regulator reduced plant height and lodging. “As we increased the nitrogen, the height of Stride increased, and as we applied more plant growth regulator, we saw a reduction in height. So, by using a plant growth regulator, we were successful in counteracting the increase in height from the nitrogen,” Hall explains.
In 2014, the plant growth regulator did not affect oat yield. Hall notes, “Accurate timing is very critical for a plant growth regulator to be effective. In auxiliary experiments, we found that the growth regulator had to be applied at early stem elongation, after the herbicide application window and before fungicides are applied. To be effective, the plant growth regulator would have to be applied as a separate treatment.”
Once the project is completed, the researchers will be able to share up-to-date information on food-grade oat production with central and northern Alberta growers.
AAFC Charlottetown Research Centre Open House and TourFri Aug 04, 2017
Potato Research DayWed Aug 09, 2017
Saskatchewan Sunflower Field DayThu Aug 10, 2017 @ 1:00PM - 04:30PM
Biochar Field Tour Open HouseFri Aug 11, 2017
Mackenzie Applied Research Association Field Tours, Agriculture Fair&Trade ShowFri Aug 11, 2017 @ 9:00AM - 02:00PM
Ontario Potato Field DayThu Aug 17, 2017