As corn hybrids are being developed to respond better to higher seed populations, interest is growing in variable-rate seeding.
For many years, blackleg disease on the Prairies was managed fairly successfully through the use of disease resistant varieties and an extended rotation.
The 2014 growing season was the worst year in recent memory for poor root nodulation and nitrogen (N) fixation in soybeans.
The wheat variety trials, posted at www.gocereals.ca, are the best source of variety performance information.
The effectiveness of fall fertilizer applications depends on a number of factors.
North American Manure Expo comes to Canada...
For the first time ever, the North American Manure Expo is being hosted within a Canadian province. The annual show is being held August 20 and 21, 2013, at the University of Guelph’s Arkell Research Station, located near Guelph, Ontario. So, what's a Manure Expo and why should you attend? This video will provide all the dirt.
Expert Dr. Susan Watkins discusses Water Sanitatio...
Expert Dr. Susan Watkins discusses Water Sanitation
The population explosion...
With the world's population increasing exponentially and farmland staying the same, BASF took to the streets to ask consumers if this trend is sustainable.
Too many variables often make it difficult to recreate the same effective strategy year after year in agriculture. But researchers and farmers are persevering in their efforts to find reliable tactics that work, and have managed to do so again with a study that indicates underseeding red clover in spring wheat can add up to an extra $100 per acre advantage for the following year’s corn crop. The findings were produced by Scott Banks, the emerging crop specialist based with the Ontario Ministry of Agriculture and Food and Ministry of Rural Affairs office in Kemptville, Ont. The project was started at the Winchester Research Farm back in 2009 – at first as a regionally significant trial – but now offers implications for farmers across the province, he says. Although spring wheat accounts for a much smaller portion of wheat production in Ontario (just 80,000 acres were harvested in 2013 compared to more than one million acres of winter wheat), the eastern part of the province traditionally grows more spring wheat than winter wheat. Of all the acres grown in Ontario last year, 37,000 acres of spring wheat was produced in eastern counties, while winter wheat production only accounted for 25,000 acres. Growers say winters, especially in far eastern Ontario, are too hard for winter wheat production to be consistently reliable. Most of the growers that are still growing spring wheat are yielding 60 to 80 bu/ac. There is a strong straw market in this area, in addition to the rotational advantages. Red clover has the added advantage of improving soil health and fixing nitrogen for the next year’s corn crop. But Banks says spring wheat growers have become reluctant about the practice. “One of the bigger complaints growers had about red clover is that it will compete with the spring wheat crop, suppressing grain yield,” Banks says. “That becomes an issue for combining and can become a bit of a challenge for straw too, particularly for guys who are selling it.” In an attempt to determine the best red clover seeding date to minimize competition with spring wheat, Banks says they began by broadcasting seed at four spring wheat growth stages, which included during planting, at herbicide application (typically Zadok stage 26-30), at flag leaf emergence or after harvest. Single-cut and double-cut red clover were assessed, both being broadcast at a rate of seven pounds per acre. The wheat crop received 90 lbs/ac of actual nitrogen in all cases and herbicide was applied on an as-needed basis per year. “As you would expect, the red clover that was seeded early in the spring, at planting or even at herbicide timing, established better,” says Banks. “There was more volume of red clover going into the fall, which contributed more nitrogen and organic matter to the field, and so there was more advantage to earlier planting.” At harvest, Banks says they were surprised to see that the red clover treatment had not suppressed spring wheat yields but had actually slightly increased yield. “When we looked at it over the four years, for most years there was a two- to three-bushel increase in spring wheat by having red clover there,” says Banks. “Statistically, that may not be valid, but we didn’t see a reduction in the spring wheat yield.” More importantly, he says, was the impact on the corn crop the following year. “As we’ve seen in winter wheat, the red clover’s impact on the corn showed up as a fair contribution to yield.”With nothing more than 100 lbs/ac of actual nitrogen applied to the following year’s corn crop, Banks says they saw anywhere from a five to 22 bu/ac yield boost from the red clover. The red clover treatment that performed the best was the single-cut clover that was seeded at planting for a gain of $99.57/ac, based on a corn value of $4.50/bu. “Overall, single cut maybe looks like it contributed a little bit more to the yield but it was hard to say; statistically, there’s a difference,” Banks notes. “Single cut sometimes looks more lush, but it’s hard to say it was any more than a visual thing and I don’t think there’s a big enough difference to go one way or another.”
On a farm field, phosphorus is an essential crop nutrient. But in water bodies, too much phosphorus can cause serious problems, including increased algae growth. Algae blooms can result in oxygen depletion, leading to fish kills, and blue-green algae can release toxins into the water. So a project is underway to develop a field-scale tool to help farmers keep phosphorus on the land. “There has been a lot of talk in the news recently about more algae blooms in Lake Erie. After it had been cleaned up in the 1990s, it’s getting worse again. Lake Winnipeg is having a lot of algae bloom problems. Lake Champlain’s Missisquoi Bay has blue-green algae problems. The culprit is excess phosphorus. And agriculture is in the crosshairs to some extent as being blamed for part of that excess phosphorus,” says Keith Reid, a soil scientist with Agriculture and Agri-Food Canada (AAFC) who is leading the project. He adds, “Excess phosphorus in the water doesn’t translate into a terribly large loss from land, but we want to try to reduce that loss to do agriculture’s part in keeping our lakes swimmable and fishable.” Called Project P, this research is funded by AAFC. The tool is being designed for conditions in eastern Canada, and Reid is working with several other AAFC research scientists in eastern Canada, as well as provincial government and university researchers in Ontario and Quebec. The tool aims to predict fields, or parts of fields, at high risk of phosphorus (P) loss. Reid explains, “If you’re going to ask a farmer to do something, let’s do it where it’s going to be effective, where it’s actually going to make a difference. This tool should identify where the high-risk areas are so farmers can focus their attention on those areas.” A next-generation phosphorus index“Essentially, we’re looking to improve the phosphorus index,” notes Reid. “The P index was developed as a tool to try to identify hot spots – areas with the greatest risk of phosphorus losses from agricultural land. An example would be a livestock operation that has a small land base with fields near a stream, and they’ve been putting their manure on those fields continually and building up the soil test phosphorus. So those fields have a lot of phosphorus that’s available for loss and easy transport into the water.” The idea of a phosphorus index was first proposed about two decades ago. Since then, various American states and several provinces, including Ontario, have adopted a P index and adapted it to their own conditions and needs. “[Ontario’s] current P index, on a large scale, accounts for most of the risk factors. But no one has taken the time to determine if the index’s predictions compare well with what is actually showing up in the water. The current index also misses some of the factors that are a big part of agriculture in Ontario, including tile drains,” says Reid. He stresses that Project P is not about creating a new index to replace P indexes that Ontario, Quebec or the Atlantic provinces already have. “Our aim is to provide the scientific background that the provinces can use when they adapt their P indexes.” Reid and his research team will be filling some of the information gaps in the current index to develop an improved model. Then they’ll test the prototype model in the field to make sure it works as expected. Developing and testing the prototypeThe researchers are already working on the prototype. “We have been gathering all the information we can out of the scientific literature, from studies in Ontario and in regions with similar climates, soils and cropping systems. We’re examining what those studies are finding, and we’re putting that together in a model,” Reid says. Predicting phosphorus loss from agricultural land is challenging because it is influenced by many factors, such as nutrient application rate, placement and timing, soil test P, erodibility of the soil surface, rainfall and snowmelt amounts and surface runoff and subsurface flow patterns, including connectivity with nearby water bodies. Some practices to reduce the risk of phosphorus loss are already clear. Reid notes, “For instance, we know we can reduce the risk by just getting a phosphorus application worked into the soil or subsurface placed, rather than leaving it on the surface. And we know we can reduce the risk by waiting until the ground is dried up in the spring before applying phosphorus.” But the effect of tile drainage on phosphorus loss is not so clear. “I’ve done comparisons of phosphorus indexes across U.S. states in particular, which have most of the information [on tile drainage considerations], and they treat tile drains as either all good or all bad,” says Reid. “The one mindset is: tile drains divert what would be surface runoff into the tiles so you reduce soil erosion. Therefore, tile drains reduce the risk of phosphorus loss. The other mindset is: tile drains have more connectivity between the field and the water, so it is easier for phosphorus applied in the field to move off the field and into the water. Therefore, tile drainage increases the risk of phosphorus loss. But, in reality, both of those are happening simultaneously.” As well, he says phosphorus loss in tile drains varies with soil type and with the size of the area drained by the tiles. The researchers hope to have their prototype ready for field testing by the spring of 2015 and to finalize the tool in 2016. “[In our tool,] we’re trying to simplify many factors so the tool can be used on the farm. We don’t want a tool that requires a whole lot of very complex measurements and inputs before you can run it,” explains Reid. But those simplifications mean the model is being designed to predict general trends, not how many grams of phosphorus will be lost from a field. “So, in our field testing, if the model identifies an area as a high risk for phosphorus loss, then we would expect to see higher levels of phosphorus in the downstream water. And if it identifies a low-risk area, we would expect to see lower concentrations of phosphorus.” The researchers are in the process of looking for field sites where they can compare the model’s predictions with what is actually happening. The sites have to meet several criteria. “We need sites with water quality measurements at a fine-enough time-scale that they give a good picture of what is showing up in the water. And the measurements have to be for a small-enough area that we can make some conclusions about what the water quality data mean relative to the land area draining into that stream. For instance, if the water quality is being measured at the mouth of the large river like the Grand River, it won’t be very useful for our purposes; there’s just way too much going on in that watershed. So the field sites need to be up in smaller sub-watersheds,” explains Reid. “And then we have to combine [those criteria] with being able to get the information about the agricultural practices on the land. That will enable us to run the model and compare the results with the water quality data.” Turning the tool’s results into practical actionAccording to Reid, the main users of the tool will likely be nutrient management planners. “We would expect to see the tool incorporated into, for example, [Ontario’s] NMAN software, once we’re happy with the way the model is working.” He adds, “I would also hope the model is transparent enough that a farmer could use it, recognizing that some farmers will have an interest and some won’t because they’ve got a lot of other things on their minds.” Reid expects the results generated by the tool will be provided to users in a way that indicates why a certain area is identified as having a high risk of phosphorus loss; for example, whether the risk is mainly due to soil erosion or to phosphorus application factors. That type of information would point the user towards which types of best-management practices would be most effective in reducing phosphorus loss. He notes, “This project is working in the context of: how can we farm a little bit better to both keep the phosphorus on the land and keep the water clean, and also have a profitable cropping system?”
Ontario crop researchers are putting the Greenseeker technology under the microscope to see if it can work for the wheat crop. They’re testing its ability to analyze the nitrogen (N) needs of the crop, which would help farmers apply the right amount of fertilizer. Peter Johnson, provincial cereal specialist with the Ontario Ministry of Agriculture and Food and Ministry of Rural Affairs, along with Dr. David Hooker of the University of Guelph, Ridgetown Campus, is leading trials to adapt the system to Ontario’s conditions. Johnson’s goal is to increase profits for farmers by applying higher N rates to areas where the crop will respond while reducing the rates where there’s a lower response. “At the end of the day, we’re trying to figure out how to have better-targeted nitrogen applications, more yield where possible, less environmental impact where the yield doesn’t have that potential, and more dollars in the grower’s pocket,” says Johnson. The Greenseeker system from Trimble Agriculture uses optical sensors with an integrated application system to measure crop status and variably apply the crop’s nitrogen requirements. The technology works in real time, allowing the operators to make variable rate app-lications on the go. The sensor uses light-emitting diodes to generate red and near-infrared (NIR) light. The light is reflected off of the crop and measured by a photodiode at the front of the sensor head. Red light is absorbed by plant chlorophyll and healthy plants absorb more red light and reflect larger amounts of NIR than those that are unhealthy. The reflectance values are used to calculate the Normalized Difference Vegetation Index (NDVI), which is an indirect measurement of the crop’s above-ground growth. By comparing the NDVI of the crop being evaluated to that of an N-rich strip in the field, the technology can be used to respond to field variability. As the applicator moves across the field, a built-in microprocessor analyzes the NDVI readings and determines the N requirements that are needed to meet full yield potential. Pre-determined algorithms calculate the amount of N required. The information is relayed to the rate controller to provide variable rate N application in real time as the applicator moves across the field. Ontario researchers are working with an algorithm that was created at the University of Kentucky for soft red winter wheat. Johnson says the trials have been designed to evaluate the algorithm and adapt it to Ontario field conditions. According to previous research in Ontario’s fixed rate trials, the wheat crop shows a response to 150 pounds of nitrogen 60 per cent of the time. With the Greenseeker’s ability to vary the application rate, Johnson is hoping to apply less nitrogen but still match the yield response of a 150-pound application.In the first year of the trials in 2013, the system didn’t produce a positive economic response. Johnson suspects that they didn’t set the target rate high enough. “In many fields, a fixed rate with a higher rate than what a Greenseeker applied was our most economical rate,” he says. The target was set at a higher rate in 2014, but Johnson was not comfortable with the much higher amount of nitrogen that was applied, which reached 200 pounds in some areas. While it didn’t achieve the desired results, Johnson is still intrigued by the system. “I would look at the field, walk it and see a nice uniform field, and then you get the NDVI map and there were all kinds of differences,” says Johnson. “How real are those differences? We don’t know that.”Dr. Lloyd Murdock, a soil specialist at the University of Kentucky, had a similar experience when writing the algorithm. Murdock received a grant to run experiments with the Greenseeker, which was developed at Oklahoma State University. Murdock says farmers were generally doing a good job of estimating the amount of N needed for the crop by counting the tillers and looking at the colour. The method, however, is highly subjective and doesn’t address the variability in the field. “You have an instrument that could actually look at the crop and see what it is doing and make that assumption, not on a subjective factor, but on the factor on how it has grown and what it’s done,” says Murdock.He evaluated the technology using algorithms developed in Virginia and Oklahoma. Calling the initial results “OK,” he notes that they couldn’t beat the results of the old system. The researchers applied less N using the two algorithms, but the yields were lower. “When we did the economics, we were getting less money. So it became apparent to us that the algorithm has to be a regional thing,” says Murdock. In a process to regionalize the system for Kentucky (which took approximately four years), the researchers conducted several small plot trials with different rates of N applied at different times around the jointing stages of the crop. They used hand-held Greenseeker units to record the readings that were then used to develop the algorithm and realize the technology’s potential of applying N more effectively. The algorithm was then tested on farmers’ fields and was found to be better than the old method by raising the yields and economic returns. “Two years ago, when we had a lot of N carryover from a poor corn crop and lodging of the wheat plant . . . that year was terrible,” recalls Murdock. “But if you used the Greenseeker, it picked up that difference and didn’t put much N on. It’s based on the fact the technology is better than our eyes.” With a yield gain of about five to seven bushels per acre, Murdock notes that the $20,000 Greenseeker system isn’t for everyone. Farmers who have 1,000 or more acres and who plant wheat every year would be more likely to see a quick return on the investment. Johnson’s team is also seeking ways to regionalize the algorithm for Ontario. They’re using hand-held units to record NDVI readings from sites that have received various amounts of N, a method similar to the Kentucky algorithm. The results would then be correlated with the yields. “If we get enough of these sites, maybe we can actually find out what that curve should look like under Ontario conditions,” adds Johnson. Another important factor is to ensure that nutrients such as sulphur and manganese aren’t deficient. The Ontario researchers learned that the Greenseeker will read them as a nitrogen deficiency and apply N where it won’t help at all. “We need to make sure that we solve those issues before the Greenseeker technology is going to do what we want it to do,” says Johnson. In addition to the Greenseeker technology, they’re also flying unmanned aviation vehicles with multi-spectral cameras to see if that might be a more effective way of gauging the variability in the fields. “Putting a prescription map into an applicator might be just as effective, or even more effective than trying to read it on the go because there is always the challenge of the lag time between the sensor readings and when we change the rate,” says Johnson. “It’s quick, but is it quick enough? There are lots of questions we’re still trying to address.”
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