Blog: The Wheat Sheaf
Handling and Storage of a Possibly Wet Harvest
Most producers have some crop left out in the field, and most were hit with snow and at least -4 C during the first week of October. The people north of Edmonton seemed to have escaped without the snow, this time, but we are all in a period of wait and see, with the anticipation of a tough harvest coming for any crop left out. So, what to do?
For those with grain dryers the answer is simple, go when you can and dry the crop down, being careful that the right airflow rate and static pressures have been analyzed before any crop drying is undertaken. Due to the time of year we have entered into, crop drying of any grains that remain on the field will be the norm, unless the long-range forecasts are wrong and we have a period of warm drying windy days still to come. However, for now, we will assume the same cycle of wet weather followed by a period of drying for a few days only, and the cool temperatures will continue. For those who have grain aeration or natural air-drying systems, we should use it if we have it. When it comes to storage of grain, to borrow a PAMI slogan, “It’s all about the airflow rate”. There is a difference between “aeration” and “natural air-drying” of the grain, and it is the latter that we should be using. Aeration = grain conditioning/cooling --> low airflow rate (0.1-0.2 cfm/bu); whereas natural air-drying = removing moisture from grain --> high airflow rate (1-2 cfm/bu).
For those without a grain dryer, waiting for the crop to dry down, especially crops that have been flattened by a snowfall will be a painful process of waiting and may rely on a neighbour with a dryer or other means to dry down the crop once off the fields. One good thing is that temperatures are likely to stay cool from here on out, meaning any wet crop that has come off will not heat up in a bag or bin for perhaps a month or more if no aeration or supplemental heat is added to the system. Please refer to the chart “Effect of Temperature and Moisture Content on Allowable Storage Time of Wheat, Oats and Barley” on our website https://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/crop1204 as it is different per crop-type (different air spaces between the grains) and period of time planned for storage, but generally the cooler the grain the longer it can be stored. See also Canadian Grain Commission’s website for details on how long you can store wet grain, https://www.grainscanada.gc.ca/storage-entrepose/ssg-de-eng.htm.
A standing crop, or relatively erect, should be ready to combine sooner than a windrowed crop, simply because it is airier and you don’t have to wait for the centre or bottom of the windrow to dry down. Combining a tough cereal grain crop is different when temperatures are above freezing verses below freezing. A very small amount of snow still left in the windrow can work if it is say below -7 C, as it is cold enough that when the grain heats up passing through the combine, which it will, it remains below zero. A constant vigil on the equipment is critical as ice may build up on the cylinders and throw them out of balance, not to mention plugging of sieves etc. Combining frozen grain is not ideal, but if a period of sunny, -7 C or colder weather, with a light breeze and the snow is off the crop, it will be too irresistible to pass up. Combining grain above zero Celsius is much preferred. It needs to be dry enough to thrash and checking the loss out the back of the combine is an “all-day” venture, as conditions for tough grain can change quickly as the day moves on. It will likely quickly return to tough conditions as the sun starts to go down. If you have the combine set for tough conditions, (higher drum speed, tighter distance between abrasion plates, steeper angle on the sieve and stronger wind), you may crack the cereal seed or simply blow it out the back in the middle of the day when conditions are normally better. Frequent checking of the sieves and shakers screens for plugging from any damp straw and chaff will save you time and money in the long run; there is just a lot more checks with tough grain and speed is your enemy not your friend.