“Research has shown there is a five to 10-year transition period, during which the soil ecosystem adjusts to no-till management,” Stevens said. “During that time, no-till fields may require higher inputs and/or produce lower yields compared to conventional practices.”
In the Nesson Valley study results, yields for corn, soybean, sugar beet and barley have not been substantially reduced by no-till systems so far, but some inputs like fertilizer and labor have been lowered.
In the short-term, however, there is a learning curve and there are substantive management issues to sort out. | READ MORE
Despite efforts to reduce phosphorus levels in freshwater lakes in North America, phosphorus loads to lakes such as Lake Erie are still increasing, resulting in harmful algal blooms. This has led to increased pressure to reduce phosphorus from non-point sources such as agriculture.
While no-till has long been touted for its ability to reduce phosphorus (P) losses in field run-off by minimizing the amount of phosphorus leaving farm fields attached to soil particles, recent research raised concerns that phosphorus levels in tile drainage from no-till fields were higher than from conventionally tilled fields.
A group of long-time no-till farmers, called the ANSWERS group, wanted to see if this was the case on their own farms under their management practices. The farmers approached the government and researchers in order to set up a scientific study.
Funding came from Environment Canada’s Lake Simcoe Clean-Up Fund, the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), the Agricultural Adaptation Council’s Farm Innovation Fund and the Grain Farmers of Ontario. “It was a collaboration between researchers, farmers and government,” says Merrin Macrae, a researcher from the University of Waterloo. Macrae was involved in the project, along with Ivan O’Halloran, University of Guelph (Ridgetown), and Mike English, Wilfrid Laurier University.
The results were good news for farmers who have adopted no-till. There were no significant differences in the P losses between any of the tillage treatments, Macrae says.
The multiple-site, multiple-year project took place from 2011 to 2014 on farm fields near St. Marys and Innisfil under a corn-soybean-wheat rotation. A modified no-till system had been in place at both locations for several years prior to the study. This system is a predominantly no-till system but with some shallow tillage at one point during the three-year crop rotation, for example, following winter wheat. This tillage system is referred to in the study as reduced till (RT); the other two tillage systems in the comparison were strict no-till (NT) and annual disk till (AT) treatments.
Tile water was monitored for three years for each of the tillage treatments. The tile drains were intercepted at the field edge (below ground) to capture edge-of-field losses at each study plot. Discrete water samples were collected from each tile using automated water samplers triggered by tile run-off. The weather was also monitored.
Tillage type did not affect either the dissolved reactive phosphorus (DRP) or total phosphorus (TP) concentrations or loads in tile drainage. Both run-off and phosphorus export were episodic across all plots and most annual losses occurred during a few key events under heavy precipitation and snow melt events during the fall, winter and early spring, Macrae explains. The study shows the importance of crop management practices, especially during the non-growing season, she says.
Both tile drainage flow and phosphorus losses were lower than the researchers expected, Macrae says. Previous studies suggested about 40 per cent of precipitation leaves cropland in tile lines but in this study that proportion was significantly lower.
Macrae admits the researchers were surprised there wasn’t more dissolved phosphorus in the tile drainage water from the NT and RT sites due to the increased presence of macropores and worm holes. However, she points out that these farmers also use best management practices (BMPs) for phosphorus application in addition to using a reduced tillage system. For example, the farmers apply only the amount of phosphorus that the crop will remove. The phosphorus fertilizer is also banded below the surface instead of being surface-applied.
Macrae believes soil type also plays a role in the amount of dissolved phosphorus leaving farm fields in tile lines. “These sites were not on clay soils,” she says. “Clay soils are more prone to cracking, which could lead to higher phosphorus concentrations in tile lines.”
The research highlights the importance of bundling BMPs, Macrae emphasizes. “It’s not just tillage. Farmers should adopt a 4R’s approach: right source, right rate, right time, right place.”
Macrae also says farmers should do what they can to ensure nutrients stay in place, such as maintaining good soil health, using grassed waterways, riparian buffer strips and water and sediment control basins (WASCoBs) where needed, and carefully choosing when and how to apply nutrients.
“Since most of the water movement occurred during the non-growing season, the study showed the importance of how fields are left in winter and why it is important to not spread manure in winter,” she says.
The variability of rainfall intensity, duration and timing will also impact phosphorus losses, she adds.
In future, Macrae hopes to study the impact of tillage on phosphorus losses from clay soils as well as the impact of other management practices such as manure application and cover crops.
Ben Rosser, the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) corn industry program lead, has a few ideas for changing that.
Rosser just wrapped up a two-year project developing a simple one-pass spring strip-tillage system with the ultimate goal of maintaining corn yields while reducing erosion in Ontario fields.
“Strip tillage offers a middle ground between conventional tillage and no-till,” he says. “Some guys don’t like no-till, because it might take too long to get out in the fields in a wet spring and plant. Strip tillage only works the part of the field that you’re going to plant. It leaves everything else untouched.”
Some early commercial designs became available in the 1980s, but interest has been relatively limited in Ontario until lately.
Rosser took over from former corn industry lead Greg Stewart last October. He says the project was a long-time interest of Stewart’s, who believed once a few barriers had been eliminated, more growers might be attracted to strip tillage.
Modern technology has made strip tillage more attractive. With GPS guidance systems, the planter can stay on the strips, and with the potential to deliver full season nitrogen (N) fertility with newer, physically protected forms of N such as Environmentally Smart Nitrogen (ESN), strip tillage may increase efficiency relative to having to return to sidedress, Rosser says.
The study utilized a six-row Dawn Pluribus Strip Tiller mounted to a Yetter caddy cart with a Gandy Orbit-Air dry fertilizer box. In 2014, fertilizer was mixed between the coulters, but in 2015 Rosser included side band tubes, which delivered one-third of the fertilizer in a band to the outside edge of the coulter.
In 2015, six separate trials were performed at farms in Arthur, Belwood, Bornholm, Elora, Paris and Woodstock. A seventh looked at contour strip tillage near Belwood to develop guidance lines that would precisely follow the variations in the field.
Rosser’s key research concerns were evaluating the yield response of strip tillage versus conventional tillage or zero tillage and the yield impact of moving phosphorus (P) and potassium (K) fertility treatments off the planter and on to the strip tiller. He also examined the safety of using urea or ESN blends through the strip tiller as a way to meet full-season N requirements.
Benefits and drawbacks
After two years the study showed strip tillage did not offer a yield benefit on any of the six sites, although data suggests there might be a yield benefit for medium to heavy soil types. But neither did the strip tillage yields show a decrease compared to those of no-till or conventional systems.
The 2014 Field Crop Report for OMAFRA on the study offers an economical reading of the data from the trial, compared with conventional systems, which Rosser carried into the 2015 report. “One might argue that the elimination of other tillage practices is made possible ($35/acre); one broadcast application of fertilizer is eliminated ($12/acre), and a sidedress application of N may also be eliminated ($15/acre),” it reads.
In addition, it continues, the planter does not require any special conservation tillage modifications and does not need to apply fertilizer, which could represent savings of $5/acre. The strip tillage operation, if applying fertilizer, can be estimated to cost $25/acre, so potential, overall cost reductions are estimated at $42/acre.
But the biggest benefit, says Rosser, is the reduction in erosion — with strip tillage, only a third of the field is disturbed.
Wes Hart, who grows corn, soy and wheat just north of Woodstock, was a farmer co-operator for both years of the study.
“I joined the study because I’d been interested in strip tillage for a while, and I’d just come into running our farm,” he says.
“One of the main things I was interested in with Ben’s system is that I wanted him to use my fertilizer in his strip till. We used my package in the strips, and we didn’t lose anything. The main difference is that there’s another pass on the field with a separate machine, but sometimes that’s worth it.”
The chief benefit of the system, for Hart, was the ability to put fertilizer down through the strip tiller. “That’s one of the holdups of my current setup,” he says.
Inspired by the study, Hart built a fertilizer banding rig that is “virtually a strip till piece of equipment.”
Rosser says a key benefit for the producer of using a strip tillage system — beyond erosion control — is the reduced number of passes over the field. But strip tillage is still more management intensive than conventional tillage, he says, because producers have to carefully plan when to hit their strips. “You have to match up strip and planter pass closely,” he says. “If you wait too long to plant, the ground may get too hard. This means more management, which might hold a farmer back relative to costs.
“If you feel you can manage that, our data suggests that strip tillage can be fairly competitive to conventional tillage.”
Yvonne Lawley, a professor of agronomy and cropping systems at the University of Manitoba, is leading the project. She initiated this research in part because many growers have been asking about vertical tillage but very little research information is available on the technology under Prairie conditions.
Another factor driving her interest in the project is the potential for expanding the corn acres in Manitoba. “A lot of the seed companies are actively working on early season corn,” she says. “I think residue management is one of the biggest challenges potentially hindering new adopters of corn. So it seemed very timely to have a project focused on the new tools available to manage corn residue in Manitoba.”
Lawley describes some of the difficulties that Prairie growers can face in managing corn residues. “In a short-season area, farmers are concerned about colder [spring] soil temperatures and wetter soils when they have lots of residue covering the soil surface. Those concerns may not be unique to corn residue, but may be aggravated by the amount of residue that you get from corn.
“Corn residue has a very high carbon to nitrogen ratio [so] it is very slow to decompose, and corn crops generate twice the amount of residue [compared to crops like soybean and wheat], especially with higher yielding corn varieties. Growers also have to deal with the shape and nature of the root balls that come with corn stalks.”
She adds, “In Manitoba, corn is often harvested at a time of year when there could be snow in the fields. Then after harvest, there’s the work of incorporating that residue, when your field may be frozen and it will likely be wet. So there are all kinds of challenges to doing residue management at that time of the year.”
According to Lawley, Manitoba growers commonly manage their corn residues using a double disc in the fall, with two or three passes to chop up and incorporate the residues. “That is expensive in terms of time and fuel. Given the very late window for corn harvest in Manitoba, time is probably more limiting than the fuel,” she says.
“I think that everyone is looking for a residue management option where they can cover more land quickly, and that is the appeal of vertical tillage – you can drive the tillage equipment fast.”
Comparing tillage treatments
The project, which started in fall 2014, is comparing four tillage treatments for managing corn residues: vertical till-low disturbance, vertical till-high disturbance, strip till and double discing, the conventional treatment as a control.
The term vertical tillage can sometimes mean different things to different people. For the purposes of this project, Lawley defines a vertical tillage unit as: “tillage equipment that has cutting discs to create vertical cuts into the soil. Those discs can run perfectly vertical or they can be angled to create more disruptive tillage. Also, at the end of the unit, there’s a smoothing or finishing component, such as rolling baskets or heavier tines, that then smooths out the seedbed.”
“In the project, we distinguish between two vertical till treatments,” explains Patrick Walther, Lawley’s graduate student who is working on this project. “In the vertical till-low disturbance treatment, the discs are at a zero-degree angle. In the vertical till-high disturbance treatment, the discs are at a slight angle, around six degrees, or we have used a unit with a slightly concave shape to the disc.” The high-disturbance treatment may also be known as a high-speed disc.
The low-disturbance treatment leaves a lot of residue on the soil surface, so it offers soil conservation advantages. The high-disturbance treatment results in a black seedbed similar to that produced by a double disc. In Manitoba, high-disturbance vertical till is more common than low disturbance. Lawley says, “Very few Manitoba farmers are using vertical tillage in a soil conservation sense. Most people are using this equipment as a high-speed disc, as an alternative to a double disc, especially with corn residue.”
The strip tillage treatment involves tilling only the strips where the seed rows will be planted. Walther notes, “With strip tillage, usually less than 30 per cent of the field gets worked, so about two-thirds of the field is undisturbed like no-till.” Although strip till is not widely used in Manitoba, he says it is common just south of the border in Minnesota and North Dakota.
“The vertical tillage and double disc treatments are more similar to each other, while strip tillage is almost like an entirely different type of tillage system,” explains Lawley. “Many farmers think strip tillage is very slow. But I think strip tillage offers some interesting comparisons in terms of giving you the best of both worlds from a soil conservation standpoint. Much of the field is protected from erosion by the crop residue cover, but early in the season, the worked strip where you’ll be planting the seed will be blacker, fluffier, drier and warmer, and all those things we’re trying to do by working the entire field.”
One component of the project involves evaluating the performance of the tillage equipment used in the project. For this component, Lawley and Walther collaborated with the Prairie Agricultural Machinery Institute (PAMI) in Portage la Prairie. They measured fuel consumption, horsepower requirements, draft force (the force required to pull the implement through the soil) and the time it takes to complete the tillage.
A key factor in the comparison is the number of tillage passes that growers typically use. “For strip tillage, we’re assuming the strips are created in one pass. For the vertical till, most farmers that we’ve talked to are using two or even three passes. With the double disc, they are usually using two passes,” Lawley notes.
For example, the tests showed that one pass with a vertical till unit takes much less time than one pass with a double disc or one pass with a strip tillage unit. However, when you consider a complete tillage operation, strip tillage takes the least amount of time because it involves only one pass. The next fastest is vertical tillage with two fast passes, and then the double disc with two slower passes.
Similarly, strip tillage has the lowest fuel consumption. “If we look at a complete tillage system, then strip till uses about three times less fuel than a vertical till system, mainly because vertical till is a two-pass system and strip till is a one-pass system,” Walther says.
Walther also took slow motion videos of the different pieces of equipment moving through a field. He and Lawley examined the videos to get a better understanding of how each tillage tool works.
“In the vertical till-low disturbance, we don’t have a lot of incorporation of crop residue. It is mainly chopping up the residue into smaller pieces. In the vertical till-high disturbance, the soil gets thrown up and mixes with the residue. In the low disturbance, there’s limited horizontal soil movement,” explains Walther.
“The project’s strip till unit tends to push the residue away from the strip and then work the soil. So it doesn’t actually incorporate a whole lot of residue,” he notes. Lawley adds, “The strip tillage is really the most intensive tillage; it is just concentrated in a very small band.”
The different tillage implements run at different soil depths. “Usually, for the vertical till-low disturbance treatment, we set the equipment to about 2.75 inches, or seven centimetres, deep. The vertical till-high disturbance unit would be about the same or a little shallower, maybe two to 2.5 inches [five or six centimetres], depending a bit on the farmer’s preferences,” says Walther. “The disc treatment is about four inches (10 centimetres) deep. For the strip till, it’s just one shank that goes into the soil, and it goes about seven to eight inches (or 20 centimetres) deep.”
Field trials, results so far
The project’s other component involves on-farm field trials in Manitoba to assess how the tillage treatments affect the following soybean crop. In 2014-15, there were two sites, one at Winkler and the other at MacGregor. In 2015-16, one site is again at MacGregor, and one is at Haywood.
The plots are field-length strips. The tillage treatments are carried out in the fall, if possible, or in the spring. Depending on the farmer’s preferences, the soybean plots may be land rolled. “Farmers in Manitoba are doing land rolling when they plant soybeans, usually just after planting, to aid in harvesting where they might have uneven ground or stones that could get caught in the combine at harvest,” Lawley says.
Walther is collecting data on soybean emergence, timing of flowering, plant height, pod height and crop yield. He is also monitoring soil temperature and soil moisture at five and 30 centimetres deep in the soybean plots throughout the growing season. As well, he will be calculating the economic costs and benefits of the different treatments.
Walther has already analyzed much of the data collected in the soybean plots in 2015. The results showed that factors like crop yield and emergence varied little between the different tillage treatments.
The average soil temperatures were very similar for all the tillage treatments. However, the temperature range from day to night varied with the treatment; the strip till plots had the warmest daytime temperatures and the coldest night temperatures. But after the land rolling operation, that diurnal fluctuation was reduced.
“We think that one of the reasons why strip till is able to warm the soil faster is due to the shape of the soil surface. A berm is created in that strip, and we think the rapid warming is driven by the ability of that berm to catch solar radiation. Then when we roll the strip, we flatten out that berm so less warming occurs,” Lawley says.
Lawley and Walther are hoping to further evaluate the effect of land rolling during the project, but that will depend on whether any of the co-operating farmers decide to do land rolling.
Walther is also collecting data for his economic analysis. He explains that an overall economic analysis will likely be challenging because there is not a lot of western Canadian data for vertical till units and strip till units regarding purchase costs, maintenance costs, depreciation and so on. Lawley adds, “People tell us that vertical till units are more expensive to maintain; the units just have a lot more bearings and moving parts.”
Better information for growers
Rather than trying to come up with one perfect system for managing corn residue, the project aims to provide data about equipment performance, crop growth, yield, soil temperature and soil moisture that will help growers make their own decisions about which tillage tool would be best for their own situation.
“Tillage is very farm-specific; it comes down to things like how people want to spread their work loads, what kind of seedbed they want to create, what kind of planting equipment they have, and what crops are in their rotation. I think this project will help farmers in Manitoba because it will give them some data by which they can weigh their options,” explains Lawley.
“Certainly the work we did with PAMI will help growers. I don’t think that type of data really exists [anywhere else] in Western Canada right now. The information about fuel consumption and travel time could help growers evaluate their own operations and different investments that they are thinking about making.”
Given that the soybean yields in 2015 were about the same no matter which tillage treatment was applied, Walther speculates that the project might also generate information that would support reducing the number of tillage passes used to manage corn residues, as long as farmers have seeding equipment that can handle planting into residue. Fewer tillage passes would reduce the time and money spent on tillage, while improving soil conservation. He points out that Manitoba has had some serious incidents with blowing soil in recent years, especially in years with dry springs.
This project is being funded by the Manitoba Corn Growers Association, Western Grains Research Foundation, and under Growing Forward 2, through Manitoba’s Agri-Food Research and Development Initiative. Lawley and Walther also thank the collaborating farmers: the Toews family at MacGregor and Haywood, Randy Froese in Winkler, and Brent Wiebe in MacGregor.
Data collected during long-term research trials at Agriculture and Agri-Food Canada’s Elora and Ridgetown research facilities continues to provide researchers with invaluable information about the complexities of crop rotations and their impact on crops.
The long-term trials, conducted between 1982 and 2012, focused on increasing the efficiency of production and reducing the environmental impact of corn and soybean production in Ontario. They revealed that long-term corn-soybean rotations, the most widely used rotations in the province, are vulnerable to moisture extremes and are associated with reduced soil organic matter leading to poor soil quality and the lowest average yields.
A new four-year study at the University of Guelph, initiated in June 2014, is building on those results to look deeper into the effect weather has on crop system resilience over time. Using yield and weather data obtained from the long-term rotation and tillage trial in Elora, the researchers tested whether crop rotation diversity is associated with greater yield stability when abnormal weather conditions occur.
“The use of more diversified rotations has been advocated as a solution to sustainably increase the long-term resilience and productivity of Ontario field cropping systems,” says Bill Deen, the research lead and an associate professor with the department of plant agriculture at the university.
Using parametric and non-parametric approaches, Deen, along with Dave Hooker from the Ridgetown campus and Amelie Gaudin from the University of California, Davis, is examining how rotation complexity in tillage and no-tillage systems alters the amount of soil water available to plants, the ability of the corn and soybean to use the water resources and the effect imposed drought stress has on yields.
Preliminary results indicate that crop diversity increases corn and soybean yields over time, lowers the risk of crop failure and mitigates yield loss due to hot and dry conditions. They also show that yield benefits of crop diversity are less pronounced in wet and cool weather and that rotation diversity decreases soybean yield variability in abnormal years with hot-dry or cool-wet conditions.
“Our preliminary conclusions reveal that diverse crop rotations do indeed add diversity to a system and that by adding some diversity, such as wheat to a corn-soybean rotation, we can reduce drought effects induced by climate change, poor soil quality and high yield potential,” Deen says. He explains the research will help identify management practices instrumental to adapting Ontario’s most abundant cropping system to changes in climate. “It will also improve productivity and water use efficiencies under an increasingly challenging environment.”
The study is attempting to further understand how including winter wheat in a corn-soybean rotation, with or without red clover, impacts water availability in tilled and no-till systems. This understanding will lead to better predictions of the future value of rotation diversification.
The researchers also believe that the value of rotation diversity is currently underestimated and that its value could increase in the future. Under a changing climate where higher frequency of excess moisture or drought is predicted, water availability could be a larger constraint on the system in the future. Independent of climate change, as average corn yield increases, demand for water by the plant will increase and the role of rotation diversity in enhancing water supply could also increase.
Finally, residue removal from simple rotations could accentuate drought responses in simple rotations and increase the value of rotation diversity. Increasing understanding of rotation diversity should lead producers to reassess the use of simple corn-soybean rotations. This can increase average per acre corn and soybean yields, stabilize corn and soybean yields when weather extremes occur and increase soil carbon and quality.
In addition to improvements in average yields and stabilization of yield, previous studies using these long-term trials have demonstrated that rotation diversity increases soil carbon and quality and also results in increased nutrient and energy use efficiency of corn and soybean production. While not yet measured, it is probable that rotation diversity will also reduce offsite movement of nutrients from corn and soybean fields by improving water and soil retention in the system.
Many producers believe that a corn-soybean rotation is still more profitable than rotations that include wheat with or without red clover. Deen and Hooker’s research provides evidence that suggests the contrary is true.
“Adding wheat into a corn-soybean rotation increased corn yield two to six per cent and soybean yield nine to 14 per cent,” Deen says. “There is also a substantial reduction in a producer’s nitrogen requirements.”
Although the magnitude of rotation benefits varied with crops, weather patterns and tillage, yield stability significantly increased when corn and soybean were integrated into more diverse rotations. Introducing small grains into short corn-soybean rotation was enough to provide substantial benefits on long-term soybean yields and their stability while the effects on corn were mostly associated with the temporal niche provided by small grains for under-seeded red clover or alfalfa.
Crop diversification strategies also increased the probability of harnessing favourable growing conditions while decreasing the risk of crop failure. In hot and dry years, diversification of corn-soybean rotations and reduced tillage increased yield by seven per cent and 22 per cent for corn and soybean respectively.
“Simple rotations have a lower probability of high yields, a higher probability of low yields and are particularly susceptible to low yields under hot dry conditions,” Deen says.
This research supports the practice of using more diversified rotations as a solution to sustainably increase the long-term resilience and productivity of corn-soybean cropping systems.
Deen says over the next two years, the researchers hope to look at the effect moisture has over the span of a year by imposing three different moisture regimes – ambient, moisture replete and drought. In this way, they will exclude rainfall and irrigate so they can compare their results to ambient conditions within one year.
“We are applying these moisture treatments to continuous corn, corn-soybean, corn-soybean-wheat (red clover) and corn-alfalfa rotations,” Deen says. “From these treatments, we will measure soil properties, soil moisture, plant response using various measurements and, obviously, yield.
“This will conclusively demonstrate the effect of rotation under different moisture regimes.”
May 16, 2016 - Seeding in Manitoba is estimated at 61 per cent complete, with cooler temperatures and precipitation in the form of snow and rain slowing progress over the past week.
Temperatures below 0 C were recorded throughout the weekend. Frost injury symptoms are evident on emerged crops such as canola, soybeans and corn. However, in some areas minimal crop injury is reported, largely in part due to very little crop emergence. Crops continue to emerge; however, slow emergence and growth was noted due to the cooler air and soil temperatures, as well as drier soil conditions in some areas.
May 3, 2016 - Alberta producers enter the 2016 crop production season with many of the same questions and concerns as last year and maybe more so.
According to the province's first crop report of the season, precipitation last fall provided some soil moisture replenishment following the dry conditions of 2015 but amounts were generally insufficient to recharge the subsoil layer. A warm, dry winter resulted in little snow cover to seal the soil and provide some early moisture for the crop to use. The snow was quick to leave in March providing the opportunity for an early start to seeding for those who could take advantage.
Seeding is off to another faster than average start with 21 per cent of the province seeded versus 27 per cent last year. The five year average for this date is nine per cent and the long term average is 15 per cent.
Approximately three per cent of crops have emerged. Soil moisture is a huge concern in all regions. Producers have slowed or delayed seeding of shallow seeded crops such as canola, in hopes of receiving additional precipitation.
This past year, Ontario saw a huge swing away from no-till to conventional or minimal tillage, according to Horst Bohner, soybean specialist for Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). The problem? Maize residues are impacting soybean yields in the following year – or so producers believe.
In 2014, the province had a late fall, followed by a cold hard winter with little thawing, followed by a very dry spring. “That led to a tremendous amount of corn residue in the spring of 2015, and then on top of that, we had a frost on May 23, and if you have a lot of residue on the surface frost does a lot more damage,” Bohner says.
And as of 2015, “every other field is black in Perth County,” he says. “In Ontario, we’re very frustrated with corn residue and quickly going away from no-till.”
The cultural change has been underway for a number of years. Back in 2008, Bohner, in co-operation with the University of Guelph, was already analyzing different tillage and residue removal treatments. He’d observed that many growers were shifting back to intensive tillage due to the belief that maize residues hindered soybean performance. Bohner’s work interested Michael Vanhie, a masters student under the supervision of Bill Deen, an associate professor at the University of Guelph, who decided to focus his research on soybean response to the management of crop residues.
Over the course of two growing seasons, Vanhie – now a field development representative for DuPont – set up a field experiment in three commercial fields to test the response of soybeans to maize residue management.
The experiment was set up to analyze three rates of removal: no removal, intermediate removal of residue (some residue, including stalks and leaves, removed), and nearly complete removal of residue (removal of as much residue as possible without disturbing the soil). The study involved 10 tillage systems and stalk chop treatments across all levels of residue removal.
The team also examined the effects of various planter types. They used a no-till planter drill in some subplot treatments, and a no-till row unit planter in others.
The results? Shallow fall and/or spring tillage did not result in higher soybean yields compared to no-till alone.
“The no-till system was one of the most competitive systems,” Vanhie says.
But there were other noteworthy results. For example, Vanhie’s team utilized a stalk chopper to try to speed decomposition of residues in one subplot treatment. When soybeans were planted using a drill planter in no-till fields after residues had been stalk-chopped, yields decreased.
“It resulted in more residue on the soil surface with a thicker mat. As you went through with the drill to plant, it wasn’t as capable of pushing the residue aside and there was a shallower seeding depth,” says Vanhie. When the row unit planter was used, however, there was no yield hit, as it was capable of manipulating the chopped mat of residue.
Year to year differences
Vanhie says that the benefits of zero tillage have been thoroughly documented; no-till results in reduced fossil fuel consumption and erosion. In most cases, he says, research has shown that no-till results in either higher yields or no yield reduction, meaning that growers usually see higher profits by using no-till.
“In our study, no-till yielded numerically better than most systems,” he says. “But there are many, many factors that affect yield – moisture, soil type and genetics, for example, and these can all have an impact on a yield response.”
Vanhie’s study involved medium-textured soils and moderate weather conditions. “When you see a no-till yield hit it is usually in a wet year where the soil is slow to warm up, and on heavy clay soils where you have poor drainage. That’s where you’d have a benefit to tilling the soil,” he says.
Bohner agrees. “How big of an issue corn residue is going to be is highly dependent on the growing season, and during those years of the project, the corn residue was not as big of an issue as we thought it might be.”
But the biggest influence on producers’ cultural practices is not research at all, but other producers’ opinions about what works.
“You can have all the research in the world to show that no-till works and yields just as much, but if there’s a feeling in the countryside that conventional tillage is more robust and yields better, people will go back to tillage wholesale and they don’t really count research as high on their list as what the neighbour is doing,” Bohner says.
OMAFRA’s recommendations are tailored to this reality. These days, OMAFRA recommends producers leave at least 30 per cent residues undisturbed on the soil surface to reduce the risk of erosion – in effect, reverting to minimal tillage instead of intensive tillage.
Bohner says residue management will be key in the years to come as corn residue biomass continues to increase. Corn yields are much higher than they were in the past, he says, while bean yields are relatively low. “Nobody wants soil erosion, and we all have to work on reducing that. One of the ways is minimal tillage versus plowing.
“You have to get a good crop, so some form of residue management is becoming more important in modern soybean
May 2, 2016 - Favourable weather and field conditions have allowed seeding operations to get underway in many areas of Manitoba.
According to the first crop report of the season, provincially it is estimated 10 per cent of the 2016 crop has been seeded. Most seeding progress is reported in the southwest and central regions.
A range of soil moisture conditions exists across the province. There are localized areas throughout the regions still experiencing wet conditions and need continued warm dry weather to dry out fields, with other areas noting drier topsoil conditions.
Winter cereal crops overwintered very well with crop conditions rated as good to excellent. Pasture and hay fields have resumed growth.
Soil, air, water, and wildlife that share the land with agricultural production are all impacted by soil management. National Soil Conservation Week, which runs from April 17 to 23, is focusing on the importance of proper land stewardship for the benefit of all resources - especially soil - under our care.
"Canadian farmers realize in order to operate sustainably for the benefit of future generations, soil, air, water and wildlife need to be cared for properly," says Paul Thoroughgood, Soil Conservation Council of Canada (SCCC) chair. "Soil conservation is much more than making the land we farm more productive," adds Thoroughgood. "Producers see their farms as directly linked with issues such as greenhouse gas emissions, carbon sequestration, water quality, air quality and biodiversity."
Led by SCCC, National Soil Conservation Week is an annual effort to put the spotlight on the continuing success in soil management while at the same time keeping soil health top-of-mind for both farmers and the public.
SCCC's Summit on Canadian Soil Health in December 2015, outlined the views, issues and challenges that farmers, scientists and industry face in soil conservation and health. Results from the Summit clearly made the case that more work is needed in Canada to support the intensification of agriculture in a sustainable way as world food demand grows.
"We want Canada to be a world leader in using sustainable management practices and production systems that ensure our agricultural landscapes continue to produce food, fibre and other products in the best manner possible," says SCCC vice-chair, Alan Kruszel. "Sustainable agriculture is dependent on good soil conservation practices. Environmentally responsible food production should be everyone's priority and ultimately starts with the soil."
To celebrate National Soil Conservation Week, SCCC is launching a photo contest that focuses on the themes of soil, water, air and biodiversity as they relate to healthy agricultural landscapes in Canada. The contest aims to show Canadians what farming sustainably in this country really looks like. For more information, visit www.soilcc.ca.
Glenlea Research Station at the University of Manitoba is home to several long-term systems-level research studies. Photo by Julienne Isaacs.
According to Don Flaten, a professor in the department of soil science at the University of Manitoba (U of M), when new research data from one of U of M’s long-term studies is published, word quickly spreads to his colleagues around the world. “Before long, they’re calling to say, ‘Don, why didn’t you tell us about this data sooner?’” he says.
Data from long-term research studies becomes exponentially valuable over time, but such studies are becoming rarer – particularly when they operate at the systems level, analyzing a variety of qualities in the agricultural system, and their interactions, over time.
“Studies like these are always under pressure because they consume resources,” says Martin Entz, a professor in the U of M’s plant sciences department, and head of Glenlea Research Station’s 24-year long-term organic and conventional cropping study. “When times get tough, they’re on the chopping block.”
Flaten says universities are especially challenged to maintain long-term trials. He leads the National Centre for Livestock and the Environment’s (NCLE’s) long-term manure and crop management field laboratory at Glenlea. “Our study has no permanent technical support,” he says. “It relies on year-to-year funding from granting agencies. Agriculture and Agri-Food Canada’s (AAFC) support for long-term studies is vital.”
The project also relies on local industry partnerships with the Manitoba Pork Council and the Dairy Farmers of Manitoba, and a variety of national and provincial grants.
Glenlea is home to several long-term systems-level research studies, including Entz’ study, which began in 1992, and is Canada’s oldest evaluation of organic cropping systems. But Entz says there are even older studies across Canada, such as AAFC’s long-term crop rotation study based at Indian Head Research Farm, which has been running since 1958. Lethbridge is also home to a very simple rotation study (not systems-based) that has been running since 1911.
“These studies are national treasures, producing amazing results that we’d never expect,” Entz says.
According to Christine Rawluk, NCLE’s research development coordinator, long-term systems-level research studies are important because systems are incredibly complex and change over time. “If you make a decision based on a short-term study, you don’t know if the change you’re implementing has true benefits or negative consequences in the long-term,” she says. “Time is a really important part of the system itself.”
Systems are vulnerable to a wide range of factors, such as weather and soil variability, and management practices.
NCLE’s manure and crop management study analyzes the effects of different types of manure fertilizer on soil nutrients over time. “One year or even three years doesn’t give you the whole picture, particularly with nitrogen, because the yields don’t start showing an effect from solid manures before five years or more,” Rawluk says. “So if we were to look at it for just one growing season, we wouldn’t have an accurate sense of how organic reserves of soil nitrogen are becoming available over repeated years.”
Flaten says farmers take a long-term approach to farming by applying specific management practices over extended periods, so it only makes sense to analyze practices in the long-term at the research level. These studies can account for the impact of short-term practices in the long term. “And sometimes there are results you don’t understand, which challenges us to realize there’s more to systems than we know,” he says.
Entz says his long-term study has paid off in spades. “One of the things we’ve discovered is that the more ecological farming systems that use fewer external inputs over time, with small adjustments to management, have become very productive and economically and biologically efficient. We’d never have discovered that if we’d only done that for five years,” he says.
The Glenlea studies have a highly practical element. Researchers actively encourage involvement from industry groups and producers so they can influence the studies from the ground up.
NCLE’s studies aim to encourage partnerships between crop and livestock producers. “We’re looking for opportunities to capitalize on the integration of livestock and cropland,” Rawluk says. “Whether it’s a mixed operation or a situation where your neighbour has annual crops where you’re applying your manure, we’re looking for opportunities for collaboration at the farm level.”
There’s another key benefit to Glenlea’s long-term systems-level research studies: they actively encourage interdisciplinary conversations and cross-departmental collaboration, which counteracts a culture of specialization that has actually been counterproductive to agricultural research.
Long-term systems-level studies are designed to be sustainable, which means seeking input from experts across the university. “When considering parameters for the Glenlea study, we consulted with economists, soil scientists, entomologists,” Entz says.
“Specialization has become the norm, and agriculture is no different – we have specialists in particular areas of soil fertility, and in plant diseases,” he notes. “You’d be surprised how difficult it is for those specialists to talk to each other. But the farm system is not specialized – what happens in one part affects the other parts. That specialization has precipitated very specialized research. Everyone is solving a problem their own way. But at some point you have to put it all together.”
Flaten calls long-term systems-level studies “goldmines” of data for agricultural research. Entz agrees. “The systems-level approach to long-term studies is valuable because life works at the systems level,” he says.
Feb. 17, 2016 - The University of Saskatchewan's annual Soils and Crops Workshop is a two day event offering updates on current research being conducted in the areas of soils, crops and economics by researchers, faculty and graduate students from across Western Canada.
The workshop is being held March 15 and 16 at Prairieland Park in Saskatoon. The first day will see a range of presentations covering crop development and crop protection, soil management, and soil biology and fertility.
The second day offers a workshop based on "pests and pulses" with invited presentations designed to provide in-depth training on a variety of topics emphasizing agronomy.
For more information and to register, visit http://www.usask.ca/soilsncrops/
More and more producers are starting to recognize the benefits forages provide in terms of improved soil quality and reduced erosion, notes Jack Kyle, the pasture and forage specialist at the Ontario Ministry of Agriculture, Food and Rural Affairs.
But, Kyle notes, “there are still many who don’t manage their forages to the optimum.”
The main – and significant – benefits of forages to the crops that follow is in added organic matter and improved soil tilth. However, Kyle warns that perennial forages must be managed correctly for benefits to be fully realized. “A well-fertilized relatively young stand of forage can be very productive,” he says. “But if there is limited fertility or the stand is old, you will not see optimal results.”
Kyle suggests new varieties of annual and perennial ryegrass may be of particular interest to growers because these species are higher in energy than the other cool season grasses and therefore make excellent forage and pasture.
While the challenge in the past has been winter survival, he says, newer cultivars and blends of cultivars are showing not only better persistence, but also higher growing season productivity.
“Rye grasses prefer a cool moist climate,” Kyle notes, “but through breeding and selection, there are now blends that are doing well in Ontario.”
Another species that is relatively new is festulolium, a hybrid forage grass developed by crossing Meadow Fescue or Tall Fescue with perennial ryegrass or Italian ryegrass, which Kyle says can be used where
ryegrass might also be considered.
Matt Anderson, manager of product development at DLF Pickseed Canada, says festulolium combines the best properties of the two types of grass. “The fescues contribute qualities such as high dry matter yield, resistance to cold, drought tolerance and persistence, while ryegrass is characterized by rapid establishment, good spring growth, good digestibility, sugar content and palatability,” he notes. “The individual festulolium varieties contain various combinations of these qualities, but all are substantially higher-yielding than their parent lines.” DLF Pickseed has developed a substantial breeding program in festulolium that has produced a unique range of varieties.
On the legume side, Kyle says there is currently quite a bit of interest in sainfoin, in Western Canada anyway, because a new higher-yielding variety called AC Mountainview was recently developed in Lethbridge, Alta., by Agriculture and Agri-Food Canada (AAFC) scientist Surya Acharya. “There is a renewed interest in grazing and wanting to maximize the productivity of the pastures,” Kyle says. “Alfalfa is excellent from a forage productivity standpoint but the risk of bloat in grazing livestock discourages its use. However, sainfoin is non-bloating, and if you include it in a mix, its non-bloat characteristics would counteract the bloat-inducing qualities of the alfalfa.”
Sainfoin (from French words “sain” and “foin” meaning “healthy hay”) is a centuries-old forage from Europe and western Asia. The plant contains a fair amount of condensed tannins, which help a cow’s digestive tract more efficiently process plant protein, preventing build-up of gas in the rumen (bloating). AAFC trials are ongoing in western provinces and may take place in Ontario in future.
Forage cultivation – fertilize and think short-term
“I think one of the biggest mistakes with forage management is the lack of fertility applied to fields,” Kyle notes. “There is a significant amount of phosphorus and potassium leaving a hay field with each harvest. Often this is not replaced with commercial fertilizer or manure. Over a few years, the fertility in the soil is reduced, resulting in reduced plant vigour and shortened stand life.” Grass hay fields and grass pastures specifically, he says, need adequate nitrogen for good plant growth and productivity.
Kyle says most forage fields reach their peak production in the third year and then productivity starts to make a significant decline, yet producers often look for five to 10 years from a forage stand. Shortening the life of the stand to two or three years instead, he advises, will result in increased productivity and the positive impact on the succeeding crops will be maximized. Anderson completely agrees.
“In pastures, the biggest opportunity to increase productivity is to rotationally graze the pastures so that the forage plants get grazed over a short time period (a few days) and then give them sufficient time to recover and regrow,” Kyle notes. “Pasture fields should be managed in the same way as hay fields – harvest at the opportune time as quickly as possible and stay out of the field until there is sufficient growth to harvest again.”
Double crop forages
Double crop forages are forages that follow a cereal crop and are allowed to grow from mid-late summer through to a killing frost in the fall. With this scenario there is going to be ground cover during much of that time, Kyle explains. “This is what forages are all about – adding organic material to the soil through ground cover and also through root growth,” he says. “It reduces soil erosion and provides improved yields in succeeding crops. And the combination of ground cover and added soil organic matter provided by double crop forages is similar to what perennial forages provide, but on an annual basis.”
When planning double cropping with forages, Kyle advises a close look at the growth characteristics of the species that you are considering in the forage mix. “Find out whether or not the species will set seed in the fall, and if so, ask yourself if you can you manage it as a volunteer next year,” he says. “The same goes for any species that might over-winter – how are you going to control it next spring?”
Kyle also urges growers to ask themselves if there is a sufficient growing season for the species to gain reasonable root and top growth, and whether or not they wish to harvest some of this crop as forage. “If yes, what considerations will be necessary given that harvest is going to occur at a time when drying conditions are poor and frequent rains may well be occurring?” he asks.
Also ask if it makes sense to pasture the cover crop. “I think this is a real opportunity for cover crop utilization,” Kyle says. “By grazing, the nutrients stay in the field, you don’t have to deal with harvest issues and you have a very low-cost livestock feed, with added benefits to the soil. It’s a win all around.”
Manitoba grain farmer and winery owner Grant Rigby wants some answers about salinity. Rigby farms is a fourth-generation 1882 homestead on the rolling Waskada clay-loam soils of southwest Manitoba, near the town of Killarney. With a University of Manitoba degree in agronomy and a master's degree in food science, Rigby hopes to find those answers.
"We produced big yields in the 1980s and 1990s," he says. "Then I started noticing a decline in productivity. White salts started showing up for the first time ever in very small patches near sloughs where the crops had been lush; they had lodged there most years."
Rigby saw compaction where the tractor drove close around sloughs. As well, he began seeing stunted crops in higher rings around sloughs. By 2000, Rigby started making changes to how he did things, and by 2002, he was done with most industry-approved approaches.
"We decided to solve it ourselves. I got rid of heavy equipment and all herbicides. I also quit using ionic chemical fertilizer, to get on board the organic marketing opportunity," he recalls.
While he notes those efforts helped, they didn't answer his question – where did the salinity come from? Today he's still working on that.
Along highways and fields on the Prairies, he says, it is typical to see "several acres per mile" where salinity has moved in. For the worst bare patches, he notes it will be extremely costly, if not impossible, to recover production. No domesticated crop species will thrive in these areas. Almost always, they are low areas with the best and deepest topsoil.
"On my farm, we were starting to get bare patches where no crops grew. There were a few spots where white salts were crystallized on the surface. Those no longer exist on my farm. I did it by letting weeds grow. I let biology thrive there," he says.
Standard practice for countering salinity is to plant deep-rooted perennial forage, usually alfalfa, to extract water from below and suck the salts down with it. "I did plant alfalfa and clover. Where they didn't grow, fortunately the salinity was not so advanced that other wild species couldn't survive. Foxtail barley and kochia invaded the bare spots. They lived where no domesticated species would, and they saved my farm from the bare spots we see on many other farms in the neighbourhood now," Rigby says.
"Quackgrass and dandelion started growing under the foxtail barley and kochia, so I added alfalfa. Now I grow hay in those patches, and I can now plant annual crops there, but I don't try to eradicate all the wild species," he adds. For example, if he suppresses the alfalfa and quackgrass with shallow discing and spiking, he can establish annual fababean or flax. "The perennials recover, but I get some grain to harvest while halting salinity with perennial roots."
The Manitoba branch of the Canadian Society of Soil Science summer tour came to view Rigby's salinity issues in August 2012. It was an eye-opener: the white stuff was calcium sulfate.
"Some wondered if the sulfate originated with the sulfate fertilizer that we had applied," he says.
Rigby hypothesizes that salinity may be a consequence of routine fertilizer application. The fertilizers that farmers typically use are salts that dissociate into ions. "Ammonium sulfate splits into ammonium and sulfate ions. The sulfate anion remains dissolved in the soil water. The ammonium cation displaces native calcium cations off the soil clays. As the soil water drains, the calcium and excess sulfate leach," he says. "Where the calcium sulfate solution puddles and dries, they combine as the dry white calcium sulfate salt that we see."
Ionic fertilizers are a plausible cause of salinity, but that may not be correct in every situation. Rigby notes there are other possibilities:
- Deep perennial roots and mycorrhizae, developed during 10,000 years of grassland, stabilize the soil and hold calcium ions adsorbed on the clays. Now, by killing deep roots or cutting ditches into the parent material below, calcium may be free to move.
- Ancient biology in the subsoil became starved of photosynthetic energy after sod breaking. Now, it may be releasing its biological sulphur as dead leachable sulphate.
- Deep compaction caused by high-speed turning of heavy equipment at headlands and corners suffocates roots of air, and enables salt solutions climbing up via capillarity.
- Prior to cultivation, sulphur was evenly distributed in the deep perennial Prairie soil at its maximum biological concentration limited by the sun's energy. Now, collected in low areas by soil erosion, sulphur might be in surplus relative to annual cropping photosynthesis.
- Toxins may be killing subsoil life. Cadmium from old phosphate fertilizer and from tractor tires concentrates at headlands and may kill soil fungi populations. Systemic chelating pesticides may tie up the micronutrient supply in deep root tips, far below topsoil where bacteria adapted to degrade them. In high-salt patches, pesticide biodegradation may not be occurring.
- Pure snowmelt water in sloughs may pick up calcium sulphate from the field as it climbs up the field by capillarity. Calcium sulphate solutions flowing down from hills may collide with slough water at the salinity ring around sloughs.
- Roads built of expanding clays sponge the pure water from snowmelt and add calcium to it. When compressed under passing vehicles, the salt solution may be pumped down and outwards under fields.
"I think it's an emergency," Rigby says of the growing salinity issues. "If a grower sees any spot on the farm where nothing is growing, it needs action. It's going to get bigger. Areas of landscape are being lost for future generations. They're not getting food off of them even now.
"In the dry 1930s, this area never had a massive crop failure. The rolling land always had crops in the fertile moist areas around sloughs, where today there is salinity," he adds.
Typically, the rich arable lowland no longer produces the best crop. The calcium sulphate is too high there for annual grain crops. "That's a very bad sign, especially if we get another decade of drought."
For remedies, Rigby skims off the white calcium sulphate using a grain shovel to avoid further compaction, and then returns it to the knoll. He covers the patch with straw or a loose tillage mulch to stop the evaporation that draws salts to the surface. He also uses lighter machinery, and relies on nitrogen-fixing legumes until stabilized forms of non-ionic nitrogen can be purchased. He maintains sparse old alfalfa within grain crops to sustain deep subsoil life and hold sulphur on uplands.
But first, Rigby says, we really need to understand salinity.
"Salinity is the evidence that we're making a serious agronomy mistake. Farming caused it. We caused it. It wasn't here when my family homesteaded this place. We made the decisions that produced it. We're responsible. I think we're all responsible.
"Grain could cost more to grow, but if my hypotheses are valid, there's really no other option other than to change what we're doing," he emphasizes.
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Canada Young Farmers ConferenceFri Feb 24, 2017
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Central Ontario Agriculture Conference Fri Mar 03, 2017
National Farmers Union - Ontario ConventionFri Mar 03, 2017
Re-Tooling the Diagnostic Toolbox Soils and Crops 2017Mon Mar 06, 2017