Wednesday, June 15th was the fourth and final northern agribusiness breakfast meeting for the 2022 planting season. Thank you to everyone who was able to attend these meetings and share what is happening on the ground across the north.
Ben Rosser, OMAFRA Corn Specialist, shared some research results on optimizing nitrogen application rates, and the impacts of delayed harvest.
Optimizing Nitrogen Rates on Corn
A ten-year trial at the Ontario Crops Research Centre – Elora showed that rainfall was a major factor in determining corn yield. The researchers identified a critical window for rain between mid-June and mid-July. As precipitation during this timeframe increased, the optimum N rate also increased to feed the higher yield potential. Results showed that for every millimetre of precipitation in that critical window, the crop needed an additional 1.5 lbs of N/acre above the base rate of 100-110 lbs N/acre to optimize the rate. Since in-crop N applications typically occur before mid-July, growers trying to optimize their N rate should look at both how much rainfall they’ve received and the forecast to help decide how much N to apply.
This work was done on continuous corn plots to remove any rotation impact on N mineralization. Different N rates were applied to plots at varying amounts from 27 lbs N/acre to 291 lbs N/acre both preplant or side-dressed, to identify trends of insufficient N or overabundant N rates. These were then used to calculate the Most Economic Rate of Nitrogen (MERN) for a given year. High rainfall years showed that higher N rates were more profitable, and years with drier periods from mid-June to mid-July correlated with lower MERN rates, and lower rates of N being more profitable.
What does this mean for the north? Soils with high organic matter levels (>4%) and corn following a perennial forage in rotation may have greater natural N mineralization that could increase the variability in optimal N rates year-to-year. Heavier-textured soils are more prone to N losses, which need to be factored in when determining optimal N rates. Additionally, the critical mid-June to mid-July window where precipitation determined yield potential may be more closely tied to crop maturity rather than calendar dates. This key timing may be slightly later in the north.
Yield Effects of Delayed Grain Corn Harvest
Research by Dr. Dave Hooker at the University of Guelph – Ridgetown Campus explored the yield impact of leaving grain corn standing in the field over winter. Ridgetown does not typically get much snow, so there was little yield difference between harvesting the crop in late fall compared to spring, allowing growers to save on drying and storage costs. However, a trial site north of London (in Lake Huron’s snow belt) had yield losses up to 100% as the amount of snow increased. Some of the loss was due to the crop lodging under the weight of the snow, but far more was attributed to the root system breaking down with spring thaws and being unable to support the crop until combining.
Experience in Manitoba suggests that harvesting corn in the spring, prepping the ground for the next crop, and getting the new crop established can be very challenging in a short planting window. Wet spring soil conditions delay field operations. Finding a spring window with ground frozen hard enough to carry a combine is unreliable.
What does this mean for the north? Leaving a grain corn crop over winter in a snow belt region is not a good idea. Growers outside of the precipitation shadow of the Great Lakes may want to do some test strips and see how well available hybrids stand up under northern snow loads. With fewer freeze-thaw cycles in the north compared to the trial locations, it is unknown how well a corn crop’s root system will overwinter.
Regional Corn Rootworm Trap Network
Tracey Baute, OMAFRA Field Crops Entomologist, is looking for participants in a province-wide corn rootworm trap network. Trap supplies are free to growers and crop consultants, thanks to funding from the Grain Farmers of Ontario (GFO) and the Agricultural Biotechnology Stewardship Technical Committee (ABSTC).
While corn rootworm is not yet a serious problem in northern Ontario, very little is known about the species and populations present here. Last year Manitoba set up traps for this network and found western corn rootworm in their fields. Québec is known to have challenges with both northern and western corn rootworm. Trap data from northern Ontario will provide a clearer picture of corn rootworm distribution in Canada and help the crops sector stay ahead of this pest.
More information on signing up and how to trap corn rootworm is available here.
Overall, crops are in great shape. The district is getting some timely rain now.
Lodging is a common problem in spring cereals. Plant growth regulators have been going out in the last few days to help manage lodging. Some aphids have been found on oats.
Soybeans are looking good. While some fields were rolled before emergence, many bean growers are waiting to roll fields after soybeans come up to prevent crusting issues.
Canola pest levels are lower than average so far. Not many flea beetles have been found. Early seeded canola is not showing much swede midge damage either. Canola is not yet bolting but may start in the next 10-14 days.
New alfalfa seedings went into excellent conditions and the stands reflect this.
In general, the cereal crop looks very good. Fungicide has been applied on winter wheat between showers. Barley yellow dwarf virus is an issue in winter wheat.
Canola and soybeans are somewhat variable, but no major concerns right now.
Frequent rains are making hay harvest challenging.
A wet spring has prolonged seeding, so there is a lot of variability in crop maturity across the district.
Corn maturity ranges from 3-4 leaf stage to just planted and not yet emerged.
Early seeded canola may start bolting in the next 10-14 days, while the last fields to go in are only a couple of inches tall. The crop looks good so far, and no major pest issues were reported.
There were a lot of issues establishing new forage stands in 2021. Many of these will be taken for first cut, then terminated. Some new seedings are still going in as soil conditions allow.
Thunder Bay District
Seeding is pretty much done, thanks to a spell of dry weather last week. This is later than normal, but with good conditions through the growing season and into the fall, crops may still yield well. Many fields without tile drainage have been seeded to barley. These may have a perennial forage crop under-seeded as well.
Programs are available to help producers in northwestern Ontario dealing with excess rain. The deadline to enroll in AgriStability is June 30. Producers are reminded to phone in any Unseeded Acreage claims.
Wildlife damage (example: sandhill cranes eating corn seedlings) is an insured peril under the Grains & Oilseeds production insurance, provided it is the major source of yield loss. However, if wildlife damage occurs repeatedly year-over-year, this may drag down the average farm yield.
July 21st – the Timiskaming Crops Coalition is hosting a tour of the Ontario Crops Research Centre – New Liskeard (formerly NLARS) in the afternoon, with a crop tour in the evening. More details to come.