Which is greater: yield gained from early planting or yield lost from uneven emergence?April 1, 2014 | Category: Agronomy |
Rapid, uniform emergence (all your crop up in 12 hours) is one of the key factors in setting your corn crop up for maximum yield. There are only a few requirements you need in the seed zone to set the crop up right – sufficient and uniform soil moisture, soil temperature, seed to soil contact and a crust-free surface soil. As April rounds the corner and spring feels like it has arrived, soil temperature is one of the key factors, especially in early planting, to ensure you get rapid uniform emergence. Yield lost from uneven emergence will hit you much harder than yield gained from early planting. Remember, the planting window is bigger than you think.
Soil temperature is an easy factor to measure in the field. When soil temperatures are below 10°C, it can cause variable and slow emergence. As soils reach 12⁰C and higher, emergence will likely occur in seven days or less. Uneven soil temperature in the seed zone, caused by variable soil texture, colour, drainage, residue and seeding depth are most critical when temperatures are below 10°C. To help manage soil temperature in no-till fields, consider using row-cleaners or strip tillage to help warm the seed zone.
To test your soil temperature, take a measurement in the late morning, 10 cm (4 inches) down. If your reading is 10°C or above and the forecast looks good, then soil temperatures are favourable. As we move into May, soil moisture will play a larger role in determining seeding time. During the imbibition period when the seed uptakes water, suitable soil temperature is crucial to reducing stress on the seed. Keep in mind that a cold rain in the first couple of days after planting can cause significant stress to the plant.
You can monitor your soil temperature easily with a digital meat thermometer. Remember, yield lost from uneven emergence will be much greater than yield gained from early planting. Make sure your seed bed is ideal before heading to the field.
Laura Johnston, CCA-ON, Maizex Seeds Yield Specialist, West Elgin County