Frequent rains and wet soils across the province have slowed or prevented field work. Soil compaction is likely to be an issue this year, especially for farmers trying to get manure spread ahead of spring planting. Fertilizer has been moving out to farms with storage. Retailers are full and ready to apply product once soil conditions are favourable.
With wet soil conditions, there is concern about loss of nitrogen (N) through denitrification where fertilizer has been applied, especially in winter wheat fields. Denitrification is the bacterial conversion of the nitrate (NO3) form of N in the soil to both nitrogen gas (N2) and nitrous oxide (N2O), both of which can be lost to the atmosphere. This occurs when soils are saturated with water, especially in heavy clay soils with poor drainage and frequent rainfall.
Denitrification rate is a function of time, soil temperature, and the amount of nitrate-N in the soil. When N is still in the urea or ammonium (NH3) forms, it cannot be lost via leaching or denitrification. Urea applied to the surface may take 7-14 days to convert to nitrate, and so applications immediately before the onset of rains may have less available for loss than those applied earlier.
The warmer the soil temperatures, the quicker the conversion of nitrate to losable forms, and with warming temperatures now, losses can add up, assuming the soil remains saturated. Table 1 shows the effect of soil temperature on nitrate loss. Keep in mind that that the nitrate form of N is at risk of denitrification in wet weather.
| Soil Temperature (°C) | Potential denitrification rate (percentage of NO3-N in soil) |
| < 12 | 1% – 2% per day |
| 12 to 18 | 2% – 3% per day |
| > 18 | 4% – 5% per day |
For those fields with no N or a small amount applied, losses will be low, but the balance of N should be applied to wheat as soon as possible.
Growing Degree Day (Base 0˚C) accumulation is ahead of normal across the province (Table 2), which has advanced winter cereal development. For cereal crops, this may make timing fertilizer and fungicide applications more difficult. If the flag leaf is emerged herbicide applications should be avoided. Chickweed, dandelion and shepherd’s purse are flowering so any herbicide applications targeting those weeds will have little value. Forage cereals are quickly approaching flag leaf in the most advanced fields, and harvest is more likely to conflict with planting spring crops. Where forage harvest conflicts with grain planting, it makes more financial sense to park the planter, harvest the forage, then resume planting. It’s difficult to purchase digestible fibre to replace lost quality from a late forage harvest, but corn yields are stable with seeding dates prior to May 15th. Michigan State University’s Dr. Kim Cassida explains this value/quality trade-off with alfalfa and corn starting at 8:05 in this video, although the forage quality information applies to winter cereals too.
Many winter annual and perennial weeds are further along than normal. Canada fleabane, purple deadnettle, chickweed, and dandelion have been mentioned as species more prominent this spring. Wet weather has delayed timely herbicide applications. As weeds get bigger, they are more tolerant to herbicides. The highest labelled rate should be used when weeds are at an advanced stage. Applying during the middle of the day, when ambient air temperatures are usually higher, has been shown to improve the effectiveness of herbicides.
Disease pressure in wheat and other cereals is low, but powdery mildew and Septoria leaf disease can be found in the lower canopy, especially in very susceptible varieties. Continue to monitor progression and determine if a fungicide application (pre-FHB fungicide timing (T3)) may be needed. Stripe rust has been found in mid-Illinois (Champaign area) and with recent storm fronts, check for infection over the next 2 weeks. When temperatures are cool and humid, disease incidence and severity can increase rapidly, reducing yields. This is a disease you want to be on top of! To track stripe rust progress in Ontario and the US, go to the Ag Pest Monitor.
The Soil Health Assessment & Plan (SHAP) tool is now available for growers to measure their soil health. This new tool is still being fine-tuned, and the Soils at Guelph SHAP Ground-truthing Project is looking for farmer cooperators to contribute soil samples and answer a few questions about the soil Best Management Practices they use on their farm. Please email soils@uoguelph.ca to participate in this project along with your name, county, and the number of fields you would like to sample.
Ridgetown
- Winter wheat development is still about 2 weeks ahead of normal. 80-90% of the crop has received a nitrogen application. Some leaf burn was reported where a frosty morning followed N application, but no yield impact is anticipated. Powdery mildew is a problem in thick stands.
- Winter barley is not as advanced as winter wheat.
- Cereal rye and winter triticale are at GS 37, and forage harvest is anticipated in about 2 weeks.
- A few corn acres have been planted around Dresden, Thamesville, Rodney and Chatham.
Mount Forest
- Winter wheat overwintered well, except for some clay fields seeded in October in Bruce County. The wheat is mostly at GS 30-32 (about a week ahead of normal). Most nitrogen has gone on as a single application. Disease pressure is currently low, so T1 fungicide use may be less this year.
- Fertilizer has gone out onto some hay fields. Some fall-seeded stands in Bruce County did not overwinter well.
- Spring cereal acres have increased in the region, with many intended as forage.
- A few corn fields have been planted on gravelly ground around Holstein.
- IP soybean and edible bean acres under contract have also increased in the region. Clear communication around weed control in these crops will be critical for success.
- Winter canola is starting to flower around Walkerton.
- Most field peas have been planted.
Cobourg
- Strip tillage is increasing in the region. Leaving undisturbed soil between crop rows is particularly helpful in reducing erosion on the hilly terrain found in this part of the province.
- Wheat overwintered very well. Most fields have had an application of nitrogen. Many growers opted to apply the N all upfront due to limited application windows in the forecast. The crop is advancing quickly.
- Hay fields have overwintered well.
- Spring cereal seeding is mostly finished. Barley is looking good.
- A few hundred acres of corn have been planted on sandy soils in the region. For most growers it was too early and now too wet to start planting corn.
- Canola acres – both winter and spring – are increasing in the region to diversify the crop rotation.
Northern Ontario
- Winter cereal development is ahead of normal. Scouting is advised so growers do not miss the application window for nitrogen. Aim to get N applied before GS 30-32.
- Hay fields are also maturing faster than normal. Watch maturity (not the calendar!) to time first cut for high quality forage.
- Timiskaming: Normal in terms of spring conditions. Field work will likely start in a couple of weeks. Conditions are looking pretty good if they do not get too much rain. Winter wheat is ahead of normal. A fair amount of frost seeding happened in Timiskaming this year.
- Cochrane: Not too far ahead, given the recent snow and frost. Seeding should start soon.
- Nipissing: Winter wheat development is ahead of normal. Two Yield Enhancement Network (YEN) winter wheat fields are in the Cash Bay area. A limited amount of frost seeded cereals went in. Some spring cereals were planted last week.
- Thunder Bay: Fertilizer went out and some are getting ready for seeding but will not get on the field for at least a week because of the wet conditions.
- Rainy River: Winter was warmer and drier than usual, but recent rain/snow events have helped. Not good planting conditions yet. Some frost seeding of spring cereals was done on a few fields. Emo is hosting the Northwest International Ag Expo on July 26 -27th. There will be workshops, livestock and crop speakers, as well as live soil interaction demonstrations. Additional information and updates will be posted here.
Agricorp Deadlines
Contact Agricorp ahead of the deadlines about their programs.
May 10th
- Apply for/change Grains & Oilseeds Production Insurance
- Apply for/change Risk Management Program: Grains & Oilseeds
- Apply for/change and pay premiums for Forage Rainfall Insurance
- Apply for/change New Forage Seeding Production Insurance (spring-seeded crops)
Weather Data – April 22 – 28, 2024
| Location | Highest Temp (°C) | Lowest Temp (°C) | Rain for Week (mm) | Rain (mm) April 1st | GDD0C April 1st | GDD5C April 1st |
| HARROW | ||||||
| 2024 | 25.6 | -3.4 | 28.2 | 98.2 | 284 | 147 |
| 2023 | 20.6 | 0.4 | 5.9 | 25.7 | 219 | 117 |
| 2022 | 26.0 | -2.7 | 26.4 | 54.4 | 166 | 72 |
| 10YR Norm (11-20) | 14.8 | 2.1 | 26.2 | 72.2 | 176 | 58 |
| RIDGETOWN | ||||||
| 2024 | 23.8 | -3.4 | 25.6 | 106.8 | 254 | 121 |
| 2023 | 19.8 | -1.1 | 12.8 | 72.3 | 206 | 112 |
| 2022 | 26.6 | -3.0 | 17.9 | 46.3 | 146 | 58 |
| 10YR Norm (11-20) | 13.7 | 1.0 | 18.9 | 61.6 | 152 | 37 |
| SARNIA | ||||||
| 2024 | 26.8 | -2.3 | 6.6 | 71.2 | 250 | 119 |
| 2023 | 18.6 | 0.7 | 12.2 | 68.2 | 212 | 116 |
| 2022 | 27.9 | -4.1 | 13.3 | 30.1 | 152 | 68 |
| 10YR Norm (11-20) | 14.5 | 1.0 | 19.8 | 66.6 | 143 | 31 |
| LONDON | ||||||
| 2024 | 22.5 | -1.6 | 8.2 | 83.9 | 245 | 110 |
| 2023 | 20.1 | 0.0 | 38.2 | 95.4 | 203 | 110 |
| 2022 | 25.3 | -3.1 | 23.9 | 54.7 | 139 | 58 |
| 10YR Norm (11-20) | 13.9 | 1.1 | 21.5 | 74.1 | 142 | 31 |
| BRANTFORD | ||||||
| 2024 | 20.8 | -2.5 | 7.7 | 74.3 | 224 | 94 |
| 2023 | 22.5 | 0.2 | 26.7 | 73.1 | 195 | 101 |
| 2022 | 26.2 | -2.9 | 16.4 | 32.7 | 144 | 57 |
| WELLAND | ||||||
| 2024 | 17.8 | -2.7 | 6.4 | 105.2 | 246 | 112 |
| 2023 | 23.7 | 1.3 | 14.8 | 55.9 | 199 | 102 |
| 2022 | 26.5 | -3.9 | 18.2 | 36.9 | 162 | 68 |
| 10YR Norm (11-20) | 14.5 | 0.9 | 23.8 | 78.8 | 145 | 33 |
| GODERICH | ||||||
| 2024 | 23.6 | -2.2 | 9.4 | 79.7 | 218 | 91 |
| 2023 | 16.7 | -0.3 | 13.0 | 40.2 | 185 | 98 |
| 2022 | 25.2 | -2.3 | 28.4 | 50.6 | 132 | 53 |
| 10YR Norm (11-20) | 12.8 | 0.6 | 17.1 | 61.2 | 117 | 15 |
| ELORA | ||||||
| 2024 | 20.4 | -3.6 | 9.3 | 77.3 | 193 | 70 |
| 2023 | 20.6 | -2.0 | 33.6 | 53.3 | 177 | 92 |
| 2022 | 25.2 | -2.9 | 19.3 | 35.3 | 123 | 45 |
| 10YR Norm (11-20) | 12.5 | -0.6 | 22.0 | 77.1 | 107 | 9 |
| MOUNT FOREST | ||||||
| 2024 | 19.3 | -2.9 | 19.6 | 110.0 | 189 | 69 |
| 2023 | 17.3 | -3.0 | 28.8 | 72.5 | 177 | 94 |
| 2022 | 24.6 | -2.6 | 34.5 | 62.3 | 117 | 43 |
| 10YR Norm (11-20) | 12.0 | -0.4 | 19.0 | 68.5 | 95 | 4 |
| BARRIE | ||||||
| 2024 | 19.6 | -4.0 | 16.6 | 168.4 | 174 | 54 |
| 2023 | 18.5 | -1.6 | 34.3 | 73.7 | 167 | 84 |
| 2022 | 19.8 | -4.4 | 27.2 | 55.6 | 113 | 33 |
| 10YR Norm (11-20) | 12.3 | -1.1 | 20.3 | 68.0 | 91 | 3 |
| PETERBOROUGH | ||||||
| 2024 | 23.7 | -6.3 | 12.5 | 116.7 | 190 | 66 |
| 2023 | 23.4 | -0.1 | 22.3 | 54.9 | 182 | 93 |
| 2022 | 21.8 | -5.7 | 27.3 | 47.4 | 126 | 39 |
| 10YR Norm (11-20) | 13.3 | -0.8 | 19.9 | 67.2 | 111 | 11 |
| KEMPTVILLE | ||||||
| 2024 | 24.2 | -4.0 | 27.0 | 117.5 | 193 | 70 |
| 2023 | 26.0 | -1.0 | 11.7 | 76.6 | 181 | 98 |
| 2022 | 15.5 | -4.4 | 18.2 | 72.4 | 139 | 37 |
| 10YR Norm (11-20) | 13.2 | -0.3 | 20.4 | 74.7 | 116 | 18 |
| SUDBURY | ||||||
| 2024 | 14.0 | -9.9 | 26.9 | 156.9 | 127 | 27 |
| 2023 | 10.0 | -5.7 | 21.6 | 57.1 | 94 | 42 |
| 2022 | 19.6 | -3.7 | 42.3 | 75.3 | 65 | 9 |
| 10YR Norm (11-20) | 10.2 | -3.0 | 13.9 | 64.5 | 40 | 0 |
| EARLTON | ||||||
| 2024 | 15.3 | -11.6 | 15.3 | 126.1 | 114 | 21 |
| 2023 | 10.5 | -4.9 | 42.5 | 56.5 | 83 | 31 |
| 2022 | 16.7 | -5.7 | 14.9 | 44.6 | 55 | 7 |
| 10YR Norm (11-20) | 8.8 | -4.0 | 13.5 | 49.8 | 21 | 0 |
| SAULT STE MARIE | ||||||
| 2024 | 20.1 | -6.4 | 18.7 | 104.3 | 147 | 35 |
| 2023 | 11.2 | -2.7 | 21.4 | 45.2 | 102 | 45 |
| 2022 | 12.7 | -3.8 | 28.9 | 109.4 | 57 | 4 |
| 10YR Norm (11-20) | 10.2 | -3.7 | 15.6 | 64.3 | 38 | 0 |
| THUNDER BAY | ||||||
| 2024 | 19.3 | -7.1 | 15.4 | 47.6 | 108 | 16 |
| 2023 | 6.2 | -7.9 | 14.9 | 49.6 | 55 | 18 |
| 2022 | 9.8 | -7.2 | 98.4 | 168.9 | 32 | 1 |
| 10YR Norm (11-20) | 11.3 | -4.8 | 12.9 | 41.2 | 35 | 0 |
| FORT FRANCES | ||||||
| 2024 | 19.9 | -6.4 | 15.1 | 27.7 | 125 | 22 |
| 2023 | 8.7 | -10.6 | 14.5 | 35.4 | 60 | 23 |
| 2022 | 7.0 | -13.7 | 85.1 | 141.8 | 25 | 0 |
| 10YR Norm (11-20) | 11.8 | -3.6 | 12.0 | 34.9 | 46 | 0 |