While drones have a foothold in the game of precision agriculture, some researchers are toying with the idea of using them as pollinators as well.
Researchers ordered a small drone online and souped it up with a strip of fuzz made from a horsehair paintbrush covered in a sticky gel. The device is about the size of a hummingbird, and has four spinning blades to keep it soaring. With enough practice, the scientists were able to maneuver the remote-controlled bot so that only the bristles, and not the bulky body or blades, brushed gently against a flower’s stamen to collect pollen – in this case, a wild lily (Lilium japonicum). To ensure the hairs collect pollen efficiently, the researchers covered them with ionic liquid gel (ILG), a sticky substance with a long-lasting “lift-and-stick-again” adhesive quality – perfect for taking pollen from one flower to the next. What’s more, the ILG mixture has another quality: When light hits it, it blends in with the color of its surroundings, potentially camouflaging the bot from would-be predators. | READ MORE
But natural pools of nitrogen have plenty to offer, and McDonald believes if producers don’t wait to soil test or judge the impact of weather on the crop’s early development, they might be missing an opportunity for improved N management.
Back in 2001, McDonald and OMAFRA’s then-corn specialist Greg Stewart decided to evaluate levels of organic N across Ontario’s soil zones. “Most N went down as urea or urea ammonium nitrate (UAN) applied on bare ground before the corn was planted. We wanted to raise awareness of how much organic N was available from the natural pool across Ontario,” he says.
OMAFRA’s corn N soil survey was born, in which Stewart and colleagues annually sampled between 75 and 100 different sites, evaluating available organic N in natural pools by soil type, geography and cropping history.
“We did that on an annual basis in the hopes of better understanding how the natural pool was mineralized, and to give people other options than throwing all the N up front. Pre-plant N application works from a time perspective but doesn’t give producers much opportunity to use management thinking to customize the rates based on a sound knowledge of the year’s yield potential,” McDonald says.
In 2016, the survey morphed into the “N Sentinel Project,” a three-year Grain Farmers of Ontario and Growing Forward 2 sponsored effort designed to improve current tools for estimating N fertilizer requirements. Instead of visiting dozens of sites the team focused their analyses on 23 dedicated sites across clay-loam, loam and sandy soil zones.
“In the past, we were just haphazardly going out and sampling fields across the province and it wasn’t a very organized or targeted process,” McDonald says. “It was a one shot-in-the-dark per year analysis, and we felt that although it was giving us generalities, it wasn’t able to answer the important questions that needed to be answered on an annual basis.”
What are those questions? The researchers are mostly interested in discovering the impact of weather patterns on the mineralization of the natural N pool each year, as well as the effects of previous cropping practices, temperature, moisture and soil type on background N levels.
Three sites are located in eastern Ontario, two in central Ontario, and eight between London and Guelph; the rest are scattered to the west, with the furthest located at Dresden. Eight of the sites are maintained by the University of Guelph as part of a number of the Ontario Corn Performance Trials. The other sites are maintained by farmer co-operators.
Sites are established with zero N (max 30 pounds of N per acre) in a starter band and a full-rate non-yield limiting commercial N rate. Each site is sampled four times per year between May 1 and July 1, and has its own weather station installed by Weather Innovations Network, which processes local weather data and hosts results on a dedicated website.
All sites, McDonald says, will have two replicates of the zero and full N treatments harvested for yield at maturity. “This will allow a calculation of the delta yield for each location that measures yield response to N rate,” he says. “This will also provide a [maximum economic rate of nitrogen] MERN for each site and a calibration of the [pre-sidedress nitrogen test] PSNT taken at the mid-June sample timing.”
In the previous soil N survey, he notes, there was no correlation to crop yield and thus no way of determining whether the PSNT taken to generate the survey was in the ballpark of predicting what the crop needed for economic yield.
“We know more of the background on these sites — previous management, previous rotations, etcetera, that might influence soil nitrogen levels,” says Ben Rosser, OMAFRA’s corn specialist.
“We have more info being generated on each site than in the past,” McDonald agrees.
In 2015, the corn survey generated surprising results: soil N levels were “considerably higher” than previous years’ data, due to an unusually dry spring.
“The higher-than-usual average soil nitrate levels observed in this year’s survey suggest that fertilizer N requirements in 2015 may be less than the rates generally needed in most years,” the team’s field crop report suggested, while cautioning that producers should confirm fertilizer N requirements on a field-by-field basis.
“In 2016, the results were closer to normal, or maybe just above,” Rosser says. While the season began with cooler than normal temperatures, it warmed up by June.
“With an overall average of 11.2 [parts per million] ppm in 2016, soil nitrate levels tended to be average or slightly above average relative to the five previous survey years (2011-2015), while slightly lower than 2015 values, which were well above normal,” states the team’s 2016 field crop report, before recommending normal N application practices.
But recommendations should never be taken as holy writ, the authors again caution: “Soil nitrate values are highly influenced by the environment and agronomic practices. For instance, if you are in an area which has received significantly more rainfall than other parts of the province, you may have also experienced more loss than is reflected in these results.
“The only way to know soil nitrate concentrations on your own farm is to pull soil nitrates from your own fields.”
McDonald believes producers are beginning to realize the value of managing N application more tightly, thanks to their use of Internet and social media resources promoting the practice — and the genetics they’re employing.
“The biggest change that’s occurred is that the genetic potential of new hybrids has really increased, and with that, producers are understanding how important nitrogen management is to achieving that yield potential,” he says.
A previous version of this article originally appeared in the October 2016 edition of Top Crop Manager East.
It might seem like a statement of the obvious, but right now, there’s no “obvious” strategy for maintaining nutrient levels in soil. In fact, there are multiple strategies, especially when it comes to nutrients such as phosphorous (P) and potassium (K).
It’s a surprising result, given that Ross, a farmer based in Arthur, Ont., and owner of the biogas company Ross Enterprises, spent the summer waiting for rain like every other Ontario producer. But Ross believes there’s a simple explanation: these crops were part of a commercial study he instigated last year, looking at the impact of slurry seeded cover crops on soil health, water retention and the soil microbiome, and crop yield the following year.
Put simply, the cover crops, planted along with digestate sourced from municipal waste, created prime conditions for this year’s crops.
Ross is intrigued by the system for environmental as well as business reasons – or rather, the two are intertwined. Healthy soil creates healthy crops, he says, and agricultural producers play a huge role in carbon capture. “If we improve soil organic matter by 0.4 per cent we will capture over 15 billion tonnes of greenhouse gas,” he says. “Cover cropping is one of the methods of doing this.”
Not only does cover cropping improve the environment, but it also improves the value of the land, and that value stays close to home.
“Every dollar we don’t spend importing fertilizer gives the Canadian economy a lift,” he says. “If you send money out of the country it’s just gone. If you put
money in at the bottom it will get to the top.”
It’s a philosophy that has a lot of buy-in from Ross’ community. The project saw investment of seed, time and professional resources (if not financing, which came from Ross himself) from Bio-En Power, Bartels Environmental, Cargill, FS Partners, Grand River Conservation, Pioneer Seeds, Speare Seeds and the Ontario Seed Company. Christine Brown, field crops sustainability specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), helped with the study.
How digestate-based cover cropping works
Bio-En Power, Ross’ partner, is responsible for generating most of the power for the city of Elmira, Ont. The company’s biogas plant diverts over 70,000 metric tonnes of organic waste from the landfill sites annually, and uses it to generate electricity. “What’s left is the digestate,” he says.
The digestate is a “well-blended, balanced, nutrient-rich” and pasteurized byproduct of anaerobic digestion, a process that captures the methane from waste for energy. It is also a fertilizer product that can be injected directly into the soil at key points in the season, explains Ross.
Last year’s study involved planting a multi-crop cover crop mix after wheat on three fields (700 acres) of Ross’ operation. Half the strips were treated with digestate, the rest without, and planted at different times depending on wheat harvest.
One overarching goal of the study was to look at opportunities for applying municipal waste during the growing season to extend the application window.
Brown’s interest in the study was twofold: she looked at the differences in root system biomass between the two strips, as well as ammonia losses from digestate with high pH levels. Her observations of the trial confirmed her assumptions in a few different ways.
According to Brown, every anaerobic digester has a different “recipe” of ingredients that affects the analysis of the digestate, including pH. One key observation from the study was that volatilization of nitrogen into the air as gas happens more quickly when manure or digestate has a high pH. It’s an important finding because of its direct agronomic implications where immediate incorporation is required to minimize nitrogen losses.
PH is not typically tested for in a manure analysis, but “sometimes farmers talk about their corn crop running out of [nitrogen] N and I wonder if that happens, in some cases, when the pH in the manure is higher than expected,” she explains.
“So if a farmer says they’re going to apply a high pH manure or digestate and incorporate two days later, if you’ve got a material with a high pH, then you might not have very much left at the end of two days relative to a manure with a lower pH.”
Regarding the practical benefits of using digestate along with cover crops, Brown has a theory that when digestate or any organic amendment is added to the soil, their microbial populations are feeding the soil’s existing microbial populations.
“If they’re at the surface they’re not doing much, but if you plant a cover crop you’ve got a lot more microbial activity at the root system,” she says.
There are more agronomic implications from the study. Brown also noticed that when an eight-species mix of cover crops was planted without digestate, all of the root systems demonstrated improved growth – “the diversity made a bigger difference,” she says. But when the eight-species mix was planted with digestate, the grass and radish species in the cover crop mix took over. “The bottom line is that if you’re applying digestate to a cover crop, don’t waste your money on eight different species, because a couple of those species will dominate. You may as well save your money and stay with the dominant species,” she says.
A small plot research trial initiated this spring near Arthur is evaluating digestate and municipal biosolids application at different opportunities during the growing season, including application with various cover crop mixes.
Results from Ross’ trial last year were not quantified, but the trend showed an increase in plant and root dry matter biomass of about 30 per cent where cover crops had digestate applied. Ross will continue the study “for the next several years” to evaluate its practical impact on his operation.
It’s work he believes is incredibly important, and he’s not alone in that conviction. But without credit where credit is due – and government incentives – farmers are unlikely to adopt similar measures, he says. “Farmers get blamed for a lot of stuff but we get no credit for what we do. This actually makes the world better.”
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Atlantic Farm Women's ConferenceFri Apr 28, 2017
Food and Beverage Ontario Annual ConferenceWed May 31, 2017
Ontario Agricultural Hall of Fame Induction CeremonySun Jun 11, 2017
Canolapalooza SaskatchewanTue Jun 20, 2017
Canada's Farm Progress ShowWed Jun 21, 2017
Canolapalooza ManitobaThu Jun 22, 2017