Editor’s note: The following was written by Mark Licht, Iowa State University assistant professor and Extension cropping systems specialist, for the university’s Integrated Crop Management News blog Oct. 29.
It doesn’t happen every year, but it does occur — snow accumulation before harvest is complete. Here are some considerations and tips for dealing with this unique situation.
The probability of a first snow sticking around is fairly low, but patience is needed to allow the grain and soil conditions to dry before resuming harvest. Whenever possible, wait for the soil conditions to be favorable to avoid compaction and rutting and avoid or minimize tillage in fields with high soil moisture. This may mean waiting for the ground to freeze.
Harvesting corn or soybean after snow can be problematic. Wetting and freezing causes split pods and seed shattering in soybean, while crops with wet pods and husks can also be problematic because evaporative cooling may cause plant material to stick to the grain.
This results in problems with cleaning the grain properly and is most troublesome when air temperatures are 27–35 degrees.
Harvesting grain that is frozen and wet is hard on combines and can potentially damage equipment. Take time to get combine settings correct, take preventative maintenance seriously and make appropriate repairs.
Consider the tradeoff between harvesting wet grain (maybe as high as 25% grain moisture) with in-field yield losses due to delayed harvest. How much in-field yield is tolerable if the alternative is $1 per bushel drying cost?
Standing corn can withstand overwintering given the right conditions. Grain loss due to delayed harvest is minimal in November (0-5 bu./acre) but has the potential to increase substantially if harvest is delayed into the winter and spring months (up to 60 bu./acre losses; see table). Stalk lodging, ear drop and wildlife feeding are the main causes of yield loss.
Lastly, consider how a delay in harvest until spring affects next year’s crop. Consider factors like potential labor shortages, fertilizer application shifts, additional risk for volunteer corn and delayed planting.